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jllaudio
2010-10-14, 07:48
I'm looking for a linear PS to replace the Walwart that came with the Touch. I would appreciate any recommendations.

Thanks,
jllaudio

garym
2010-10-14, 07:54
You may want to review this thread.

http://forums.slimdevices.com/showthread.php?t=81682&highlight=touch+power+supply

iPhone
2010-10-14, 07:57
I'm looking for a linear PS to replace the Walwart that came with the Touch. I would appreciate any recommendations.

Thanks,
jllaudio

Hello and Welcome to the Forum. Recommendations: save your money and put it toward a great DAC or Transporter. Paying more then $25 for a power supply makes no sense with the Touch.

Quick Question, WHY? Is your wall-wart PS bad? Is it causing a ground loop?

Cost wise and audio benefits wise replacing the OEM Power Supply doesn't make sense when the OEM is just fine. They did a very good job on the internal regulators on the Touch and it has internal switching supplies so replacing the OEM switcher accomplishes nothing as its really only acting as the supply voltage just as the AC power cord does on ones Amplifier.

gmudunuri
2010-10-14, 11:50
I tried the Welborne PS with my Duet. To my ears, it made absolutely no difference when listening to the digital output via my DAC. Maybe there was little difference on the analog out. If anything the stock switching PS is mechanically quieter than the Welborne PS, which has a slight - but audible - mechanical hum from the transformer.

praganj
2010-10-27, 01:44
I have built a diy PS for my Touch with SuperTeddyReg.

120VA transformator, rectifier bridge with fast diodes, 6800uF Panasonic cap and then SuperTeddyReg and good cables.

IMHO there is a huge sonical difference (using analogue or digital outputs) between delivered switched ps and well build high quality linear ps.

ralphpnj
2010-10-27, 06:47
I have built a diy PS for my Touch with SuperTeddyReg.

120VA transformator, rectifier bridge with fast diodes, 6800uF Panasonic cap and then SuperTeddyReg and good cables.

IMHO there is a huge sonical difference (using analogue or digital outputs) between delivered switched ps and well build high quality linear ps.

HUGH? - just how how HUGH? HUGH enough that anyone can hear the difference?

It's statements like "IMHO there is a huge sonical difference" that throw many people all into a tissy. Especially what such statements run counter to the experience of many of these people.

So please, do tell us just how HUGH is the difference with some specific examples, like deeper bass, clearer midrange, etc. TIA!

mooblie
2010-10-27, 06:53
So please, do tell us just how HUGH is the difference with some specific examples,like deeper bass, clearer midrange, etc. TIA!

Let me guess: it will be "airier sound stage, more ambience, like the performers are here with me, immediacy, increased commitment, more colour, less cramped expression, ......." Oh dear. This thread now belongs in Audiophiles.

ralphpnj
2010-10-27, 07:04
HUGH? - just how how HUGH? HUGH enough that anyone can hear the difference?

It's statements like "IMHO there is a huge sonical difference" that throw many people all into a tissy. Especially what such statements run counter to the experience of many of these people.

So please, do tell us just how HUGH is the difference with some specific examples, like deeper bass, clearer midrange, etc. TIA!


Let me guess: it will be "airier sound stage, more ambience, like the performers are here with me, immediacy, increased commitment, more colour, less cramped expression, ......." Oh dear. This thread now belongs in Audiophiles.

Thank you mooblie! See what I mean, praganj?

BTW, that is not knock against mooblie, it's just that mooblie was the first to respond.

praganj
2010-10-27, 07:44
I think that instead of writing about my spelling errors :) you should just try one good linear PS with your SBT.

Than you will have your own experience and you can report your findings here.

Phil Leigh
2010-10-27, 08:03
I think that instead of writing about my spelling errors :) you should just try one good linear PS with your SBT.

Than you will have your own experience and you can report your findings here.

We've been over this so many times. The digital output is completely unaffected by the external power supply (asuming it is supplying the right voltage and current and not injecting a ton of noise). There is no demonstrable/repeatable/provable audible or measurable difference (if anyone has any FACTUAL evidence, I'm all ears). Probably not what you wanted to hear. Ho-hum.



I'll leave it to others to comment on the analogue output.

Just because audio folk-lore insists that "improving" the power supply is always a good thing doesn't make it into a fact. Likewise the same folk-lore that insists that "linear" is always better than "switched" - which simply is NOT the case. Both are capable of good or bad results.

iPhone
2010-10-27, 09:42
We've been over this so many times. The digital output is completely unaffected by the external power supply (asuming it is supplying the right voltage and current and not injecting a ton of noise). There is no demonstrable/repeatable/provable audible or measurable difference (if anyone has any FACTUAL evidence, I'm all ears). Probably not what you wanted to hear. Ho-hum.



I'll leave it to others to comment on the analogue output.

Just because audio folk-lore insists that "improving" the power supply is always a good thing doesn't make it into a fact. Likewise the same folk-lore that insists that "linear" is always better than "switched" - which simply is NOT the case. Both are capable of good or bad results.

+1

I think you have hit the nail on the head here. It is a well known fact that on moderate gear with an AC power cord that putting money into the power supply can usually improve the devices audio. This is mainly due to the fact that this equipment is built to a price and improving the PS can sometimes do wonders. Additional most of these devices are powered by an AC cord and have internal power supplies with room inside to make mods. This having been the case for decades with Audiophiles seeing, hearing, and measuring the improvements has caused some to just think that replacing the PS with a supposed better one is always the first step toward Audio Nirvana.

The Touch has a decent Switching PS and great internal regulation. The Switcher is mainly just acting as the voltage supply as an AC cord would on ones pre-amp.

praganj
2010-10-27, 13:30
The switching power supply is creating HF noise.
This noise has not only negative effect on the Touch, but on all other hifi components in the system.
When for somebody switched ps is enough, than it is finally not my problem :)

Bill Burns
2010-10-27, 13:54
On 10/27/2010 4:30 PM, praganj wrote:
> The switching power supply is creating HF noise.
> This noise has not only negative effect on the Touch, but on all other
> hifi components in the system.

I'll be interested to see the spectrum analyzer results from your test
of the power supply in a shielded room.

--
Bill

praganj
2010-10-27, 14:30
No problem:

http://pinkfishmedia.net/forum/showpost.php?p=1099022&postcount=12

The whole thread:

http://pinkfishmedia.net/forum/showthread.php?t=81910

:)

Bill Burns
2010-10-27, 15:44
On 10/27/2010 5:30 PM, praganj wrote:
> No problem:
>
> http://pinkfishmedia.net/forum/showpost.php?p=1099022&postcount=12
>
> The whole thread:
>
> http://pinkfishmedia.net/forum/showthread.php?t=81910

Thanks! Now how about the double-blind listening tests?

--
Bill

iPhone
2010-10-27, 17:05
The switching power supply is creating HF noise.
This noise has not only negative effect on the Touch, but on all other hifi components in the system.
When for somebody switched ps is enough, than it is finally not my problem :)

HELLO, the Touch has two switching power supplies INSIDE its case! What does one outside have anything to do with anything. More importantly just because the wall wart has HF noise doesn't mean its getting back into the Touch audio or other equipment. Anybody with any common sense has the wall wart plugged into the wall or a power strip away from the rest of their equipment and not into the back of an outlet on his/her A/V Receiver.

This is a non-issue in most cases.

praganj
2010-10-28, 00:38
HELLO, the Touch has two switching power supplies INSIDE its case! What does one outside have anything to do with anything. More importantly just because the wall wart has HF noise doesn't mean its getting back into the Touch audio or other equipment. Anybody with any common sense has the wall wart plugged into the wall or a power strip away from the rest of their equipment and not into the back of an outlet on his/her A/V Receiver.

This is a non-issue in most cases.

This is all theory. The most important is the sound quality. I will not convince you that swiss "Lindt" chocolate taste better than some cheapy from Wallmart, even when the ingredients on the package are the same. You have to eat it, than you know the taste.

I think everybody should do his own experience not depending on some opinions and theoretical discussions. Musical Fidelity VDac has also two switching ps inside, but a good extern linear ps improve the sound a lot. The same is for SB Classic - it has also (2?) switching chips inside and sounds MUCH better with linear PS.

The main switching ps has to change 230V AC into 5V DC. It is much harder and different job, than switching inside the box from 5 V DC to +- 5V Volts (maybe it is +-12 V DC, i am not sure).

toby10
2010-10-28, 08:35
Indeed, listen and compare for yourself.

But also keep in mind your perceived benefit of improved audio quality using such a ps is every bit as much a theory as is the theory that there is no actual audio quality improvement. ;)

tubesguy
2010-10-28, 12:37
Indeed, listen and compare for yourself.

But also keep in mind your perceived benefit of improved audio quality using such a ps is every bit as much a theory as is the theory that there is no actual audio quality improvement. ;)

Hate to be a nudge, but there is actually a person who has measured, and the results are here:

http://forums.slimdevices.com/showpost.php?p=348177&postcount=3

Please keep this in mind when someone tells you, as has been repeatedly stated here, that because there are switching power supplies within the various Squeezeboxes, a linear supply _cannot_ make a difference in the measured results. It can. Whether that makes an audible diffence, of course, is a different question, and Pat does not venture an opinion.

Also keep in mind that some of the folks that make statements of "scientific" certainty are in fact about as scientific as the early Popes, and are determined not to let a few facts get in the way of their opinions.

Phil Leigh
2010-10-28, 12:43
Hate to be a nudge, but there is actually a person who has measured, and the results are here:

http://forums.slimdevices.com/showpost.php?p=348177&postcount=3

Please keep this in mind when someone tells you, as has been repeatedly stated here, that because there are switching power supplies within the various Squeezeboxes, a linear supply _cannot_ make a difference in the measured results. It can. Whether that makes an audible diffence, of course, is a different question, and Pat does not venture an opinion.

Also keep in mind that some of the folks that make statements of "scientific" certainty are in fact about as scientific as the early Popes, and are determined not to let a few facts get in the way of their opinions.

Pat was measuring the older (original - pretty bad) style switcher not the current one. Also, he was measuring the analogue output...

m1abrams
2010-10-28, 14:32
The switching power supply is creating HF noise.
This noise has not only negative effect on the Touch, but on all other hifi components in the system.
When for somebody switched ps is enough, than it is finally not my problem :)

And a rather large power transformer creates a good bit of EMF noise. Place that transformer anywhere near a line level signal and you will induce a nice 60hz hum.

FYI you really do not need a 120VA transformer to power a device that at most needs 15Ws. A 25-50VA transformer should be plenty and would produce less EMF.

toby10
2010-10-28, 15:10
Pat was measuring the older (original - pretty bad) style switcher not the current one. Also, he was measuring the analogue output...

So.... I guess it's back to theory and ears. ;)

earwaxer9
2010-10-29, 18:39
Anyone used a battery supply for the Touch? - Just curious.

praganj
2010-10-30, 01:28
And a rather large power transformer creates a good bit of EMF noise. Place that transformer anywhere near a line level signal and you will induce a nice 60hz hum.

FYI you really do not need a 120VA transformer to power a device that at most needs 15Ws. A 25-50VA transformer should be plenty and would produce less EMF.

I know that 120VA is overkill, but look at Naim Audio and their power supplies for preamps. Why they are doing it ? Are they so stupid ?

Big transformator has lower impedance, than the small one. Good power suplly should have the lowest possible impedance.

Thats the reason why i took one 120VA :)

Phil Leigh
2010-10-30, 03:48
I know that 120VA is overkill, but look at Naim Audio and their power supplies for preamps. Why they are doing it ? Are they so stupid ?

Big transformator has lower impedance, than the small one. Good power suplly should have the lowest possible impedance.

Thats the reason why i took one 120VA :)

1) They are not stupid. They know that nobody is going to pay £300+ for the 20VA that is required...
2) The SB will never see the "impedance" of the transformer. It will see the regulation circuitry...

praganj
2010-10-30, 07:11
Hi Phil,

Power supply is just one electric circuit build from few elements.

The impedance of the power supply in our case is composed of the impedance of the reg + main caps + rectifier + transformator. This is very simple rule of physics (or electric if you like).

Some companies trying to lower the impedance are using rectifier with two diodes instead of four and the transformator has to be made of thicker, harder wire, than it has lower impedance.

Phil Leigh
2010-10-30, 07:29
Hi Phil,

Power supply is just one electric circuit build from few elements.

The impedance of the power supply in our case is composed of the impedance of the reg + main caps + rectifier + transformator. This is very simple rule of physics (or electric if you like).

Some companies trying to lower the impedance are using rectifier with two diodes instead of four and the transformator has to be made of thicker, harder wire, than it has lower impedance.

Hi
I know how to build power supplies, which is I why I also know that you don't need over-sized transformers on line level circuits and why you won't get full-wave rectification from just 2 diodes...unless you use an (expensive) centre-tap transformer.

The performance of the PSU is predominantly determined by the smoothing caps and the voltage regulator. Using an oversize transformer to support a mere 3 amps at 5v is just a waste of money. There's also transformer ringing to consider...

ralphpnj
2010-10-30, 09:26
Hi
I know how to build power supplies, which is I why I also know that you don't need over-sized transformers on line level circuits and why you won't get full-wave rectification from just 2 diodes...unless you use an (expensive) centre-tap transformer.

The performance of the PSU is predominantly determined by the smoothing caps and the voltage regulator. Using an oversize transformer to support a mere 3 amps at 5v is just a waste of money. There's also transformer ringing to consider...


"But it sounds better!"

The standard audiophile response whenever they are presented with clear scientific facts regarding the latest, greatest and very expensive after market upgrade. See also high priced USB and Cat 5 cables.

Still to come: air purification systems which will claim to improve the signal transmission of one's home wi-fi system resulting in much better sound and sharper video for all streaming devices. And of course the first ever truly high end router complete with gold plated connections and a fully regulated linear power supply, all for a mere $2,500 excluding Cat 5 cables.

Hey Phil perhaps we can become partners in the first "audiophile air" company!

mooblie
2010-10-30, 10:04
And of course the first ever truly high end router complete with gold plated connections and a fully regulated linear power supply, all for a mere $2,500 excluding Cat 5 cables.
Well, those Cat 5 cables are already here for the suckers. (http://usa.denon.com/us/Product/Pages/Product-Detail.aspx?Catid=5840d55c-4077-4d9e-9421-36f204fb4587&SubId=85958de8-a123-4213-8ae1-bb6afaee9a97&ProductId=f7d26b3a-05a6-4724-a5c1-2a63642a6206) Directional, too! Don't the idiots EVER feel maybe, just maybe, they're being taken for a ride?

ralphpnj
2010-10-30, 10:25
Well, those Cat 5 cables are already here for the suckers. (http://usa.denon.com/us/Product/Pages/Product-Detail.aspx?Catid=5840d55c-4077-4d9e-9421-36f204fb4587&SubId=85958de8-a123-4213-8ae1-bb6afaee9a97&ProductId=f7d26b3a-05a6-4724-a5c1-2a63642a6206) Directional, too! Don't the idiots EVER feel maybe, just maybe, they're being taken for a ride?

I know about these outrageously priced cables but as of yet there are no "audiophile" routers on the market nor is there an air purification system for improving wi-fi signals available. So there still remains several good money making opportunities available :)

Phil Leigh
2010-10-30, 10:28
I know about these outrageously priced cables but as of yet there are no "audiophile" routers on the market nor is there an air purification system for improving wi-fi signals available. So there still remains several good money making opportunities available :)

On a (slightly) serious note regarding hi-fi air, it is worth getting an ioniser or two in the room...

ralphpnj
2010-10-30, 10:49
On a (slightly) serious note regarding hi-fi air, it is worth getting an ioniser or two in the room...

Phil, since I highly value your pragmatic, fact based approach, could you please briefly explain why one might need an ionizer?

praganj
2010-10-30, 12:00
Hi
I know how to build power supplies, which is I why I also know that you don't need over-sized transformers on line level circuits and why you won't get full-wave rectification from just 2 diodes...unless you use an (expensive) centre-tap transformer.

The performance of the PSU is predominantly determined by the smoothing caps and the voltage regulator. Using an oversize transformer to support a mere 3 amps at 5v is just a waste of money. There's also transformer ringing to consider...

Dear Phil,

I believe that you know how to build ps.

If i want to build the best possible ps using Superteddyreg than i am trying to use best possible components around it and a oversized high quality transformator with low impedance is IMHO a good choice, or is there something wrong about it ?

The main cap after rectifier is 6800uF. Most people will also say that it is too much, 2000 will be enough.

For me the price difference using better oversized components is maybe 20€. So what ?

m1abrams
2010-10-30, 13:34
Dear Phil,

I believe that you know how to build ps.

If i want to build the best possible ps using Superteddyreg than i am trying to use best possible components around it and a oversized high quality transformator with low impedance is IMHO a good choice, or is there something wrong about it ?

The main cap after rectifier is 6800uF. Most people will also say that it is too much, 2000 will be enough.

For me the price difference using better oversized components is maybe 20€. So what ?

Using an oversized transformer for the demands of the circuit is not just a waste of money but also BAD for your circuit. The larger the transformer the MORE emf it generates which is one of the big noise generators in audio.

Also an oversized transformer will produce higher voltage than needed for the circuit and cause your voltage regulators to work harder and produce more heat.

Unless you are connecting your amps directly to the transformers secondaries they they will NEVER see the "lower impedance" of the transformer. That should be handle by the PSU not the transformer.

JohnSwenson
2010-10-30, 14:18
OK, now that actual PS design is being talked about I'll jump into this thread. (I actually have a couple hours not at work today!!)

I've done a huge amount of PS testing, design and building in regards to the Touch and other devices, what I'm presenting here is not just conjecture, its been tested many times.

My conclusions are that a large percentage of improvements with PS design for the Touch are related to high frequency noise sent BACK into the mains and picked up by other components. power sent into the Touch itself has little impact on what goes on inside the Touch (not zero, but quite small). The differences in mains injected noise is vastly greater than any changes in the power actually delivered to the components inside the Touch.

Given this the focus of PS design should be on decreasing what gets sent back down the AC line, not making the absolute lowest noise, lowest impedance feed to the Touch. Many of the attempts at getting the "best" power to the Touch increase the noise sent down the line.

For a linear supply there are primarily three things that contribute to noise sent back down the line: reverse recovery noise when the diodes switch, transformer ringing and current spikes when the diodes conduct.

Using Schottky diodes can get rid of the reverse recovery noise, transformer ringing can be dealt with with an RC network across the secondary which damps the resonance. This damping of the transformer ringing is very effective but almost never done. If you go and look at 100 different linear PSs there will be a very high probability that NONE of them have damped the transformer resonance. Its intriguing that the higher the "quality" of the transformer the worse the resonance is, thus using expensive "high end" transformers is one of the worst things you can do. (unless you damp it)

The current spikes are the hard part. These are caused by the traditional PS design of transformer, diodes and a big cap. The diodes only conduct when the voltage from the transformer is greater than the voltage on the cap. Thus the power coming from the transformer is in short high current spikes. For example a common design for the 5V 2A for the Touch will actually have 20A spikes coming from the transformer. These 20A spikes have all kinds of high frequency components which get sent right back through the transformer and into the mains. They ALSO excite the above mentioned transformer resonance causing the transformer to ring like a bell, even if you use Schottky diodes.

The DC signal coming out of such a design is a sawtooth wave. This also has large amounts of high frequency components. Unfortunately most rectifier designs have very little input rejection at high frequencies, they do great at low frequencies, but at high frequencies not so good. This is one reason that discrete regulators have been used in audiophile designs, they can have much better high frequency input rejection, which is needed to correctly handle the sawtooth.

There is a solution, but its hardly ever used in low voltage PS designs. Its called a choke. Not the little high frequency things designed to run at 50KHz and up, but big heavy things which have significant inductance at 120Hz. If properly designed they allow continuous conduction through the transformer and rectifier, eliminating the high current spikes. Another advantage is that the output waveform is a pure sine wave, no high frequency harmonics.

Put the choke filter, transformer damping and Schottky diodes together and you have a supply that injects almost nothing back into the AC line and delivers a clean pure sine wave to the rectifier. With this you don't NEED a complicated expensive regulator.

I've put together a design using these principles, the schematic is at:

http://home.comcast.net/~johnswenson1/stereo/SB_5V.GIF

All the parts should be available at Mouser or Digi-Key. I'm sure there are other distributors in other parts of the world where you can get these parts.

You should be able to get all the parts for $75 or so.

Give it a try I think you will like this design.

John S.

praganj
2010-10-30, 14:40
Wow ! Great post and a nice schematics.

Thanks John :)

It looks i have to rebuild a little my ps - i have already schottkys, but two things - a coil and C+R before rectifier are missing.

JohnSwenson
2010-10-30, 17:02
Wow ! Great post and a nice schematics.

Thanks John :)

It looks i have to rebuild a little my ps - i have already schottkys, but two things - a coil and C+R before rectifier are missing.

Just be sure to use that choke and cap values, they have been carefully tuned to work properly, changing any of the values will give suboptimal results.

Have fun!

John S.

Phil Leigh
2010-10-31, 01:05
Interesting John.
My (modded) DAC already has Schottky's in place and there is a snubber across the transformer... plus my "mains filter" uses a choke (actually 2 chokes)...

Of course the fact that the parts are there doesn't guarantee it all works properly.
How would you measure the re-injected artifacts?
thx
Phil

praganj
2010-10-31, 02:01
Just be sure to use that choke and cap values, they have been carefully tuned to work properly, changing any of the values will give suboptimal results.

Have fun!

John S.

Hi John,

I have few questions:

1. What AC voltage should deliver the transformator and how big ;) should it be ?
2. R1 - 1W is enough ?
3. Can i use instead of LT1048 one superteddyreg and if yes, is C5 and C6 necessary ? Or should i just forget str and use LT1048 ?
4. When i am building it and measuring, what voltage exactly should be after choke and after reg ?

Thanks, p.

Phil Leigh
2010-10-31, 10:34
Phil, since I highly value your pragmatic, fact based approach, could you please briefly explain why one might need an ionizer?

All the electrical kit in your room gives off (low-level) ionic stuff - ionisers help to counteract that and rebalance the ionic levels in the air - makes you feel "more relaxed" etc - I'm not an expert on this stuff, but I do feel it is worth experimenting with these devices to create an atmosphere that is more conducive to various things, including listening to music. You need one per approx 15 sq meters of room. I've got 3 in my main listening room.
Obviously if you live in the countryside in the middle of nowhere it may not make much difference - you could just open a window...

However, I find (in a semi-rural setting) that they help. YMMV of course.

Ianmac
2010-10-31, 10:47
Thank you John for a very informative post.
It answers a few issues for which I have been searching for answers.

Ianmac

ralphpnj
2010-10-31, 11:15
All the electrical kit in your room gives off (low-level) ionic stuff - ionisers help to counteract that and rebalance the ionic levels in the air - makes you feel "more relaxed" etc - I'm not an expert on this stuff, but I do feel it is worth experimenting with these devices to create an atmosphere that is more conducive to various things, including listening to music. You need one per approx 15 sq meters of room. I've got 3 in my main listening room.
Obviously if you live in the countryside in the middle of nowhere it may not make much difference - you could just open a window...

However, I find (in a semi-rural setting) that they help. YMMV of course.

Thank you Phil for that in depth answer. Another thing that should help to relax one and make things like listening to music more rewarding is NOT obsessing over all these audiophile issues like linear power supplies and re-injected artifacts.Of course, YMMV ;)

JohnSwenson
2010-11-01, 11:58
Hi John,

I have few questions:

1. What AC voltage should deliver the transformator and how big ;) should it be ?
2. R1 - 1W is enough ?
3. Can i use instead of LT1048 one superteddyreg and if yes, is C5 and C6 necessary ? Or should i just forget str and use LT1048 ?
4. When i am building it and measuring, what voltage exactly should be after choke and after reg ?

Thanks, p.

1, this design uses 10VAC out of the transformer. A little larger won't hurt, it just means the the regulator has to dissipate more power. How big dpends on whether you will be running a USB disk drive off it. If not using a bus powered drive 25VA and up is fine. If you want to run a drive off this I would go for 50VA.

2. I'm using a 1/2W carbon composition resistor.

3. Sure you can use other regulators if you want, just make sure you have enough voltage for the regulator drop out. This design was tuned for the dropout of the LT1084, (I don't remember off the top of my head, you can look it up). If the regulator you want to use has a a greater drop out voltage you will have to up the voltage on the transformer. This design is very easy on transformers so you do not need to significantly over rate them.

4. You want the output to be 5V, it doesn't have to be super exact. 5.1 V will be fine, don't go much below. 4.98 is fine, but 4.8 might be too low. Don't go above 5.2 V. As to the output of the choke, that depends on the dropout of the regulator in use. If you are going for 5V out and your regulator needs 2V dropout, the output of the choke should NEVER go below 7V. Give your self a little margin.

John S.

JohnSwenson
2010-11-01, 12:13
Interesting John.
My (modded) DAC already has Schottky's in place and there is a snubber across the transformer... plus my "mains filter" uses a choke (actually 2 chokes)...

Of course the fact that the parts are there doesn't guarantee it all works properly.
How would you measure the re-injected artifacts?
thx
Phil

The chokes that one sees in PS designs are usually tiny little RF chokes, they are designed to work at MHz ranges. They do nothing at line frequencies. The ones I'm talking about are designed for line frequency (120 or 100Hz). Thats takes a big iron core and a lot of wire. The one speced in this design weighs several pounds and fills up your hand when you try and hold it. The choke is actually bigger than the transformer.

For measuring it I take a line voltage to 6V transformer, put a plug (and fuse!) on the primary and a resistive divider on the the secondary. Use a resistance that will draw a few mA, it doesn't need to be a lot. I run this into a spectrum analyzer, but you can send it into a line in of a soundcard and use FFT software.

Look at the results when plugged into different sockets, with different boxes plugged in. If using a soundcard it won't have enough bandwidth to see the 150KHz stuff unfortunately but you can still see a lot of the results of the current spikes.

This is one case where the bandwidth of a toroid is advantageous. Having said that I just use a cheap little 6V transformer from radio shack and it works fine.

John S.

Phil Leigh
2010-11-01, 12:17
The chokes that one sees in PS designs are usually tiny little RF chokes, they are designed to work at MHz ranges. They do nothing at line frequencies. The ones I'm talking about are designed for line frequency (120 or 100Hz). Thats takes a big iron core and a lot of wire. The one speced in this design weighs several pounds and fills up your hand when you try and hold it. The choke is actually bigger than the transformer.

For measuring it I take a line voltage to 6V transformer, put a plug (and fuse!) on the primary and a resistive divider on the the secondary. Use a resistance that will draw a few mA, it doesn't need to be a lot. I run this into a spectrum analyzer, but you can send it into a line in of a soundcard and use FFT software.

Look at the results when plugged into different sockets, with different boxes plugged in. If using a soundcard it won't have enough bandwidth to see the 150KHz stuff unfortunately but you can still see a lot of the results of the current spikes.

John S.

Ah - those chokes - like MF fit to some of their top-end gear... got it.

praganj
2010-11-02, 04:06
The ones I'm talking about are designed for line frequency (120 or 100Hz).

John S.

Hi John,

Is your ps design optimized for 50Hz or 60Hz line frequency ? Or both ? I need one for 50Hz ...

JohnSwenson
2010-11-02, 12:10
Hi John,

Is your ps design optimized for 50Hz or 60Hz line frequency ? Or both ? I need one for 50Hz ...

It works fine at 50Hz. The parts in question were actually designed for 50Hz use.

John S.

praganj
2010-11-02, 13:12
Thanks :)
Already ordered the Hammond choke and few other parts.

Ianmac
2010-11-11, 14:32
Just built a Linear power supply, not quite to John's design as I had difficulty getting a choke that would fit into the box size I had to work to.
I will fit a choke when I find a source.
There was an improvement to my system. Smoother treble more clarity and detail. Probably about the same as 1 1/2 to 2 db improvement in signal to noise
My Touch, DAC and CDP were all fed from the same mains distribution box.
My CDP performance improved cofirming to my mind that the Touch Wall Wart was dumping unwanted signals back onto the mains 'infecting' my DAC and CDP ( both have linear supplies). The improvement in DAC performance benefiting all its inputs.
A very worthwhile mod in my book and thanks again to John for sharing his knowledge.

Ianmac

Jo308
2010-12-01, 10:32
John,

how did you calculate the values of C & R on the transformer secondary?

Thanks,

Jo

JohnSwenson
2010-12-02, 17:11
John,

how did you calculate the values of C & R on the transformer secondary?

Thanks,

Jo

Jim Haggerman has a nice paper on the subject. In that he lists a procedure for measuring transformers to determine what values to use (its not a trivial test, but fortunately I had the right test equipment to do it). I ran this test on every transformer I had (about 25) and found out that even though the resonant frequency for these transformers varied all over the place the RC necessary to damp them wound up being remarkably similar. These values were sort of an average over the transformers I had. I then tried that combination on all of them and found that it worked fine for them all. So this has become my standardized value for all transformers. So far I have not found a transformer where this does not work.

John S.

Jo308
2010-12-03, 10:46
Thanks for the info John.

My new Touch is on the way in the post so I'll be building a PSU along these lines. And can try the secondary damping CR combo on a couple of other PSUs.

Jo

silence
2010-12-23, 10:45
Could the schematic for Johns powersupply be used for a PSU for the receiver too - if yes, is it just the LT1084 that should be changed?

JohnSwenson
2010-12-23, 17:59
Could the schematic for Johns powersupply be used for a PSU for the receiver too - if yes, is it just the LT1084 that should be changed?

What voltage does the receiver use? I dodn't remember if its 9 or 12. In either case you will need a different transformer, voltage for the regulator and maybe some different cap values. I might use a different Hammond choke too, since I think the receiver uses less current.

So it would pretty much be a different design (same schematic but different parts values)

I'd need the voltage and current draw to design such a version.

John S.

silence
2011-01-02, 13:15
Hi John - Happy New year. Forgot to subscribe to the thread so didn´t see your quick answer.

The receiver is 9V but only 0.5A. I don´t have the knowledge to calculate the right values, but I would be happy to report my results if you can help me with the right value for the schematic. I have a SB3 with a DIY linear power supply also - without a choke... , but with the LT1084 and I can definitely hear a difference using the analog out on the non-modded SB3. Will be introducing af DACMagic in a couple of days...

Torben

Good jazz on wma lossless or FLAC in to
DIY linear PSU> wired SB3> Qed LS75 coax > DacMagic> Harman Kardon HK6150>B&W DM620i
or
Standard PSU > wired SB receiver >atlas equator mk2> Cyrus 8vs2 >qed xt evolution > Dali Ikon on Wall and KEF psw-2000

paulster
2011-05-18, 09:18
John

+1 on calculating the LC filter values for the Receiver too.

That's a really neat design.

mudlark
2011-07-04, 11:23
My SB3 psu has blown up, what's the current best supply recommendation?

Cheers,
mike

lake_eleven
2011-08-19, 08:32
Any one used this PS on touch?

http://www.teradak.com/en/product_view.asp?ID=208

mjock3
2011-11-02, 14:35
What type of cap is used for C1?

Thanks,

Mark

HumanMedia
2011-11-22, 06:07
Big thanks for the great info.

mjock3
2011-12-23, 10:36
John,

Thanks a bunch for sharing your power supply with us. I recently got around to putting it together and am very impressed with the sound my Touch is producing. I just don't understand how a power supply can have such a profound affect on the sound that a piece of equipment produces.

Anyway much thanks and highly recommended.

Mark

TJHUB
2011-12-28, 14:22
John,

Thanks a bunch for sharing your power supply with us. I recently got around to putting it together and am very impressed with the sound my Touch is producing. I just don't understand how a power supply can have such a profound affect on the sound that a piece of equipment produces.

Anyway much thanks and highly recommended.

Mark

I have Mark's power supply on loan right now. I am completely amazed how well this power supply performs. I currently use a stock Jerome linear, and I have heard the Bolder modded Jerome in my setup. This power supply is significantly better in every way. I'm having a hard time even listening with the Jerome in place again. I'm going to either build this supply myself, or get one of my electrical engineer friends to build it so it's pretty (and done properly).

Terry

SandyRavage
2012-01-17, 07:17
Hi all,

I have a SB Classic on the stock power supply and did some Googling but all the LPS I've seen mentioned I can't find by part number anymore.

Does anyone know of a good budget LPS I can use with a SB3?

Not interested in the Bolder or RWA mod, just something to tinker around with and compare against the stock PS.

Thanks.

mjock3
2012-01-17, 08:25
Hi Sandy,

Here is a inexpensive Jerome one that is a step up from the stock. It is linear power supply. You would need to put on a new connector and figure out which wires were for the 5 volt supply. Here is a link: http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product_Code=TM93PWS2476&Category_Code=PWS

Mark

Waldo Pepper
2012-01-17, 12:54
You seem to have quite a following in your non science of acoustics and power supply design. Are you even qualified in any of the fields of electronics you comment on weekly?

I have designed power supplies for the last 25 years for audio and high end medical equipment and can only describe your postings as pants.

In the EU, power supply designs are very stringent on emissions, so to say a linear supply is better is totally non scientifically proven to be better than switchers in the audio band. Modern switchers when properly designed are far superior to heat generating linear supplies.

Ron Olsen
2012-01-17, 22:02
You seem to have quite a following in your non science of acoustics and power supply design. Are you even qualified in any of the fields of electronics you comment on weekly?

I have designed power supplies for the last 25 years for audio and high end medical equipment and can only describe your postings as pants.

In the EU, power supply designs are very stringent on emissions, so to say a linear supply is better is totally non scientifically proven to be better than switchers in the audio band. Modern switchers when properly designed are far superior to heat generating linear supplies.

For those not familiar with U.K. slang: http://dictionary.cambridge.org/dictionary/british/pants_2

SandyRavage
2012-01-18, 00:47
Hi Sandy,

Here is a inexpensive Jerome one that is a step up from the stock. It is linear power supply. You would need to put on a new connector and figure out which wires were for the 5 volt supply. Here is a link: http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product_Code=TM93PWS2476&Category_Code=PWS

MarkThanks .. any other options I can look at?

JohnSwenson
2012-01-18, 01:27
You seem to have quite a following in your non science of acoustics and power supply design. Are you even qualified in any of the fields of electronics you comment on weekly?

I have designed power supplies for the last 25 years for audio and high end medical equipment and can only describe your postings as pants.

In the EU, power supply designs are very stringent on emissions, so to say a linear supply is better is totally non scientifically proven to be better than switchers in the audio band. Modern switchers when properly designed are far superior to heat generating linear supplies.

Unfortunately I don't have time to make a full reply to this, its going to take some time to do it justice, I don't want to make a quick and dirty reply which does not fully represent my experience and research in this matter. I'm not blowing you off, I really do want to make a thorough and in depth response to this, but it's going to take some time to put it together, I don't want the reply to be pants as well, maybe at least a shirt.

John S.

JohnSwenson
2012-01-21, 19:33
OK, here is the in depth reply to Mr Pepper's inquiries.

I am an electronics engineer working for a semiconductor company (I'm not allowed to say which one), I layout integrated circuits, mostly large high speed digital with sensitive analog circuitry as well. My specialty is power distribution networks in these chips, providing low noise power and ground networks to provide very low jitter on the interface between the digital and analog sections. This jitter needs to be kept in the single digit ps range, which is not easy. In order to meet this we need on chip regulators, these regulators are always linear regulators, switching regulators simply produce too much noise.

At the system level we usually have a switching regulator on the board, followed by a linear regulator on the board and the linear regulator on chip. This is required in order to keep noise levels low enough so we can meet the jitter requirements. Believe me, if we could get away with a switching regulator on the chip we would do so.

As to my personal experience, I have designed many switching and linear regulators, I have only designed a few switching AC mains to DC supplies, but I have worked closely with those that do. I have measured many switching supplies, I have a fairly good good idea of what they can and cannot do. I have designed many linear AC Mains to DC supplies and measured those as well.

As to how this relates to audio, that is a long saga. Many years ago I was building audio DACs for myself and found out that what power supply I used had a significant impact on the sound. I set out to find out what differences in these supplies caused the difference. I ran many hundreds of tests with different supplies, listening and measuring the supplies and trying to come up with correlations, it was not easy and took a couple of years. One thing I learned from these tests was that most supplies feed a fair amount of noise back into the AC mains as well as the noise feed to the audio circuits. This noise injected back into the mains turned out to be one of the most important aspect of the tests, and one which is frequently completely ignored in power supply tests.

It turned out that frequency range that caused the most impact on sound quality was the 40KHz to 200KHz range. MHz and up was usually well controlled and filtered, and frequencies in the audio range were usually handled very well by the regulators in the circuits, but the intermediate frequencies were not well dealt with. And it was the amount of this noise injected back into the mains that had the most impact on sound quality, presumably by being carried to other components in the "stereo system" such as power amps and preamps. I tried this with many different audio systems, from inexpensive consumer systems, expensive audiophile systems, pro audio systems and all of them seemed to be susceptible to this incoming noise on their AC.

Many of these components contained "line filters" designed to block incoming noise, but most of those only seemed to be effective in the MHz and up range, having very little affect in the 40KHz to 200KHz range. I probed around inside these other components and watched what happened to this noise coming in over the AC mains and found many of these components actually had resonances in this range which significantly magnified incoming noise. In quite a few cases even if their own power supply was not generating noise in this region, the resonances wound up feeding significant noise into the circuitry when noise in the right range was on the AC.

So the summary of all these tests was that the biggest requirement for a PS was to not send noise in the 40KHz to 200KHz range back down the AC line, keeping noise out of the DC fed to the DAC also made an impact, but it actually was not as big a concern as what went to the mains. It also had to not be susceptible to noise in that range coming from OTHER components.

So I set out to design a PS that met these goals. Since this was going to be a onesie for my own use it was a lot easier to build a linear supply. I did a LOT of spice simulations trying out different topologies and components which eventually evolved to what I have today. I built several and proved that the real world did in fact closely match the spice results so I was quite confident that doing the exploration with spice was a reasonable approach.

The result is very different than most linear supplies. Most linear low voltage supplies employ a single stage very large value cap after a bridge regulator. This of course only conducts over a very narrow portion of the cycle, giving rise to very high current pulses in the transformer. Common rectifiers produce switching noise in the bad frequency range, with in conjunction with the current pulses cause the power transformer to ring like a bell right in the bad range. This noise goes right through the power transformer and into the mains. Even if you have a good regulator which blocks this noise from the circuit beeing fed from this supply, the noise still goes out to the mains.

My design attempts to alleviate these issues in several ways, first it uses Schottky rectifiers, second it uses a choke based asymetrical PI filter after the rectifiers. The first cap is much smaller than the second cap. The result is a supply which has cunduction over almost the entire cycle, thus no large current spikes. Having the small first cap allows the large conduction angle, but it also allows the filter to not need nearly as much minimum current as a true choke input filter. What comes out of the filter is almost pure sine wave which is very easy for the regulator to deal with. In a tgraditional linear supply the sawtooth output has a lot of high frequencies which are much harder for simple regulators do deal with. The third part is a damping network across the power transformer which damps the winding resonance so it will not resonante from noise coming in from the outside world.

The result of all this is a design which has extremely low noise injected back into the AC line and very low noise sent to the audio circuitry. It's simple, does not contain any custom components, no special "audiophile" parts, is easy for inexperienced DIYers to build. Is it the only design possible? of course not. Can a switching supply be made which can match this performance, almost certainly. But its not going to be nearly as simple, will probably need custom magnetics and could very well cost more money to make and will be way out of the range of a DIYer to build.

I have tested many commercially available switching supplies (certainly not all), designed for many different applications, including many that come with audio devices including some very expensive pro audio equipment and NONE of them bettered the noise levels of this simple linear supply. So while it is certainly possible that a switching supply good do as well or better, it does not seem that this is common in the market place. It is also true that most linear supplies are also very bad as well, and many linear supplies are worse than the switching supplies that people are replacing. I have NEVER said that a linear supply is always better than a switching supply.

If you would like to test these claims go ahead and build this design (its easy and not very expensive) and compare it to any of your switching designs, paying attention to what is injected back into the AC mains as well as what gets sent to the device, I'd be very interested to see how it stacks up with your switching desings. Oh yeah, and while you're at it try hooking them up to a Touch and see if you hear any differences.

Here is the schematic of the design mentioned above:

http://johnswenson1.home.comcast.net/stereo/SB_5V.GIF

John S.

praganj
2012-01-22, 03:53
Here is the schematic of the design mentioned above:

http://johnswenson1.home.comcast.net/stereo/SB_5V.GIF

John S.

Great post :)

Percival Sweetwater
2012-01-22, 05:36
Here is the schematic of the design mentioned above:

http://johnswenson1.home.comcast.net/stereo/SB_5V.GIF

John S.

Looks like a simple transformer, full wave rectifier and a voltage regulator, with a big choke and capacitor in the middle. Oh, and the word "Pannasonic" (with three n's) written somewhere.

Waldo Pepper
2012-01-22, 06:52
OK, here is the in depth reply to Mr Pepper's inquiries.

I am an electronics engineer working for a semiconductor company (I'm not allowed to say which one), I layout integrated circuits, mostly large high speed digital with sensitive analog circuitry as well. My specialty is power distribution networks in these chips, providing low noise power and ground networks to provide very low jitter on the interface between the digital and analog sections. This jitter needs to be kept in the single digit ps range, which is not easy. In order to meet this we need on chip regulators, these regulators are always linear regulators, switching regulators simply produce too much noise.

At the system level we usually have a switching regulator on the board, followed by a linear regulator on the board and the linear regulator on chip. This is required in order to keep noise levels low enough so we can meet the jitter requirements. Believe me, if we could get away with a switching regulator on the chip we would do so.

As to my personal experience, I have designed many switching and linear regulators, I have only designed a few switching AC mains to DC supplies, but I have worked closely with those that do. I have measured many switching supplies, I have a fairly good good idea of what they can and cannot do. I have designed many linear AC Mains to DC supplies and measured those as well.

As to how this relates to audio, that is a long saga. Many years ago I was building audio DACs for myself and found out that what power supply I used had a significant impact on the sound. I set out to find out what differences in these supplies caused the difference. I ran many hundreds of tests with different supplies, listening and measuring the supplies and trying to come up with correlations, it was not easy and took a couple of years. One thing I learned from these tests was that most supplies feed a fair amount of noise back into the AC mains as well as the noise feed to the audio circuits. This noise injected back into the mains turned out to be one of the most important aspect of the tests, and one which is frequently completely ignored in power supply tests.

It turned out that frequency range that caused the most impact on sound quality was the 40KHz to 200KHz range. MHz and up was usually well controlled and filtered, and frequencies in the audio range were usually handled very well by the regulators in the circuits, but the intermediate frequencies were not well dealt with. And it was the amount of this noise injected back into the mains that had the most impact on sound quality, presumably by being carried to other components in the "stereo system" such as power amps and preamps. I tried this with many different audio systems, from inexpensive consumer systems, expensive audiophile systems, pro audio systems and all of them seemed to be susceptible to this incoming noise on their AC.

Many of these components contained "line filters" designed to block incoming noise, but most of those only seemed to be effective in the MHz and up range, having very little affect in the 40KHz to 200KHz range. I probed around inside these other components and watched what happened to this noise coming in over the AC mains and found many of these components actually had resonances in this range which significantly magnified incoming noise. In quite a few cases even if their own power supply was not generating noise in this region, the resonances wound up feeding significant noise into the circuitry when noise in the right range was on the AC.

So the summary of all these tests was that the biggest requirement for a PS was to not send noise in the 40KHz to 200KHz range back down the AC line, keeping noise out of the DC fed to the DAC also made an impact, but it actually was not as big a concern as what went to the mains. It also had to not be susceptible to noise in that range coming from OTHER components.

So I set out to design a PS that met these goals. Since this was going to be a onesie for my own use it was a lot easier to build a linear supply. I did a LOT of spice simulations trying out different topologies and components which eventually evolved to what I have today. I built several and proved that the real world did in fact closely match the spice results so I was quite confident that doing the exploration with spice was a reasonable approach.

The result is very different than most linear supplies. Most linear low voltage supplies employ a single stage very large value cap after a bridge regulator. This of course only conducts over a very narrow portion of the cycle, giving rise to very high current pulses in the transformer. Common rectifiers produce switching noise in the bad frequency range, with in conjunction with the current pulses cause the power transformer to ring like a bell right in the bad range. This noise goes right through the power transformer and into the mains. Even if you have a good regulator which blocks this noise from the circuit beeing fed from this supply, the noise still goes out to the mains.

My design attempts to alleviate these issues in several ways, first it uses Schottky rectifiers, second it uses a choke based asymetrical PI filter after the rectifiers. The first cap is much smaller than the second cap. The result is a supply which has cunduction over almost the entire cycle, thus no large current spikes. Having the small first cap allows the large conduction angle, but it also allows the filter to not need nearly as much minimum current as a true choke input filter. What comes out of the filter is almost pure sine wave which is very easy for the regulator to deal with. In a tgraditional linear supply the sawtooth output has a lot of high frequencies which are much harder for simple regulators do deal with. The third part is a damping network across the power transformer which damps the winding resonance so it will not resonante from noise coming in from the outside world.

The result of all this is a design which has extremely low noise injected back into the AC line and very low noise sent to the audio circuitry. It's simple, does not contain any custom components, no special "audiophile" parts, is easy for inexperienced DIYers to build. Is it the only design possible? of course not. Can a switching supply be made which can match this performance, almost certainly. But its not going to be nearly as simple, will probably need custom magnetics and could very well cost more money to make and will be way out of the range of a DIYer to build.

I have tested many commercially available switching supplies (certainly not all), designed for many different applications, including many that come with audio devices including some very expensive pro audio equipment and NONE of them bettered the noise levels of this simple linear supply. So while it is certainly possible that a switching supply good do as well or better, it does not seem that this is common in the market place. It is also true that most linear supplies are also very bad as well, and many linear supplies are worse than the switching supplies that people are replacing. I have NEVER said that a linear supply is always better than a switching supply.

If you would like to test these claims go ahead and build this design (its easy and not very expensive) and compare it to any of your switching designs, paying attention to what is injected back into the AC mains as well as what gets sent to the device, I'd be very interested to see how it stacks up with your switching desings. Oh yeah, and while you're at it try hooking them up to a Touch and see if you hear any differences.

Here is the schematic of the design mentioned above:

http://johnswenson1.home.comcast.net/stereo/SB_5V.GIF

John S.

John

Thankyou for the prompt and in depth analysis of your circuit and your background. I have looked at the circuit and can find no reason why it would not work. A simple but highly effective well thought out design. Linear Tech devices take some real beating for quality comps.

I had made some meaurements on the 'Touch' supply as a 'Buck' convertor and found emissions to be well below any level that would cause problems. Maybe because of the low current drawn. Not quite sure I would want the same design topology for a power amp (which are normally not switchers).

From my findings, I am still not convinced that a linear PSU can have so much acoustic effect than a switcher....but that's the nature of Audiophiles who can hear the difference by changing their mains plug to one which costs >£500 regardless of what crap wiring is hanging behind the wall.

Best Regards
WTP

paulster
2012-01-22, 11:35
Thankyou for the prompt and in depth analysis of your circuit and your background. I have looked at the circuit and can find no reason why it would not work. A simple but highly effective well thought out design. Linear Tech devices take some real beating for quality comps.

I had made some meaurements on the 'Touch' supply as a 'Buck' convertor and found emissions to be well below any level that would cause problems. Maybe because of the low current drawn. Not quite sure I would want the same design topology for a power amp (which are normally not switchers).

From my findings, I am still not convinced that a linear PSU can have so much acoustic effect than a switcher....but that's the nature of Audiophiles who can hear the difference by changing their mains plug to one which costs >£500 regardless of what crap wiring is hanging behind the wall.


So, having called John out for his posts being 'pants', the best you can come up with is some conjecture, some unspecified measurements and absolutes (the level that would cause problems), and some more conjecture.

Nice rebuttal.

Now whose posts look like 'pants'?

beetof
2012-01-27, 04:15
In the scheme of John, do the stps-diodes need a heatsink?
Thanks anyone for answering.

paulster
2012-01-27, 10:48
In the scheme of John, do the stps-diodes need a heatsink?

No, they won't. They are rated for 20A and they would at this kind of current, but not for the load the Touch will present.

JohnSwenson
2012-01-27, 12:25
In the scheme of John, do the stps-diodes need a heatsink?
Thanks anyone for answering.

If you are running just a Touch they probably do not need heatsinking, but if you are going to be running a USB drive off the USB port you probably will.

John S.

beetof
2012-01-28, 01:19
Thanks Paul and John.

Phil Leigh
2012-01-29, 04:30
If you are running just a Touch they probably do not need heatsinking, but if you are going to be running a USB drive off the USB port you probably will.

John S.

On the other hand, if you are concerned enough about sound quality to be in the market for a replacement Touch power supply, you shouldn't be running a USB drive from it!:-)

The drive should have its own supply.

beetof
2012-01-29, 09:16
Music is on a Synology NAS (ethernetconnection via router). I plan to connect the NAS and Touch on a switch, that's connected to the router.
At the moment, I'm still using the Duet. I will order a Touch one of these days. Will control it with the Duet-controller.
I will try the software tweaks too (Tool 3.0).

And then a good DAC. But because the Touch's dac would be already pretty good (they say) I think an external Dac has to be a rather good one to make a difference. Will see.

I'm playing Sonus Faber Cremona Auditor M's with a Primaluna Dialogue one. Nice, but the only weak point I think is the acoustics of my living room (and the quality of my ears; I'm not that young any more) :-)

beetof
2012-04-04, 04:53
I built John's power supply. It works fine ... but has an unexpected result: in fact I've the impression it just works too good.

The Logitech supply sounds more pronounced, piano has more attack, the whole is finer. Pianonotes are more built in distinct steps.
With the DIY-supply, music sounds softer, more smoothing, more merging. Voices surely are warmer, but less sparkling. And the violin that always sounded fascinating gets boring after a while.

The Logitech output is 4,8V. The DIY exactly 5V. But in my opinion this can not give that difference.
I don't have an oscilloscope any more to compare the outputs.

I can't explain this. It seems as if the sound needs the noise from the Logitech ??

Soulkeeper
2012-04-04, 08:34
The Logitech output is 4,8V. The DIY exactly 5V. But in my opinion this can not give that difference.

Why not?

beetof
2012-04-05, 02:29
I don't know. But does every Logitech supply output 4,8V? I thought it was just tolerance from 5V.
So, within that tolerance, will every Touch sound that different? Seems me unbelievable.
Moreover, aren't there several regulators in the Touch?

beetof
2012-04-06, 06:58
No one with an idea what 's happening?

m1abrams
2012-04-06, 08:43
Not familiar with the psu you built however it could be a lot of things causing a change. If the new psu is unable to provide the current needed then it could be dropping out of regulation. This would cause pretty significant issues. Without testing the too supplies though it is anyone's guess.

What size transformer are you using?

beetof
2012-04-07, 00:31
Here is John's scheme:
http://home.comcast.net/~johnswenson1/stereo/SB_5V.GIF

The components are exactly as John mentioned.
The output is exactly 5V.
The transformer is 10Vsec / 2,5A.

As I said, it works fine, but it has the unexpected characteristic of smoothing too much. Is this the natural sound of the Touch (without noise effects)?

cfraser
2012-04-07, 09:18
What's John's opinion of multiple regulators in series?

For my convenience I built my linear PS with stuff I had. Hammond 4.8A dual-bobbin xfmr (I really like them!), Schottky diodes, LT1086 variable reg, Panny FCs. No choke (see [ ] below), but resonance control on the xfmr. That is the main PS, which is set to put out 7VDC. Second stage is a local regulator stuffed into a very tiny box which sits about 3" from the SBT, same regulating parts as the main PS. Allows me to put the larger main PS pretty much anywhere convenient. [It's not totally relevant to this particular discussion, but the PS is fed from balanced power which requires a certain physical placement which is nowhere near where my SBT is.] My SBT only draws about 0.4A (2W) pretty much continuously, so nothing gets very warm.

That said, the switcher included with the SBT is quite decent IMO for the wall-wart switcher genre, much much better than many others I have.

beetof
2012-04-07, 23:48
And what 's the difference in sound between the Logitech switcher and your PSU in your opinion?

cfraser
2012-04-08, 12:17
^ I'd say it's generally smoother, and a bit quieter. It has been so long since I did my PS comparisons though, I can't remember the details right now, but I did post them in one of the "Audiophile" forum linear PS threads (maybe look for one I started, I'd guess last summer). Background sonic quietness, the sense that the music is coming out of "pure" blackness, is the one area that the SBT can't touch (pretty cheap...) my best CD transport (via AES/EBU rather than S/PDIF) into the same DAC.

I have to say that balanced power (BP) makes more diff here than the linear PS did (pretty typical when applied to sources). And I tried a bunch of them, nothing fancy though. And I won't plug anything with switching PSs into my BP supply permanently, don't want to pollute it lol. So a linear PS wasn't really an option for me, unless I stop being a silly audiophile...

I have even run the SBT on a tightly regulated 6VDC, and it was fine. Then I tried a "6VDC" wall-wart, one rated for 600mA so its voltage at 400mA continuous draw wouldn't be too high (ones rated for higher current may put out 8-10V at low loads). This was fine too. Both of these were noticeably better than the stock switcher, and not much different than the "fancy" more proper PS I use. I am not recommending either of these BTW, I only did it because they are common items that I already had (6VDC is much more common for "adapters" than 5VDC) and I wanted to see the effect before I built something "better" or at least more permanent (and with a power switch).

Also bear in mind I am doing my "serious" listening through a system that has no op-amps in the audio circuits, and after the SBT is truly balanced (not balanced added on to single-ended). It is a VERY quiet system, BP sure helps that. I hear every little tiny thing, even when I don't want to... When I feed the SBT into my Denon AVR, like I'm listening to now, most of the HW/SW changes I've made/tried with the SBT have little to no sonic effect as far as I can tell. The preamp output cicuitry (cheap op-amps) of the AVR (and it's no bottom-liner either) is just too hazy and obscuring to be satisfying for me, but OK for background listening. Just saying that YMMV depending what the SBT feeds, so start slow/cheap (like I did with the adapters) before you go hog wild and then find out it makes little diff for all the effort.

Sorry for the rambling, I'm kinda loafing around today...

beetof
2012-04-12, 02:53
Yes, smoother, quieter, more relax, I recognize that. But did you notice a difference in attack (of, say, a piano)?

JohnSwenson
2012-04-12, 13:00
One of the big differences in My PS design VS the switcher and with many other linear designs is the major reduction in noise sent down the AC mains, so it may be less noise in the AC going to a power amp rather than the signal from the Touch.

The noise that this design gets rid of can cause IMD with high frequency components of your audio signal. For your piano attack this would cause a "sprinkling" of high frequency components around the attack, which you very well might hear as a "softening" of the attack. As was mentioned above this might actually be happening in the power amp rather than the Touch itself.

You have two choices now: go back to the way it was if you like that better, OR realize that with the new supply things are theoretically better and work on the rest of the system to improve it's transient response.

The latter is what I took up about 10 years ago. I realized that really good transient response was what was missing from my system and started tracking down what the culprits were and how to fix them. The result is that I have now built all my own speakers, amps, preamps, DACs, power cords, interconnects etc. The current system now has exceptionally good transient response and sounds amazing. But it wasn't easy to get there.

Along the way I found that a lot of audio equipment compresses transients, it seems to be something that a lot of designers kind of sweep under the rug. And it's not something that most audiophiles are prioritizing when selecting components so the designers don't feel a need to really spend a lot of effort on.

BTW I'm working on a new speaker design right now that is fairly small, inexpensive, easy to build and has very good transient response, I should have the prototypes built in a couple weeks.

John S.

m1abrams
2012-04-12, 14:21
One of the big differences in My PS design VS the switcher and with many other linear designs is the major reduction in noise sent down the AC mains, so it may be less noise in the AC going to a power amp rather than the signal from the Touch.

The noise that this design gets rid of can cause IMD with high frequency components of your audio signal. For your piano attack this would cause a "sprinkling" of high frequency components around the attack, which you very well might hear as a "softening" of the attack. As was mentioned above this might actually be happening in the power amp rather than the Touch itself.

You have two choices now: go back to the way it was if you like that better, OR realize that with the new supply things are theoretically better and work on the rest of the system to improve it's transient response.

The latter is what I took up about 10 years ago. I realized that really good transient response was what was missing from my system and started tracking down what the culprits were and how to fix them. The result is that I have now built all my own speakers, amps, preamps, DACs, power cords, interconnects etc. The current system now has exceptionally good transient response and sounds amazing. But it wasn't easy to get there.

Along the way I found that a lot of audio equipment compresses transients, it seems to be something that a lot of designers kind of sweep under the rug. And it's not something that most audiophiles are prioritizing when selecting components so the designers don't feel a need to really spend a lot of effort on.

BTW I'm working on a new speaker design right now that is fairly small, inexpensive, easy to build and has very good transient response, I should have the prototypes built in a couple weeks.

John S.

The question was why the stock psu had better piano attack, if I read your explanation correctly you describe why the stock psu would have worse attack by the introduction of high freq noise. Am I reading that wrong?

cfraser
2012-04-13, 12:16
Yes, smoother, quieter, more relax, I recognize that. But did you notice a difference in attack (of, say, a piano)?

Sorry, I couldn't say, not something I specifically compared, I don't listen to much piano either. I can say that lack of transient response is one of the main reasons I have for rejecting stuff. Makes music sound dull/unexciting. (It is one aspect of my mini rant re typical op-amps in audio circuitry.)

JohnSwenson
2012-04-13, 12:30
The question was why the stock psu had better piano attack, if I read your explanation correctly you describe why the stock psu would have worse attack by the introduction of high freq noise. Am I reading that wrong?

What I was trying to say is that the extra high frequency noise will increase the total energy in the attack which you may perceive as a stronger, more "forward sounding" attack.

John S.

NoRoDa
2012-04-13, 12:58
What I was trying to say is that the extra high frequency noise will increase the total energy in the attack which you may perceive as a stronger, more "forward sounding" attack.

John S.

I agree 100% !
This was actually what made it so easy to hear the difference between the Teddy Pardo TTouch PSU and the stock PSU when listening blind.
The percieved "more attack" is guaranteed due to more noice, sounds lively but harsh and noisy.

(It's the same thing that happends with the TT3.0 from Soundcheck, more noise/harshness vs the factory settings)

_R_

ismarketing
2012-04-13, 13:58
FWIW - I bought the Channel Islands Audio linear PSU about a year ago. Heard no difference on my Squeezebox classic (coax feeding a modded EAD Ovation) vs the stock supply. Also heard no difference on my Touch (coax feeding an Anthem D1) vs the stock supply.

Oddly, the stock Touch PSU sounds very slightly more open on the Classic than the stock Classic supply - they are both switchers.

My favorite - A surplus Cisco switching supply bought from a surplus store, fed by a Shunyata Venom power cord.

Your ears and perceptions will certainly vary.

Enjoy listening

cfraser
2012-04-13, 14:10
^ This why I suggested something cheap to test the waters, before going way out.

There is a fairly well-known DAC that is generally used with battery power. I am not the only one who thought it sounded best with a switching PS over a linear PS or different types of batteries (JIC it made a diff), IIRC the designer does too. So you never know... A lot depends on your local power situation, outside and inside your room, besides the rest of your system and your own taste.

An honest audiophile tosses tweaks that don't work *for them*. A "dishonest" one doesn't, keeps them because they were expensive and maybe pretty lol.

ajst2duk
2012-06-27, 23:50
OK, now that actual PS design is being talked about I'll jump into this thread. (I actually have a couple hours not at work today!!)

I've done a huge amount of PS testing, design and building in regards to the Touch and other devices, what I'm presenting here is not just conjecture, its been tested many times.

My conclusions are that a large percentage of improvements with PS design for the Touch are related to high frequency noise sent BACK into the mains and picked up by other components. power sent into the Touch itself has little impact on what goes on inside the Touch (not zero, but quite small). The differences in mains injected noise is vastly greater than any changes in the power actually delivered to the components inside the Touch.

Given this the focus of PS design should be on decreasing what gets sent back down the AC line, not making the absolute lowest noise, lowest impedance feed to the Touch. Many of the attempts at getting the "best" power to the Touch increase the noise sent down the line.

For a linear supply there are primarily three things that contribute to noise sent back down the line: reverse recovery noise when the diodes switch, transformer ringing and current spikes when the diodes conduct.

Using Schottky diodes can get rid of the reverse recovery noise, transformer ringing can be dealt with with an RC network across the secondary which damps the resonance. This damping of the transformer ringing is very effective but almost never done. If you go and look at 100 different linear PSs there will be a very high probability that NONE of them have damped the transformer resonance. Its intriguing that the higher the "quality" of the transformer the worse the resonance is, thus using expensive "high end" transformers is one of the worst things you can do. (unless you damp it)

The current spikes are the hard part. These are caused by the traditional PS design of transformer, diodes and a big cap. The diodes only conduct when the voltage from the transformer is greater than the voltage on the cap. Thus the power coming from the transformer is in short high current spikes. For example a common design for the 5V 2A for the Touch will actually have 20A spikes coming from the transformer. These 20A spikes have all kinds of high frequency components which get sent right back through the transformer and into the mains. They ALSO excite the above mentioned transformer resonance causing the transformer to ring like a bell, even if you use Schottky diodes.

The DC signal coming out of such a design is a sawtooth wave. This also has large amounts of high frequency components. Unfortunately most rectifier designs have very little input rejection at high frequencies, they do great at low frequencies, but at high frequencies not so good. This is one reason that discrete regulators have been used in audiophile designs, they can have much better high frequency input rejection, which is needed to correctly handle the sawtooth.

There is a solution, but its hardly ever used in low voltage PS designs. Its called a choke. Not the little high frequency things designed to run at 50KHz and up, but big heavy things which have significant inductance at 120Hz. If properly designed they allow continuous conduction through the transformer and rectifier, eliminating the high current spikes. Another advantage is that the output waveform is a pure sine wave, no high frequency harmonics.

Put the choke filter, transformer damping and Schottky diodes together and you have a supply that injects almost nothing back into the AC line and delivers a clean pure sine wave to the rectifier. With this you don't NEED a complicated expensive regulator.

I've put together a design using these principles, the schematic is at:

http://home.comcast.net/~johnswenson1/stereo/SB_5V.GIF

All the parts should be available at Mouser or Digi-Key. I'm sure there are other distributors in other parts of the world where you can get these parts.

You should be able to get all the parts for $75 or so.

Give it a try I think you will like this design.

John S.

I've been using this design for about 12 months now - great results. I use a commercially built Teddy power supply on my other one, at three times the price it doesn't sound any different. I just have a thing against loads of SMPS around the house.
Oh and hi forum members - AJ

jarrod2750
2012-07-29, 12:19
Is there member whom builds an updated power supply and sells them?

beetof
2012-08-01, 03:33
I'm quite willing to help you building a power supply, or building it together with you. But I doubt you are living in my neigbourhood.

R1200CL
2015-12-20, 10:29
OK, now that actual PS design is being talked about I'll jump into this thread. (I actually have a couple hours not at work today!!)

I've done a huge amount of PS testing, design and building in regards to the Touch and other devices, what I'm presenting here is not just conjecture, its been tested many times.

My conclusions are that a large percentage of improvements with PS design for the Touch are related to high frequency noise sent BACK into the mains and picked up by other components. power sent into the Touch itself has little impact on what goes on inside the Touch (not zero, but quite small). The differences in mains injected noise is vastly greater than any changes in the power actually delivered to the components inside the Touch.

Given this the focus of PS design should be on decreasing what gets sent back down the AC line, not making the absolute lowest noise, lowest impedance feed to the Touch. Many of the attempts at getting the "best" power to the Touch increase the noise sent down the line.

For a linear supply there are primarily three things that contribute to noise sent back down the line: reverse recovery noise when the diodes switch, transformer ringing and current spikes when the diodes conduct.

Using Schottky diodes can get rid of the reverse recovery noise, transformer ringing can be dealt with with an RC network across the secondary which damps the resonance. This damping of the transformer ringing is very effective but almost never done. If you go and look at 100 different linear PSs there will be a very high probability that NONE of them have damped the transformer resonance. Its intriguing that the higher the "quality" of the transformer the worse the resonance is, thus using expensive "high end" transformers is one of the worst things you can do. (unless you damp it)

The current spikes are the hard part. These are caused by the traditional PS design of transformer, diodes and a big cap. The diodes only conduct when the voltage from the transformer is greater than the voltage on the cap. Thus the power coming from the transformer is in short high current spikes. For example a common design for the 5V 2A for the Touch will actually have 20A spikes coming from the transformer. These 20A spikes have all kinds of high frequency components which get sent right back through the transformer and into the mains. They ALSO excite the above mentioned transformer resonance causing the transformer to ring like a bell, even if you use Schottky diodes.

The DC signal coming out of such a design is a sawtooth wave. This also has large amounts of high frequency components. Unfortunately most rectifier designs have very little input rejection at high frequencies, they do great at low frequencies, but at high frequencies not so good. This is one reason that discrete regulators have been used in audiophile designs, they can have much better high frequency input rejection, which is needed to correctly handle the sawtooth.

There is a solution, but its hardly ever used in low voltage PS designs. Its called a choke. Not the little high frequency things designed to run at 50KHz and up, but big heavy things which have significant inductance at 120Hz. If properly designed they allow continuous conduction through the transformer and rectifier, eliminating the high current spikes. Another advantage is that the output waveform is a pure sine wave, no high frequency harmonics.

Put the choke filter, transformer damping and Schottky diodes together and you have a supply that injects almost nothing back into the AC line and delivers a clean pure sine wave to the rectifier. With this you don't NEED a complicated expensive regulator.

I've put together a design using these principles, the schematic is at:

http://home.comcast.net/~johnswenson1/stereo/SB_5V.GIF

All the parts should be available at Mouser or Digi-Key. I'm sure there are other distributors in other parts of the world where you can get these parts.

You should be able to get all the parts for $75 or so.

Give it a try I think you will like this design.

John S.

Possible to a link that works to this PS ?

Julf
2015-12-20, 13:00
Possible to a link that works to this PS ?

Not sure this thread was worth bringing back - it should really be in the "audiophile" section. For anything digital, a well-designed SMPS is a much better solution than a linear supply.

Guy48065
2016-01-03, 21:07
Not sure this thread was worth bringing back - it should really be in the "audiophile" section. For anything digital, a well-designed SMPS is a much better solution than a linear supply.

Of course it's "worth bringing back" if it works--and judging by the deafening silence of the initial critics, it does.
I would also like to see working links to schematics to John's design.

Julf
2016-01-04, 05:49
Of course it's "worth bringing back" if it works--and judging by the deafening silence of the initial critics, it does.

Of course it "works", as in "still keeps powering the Touch". Still haven't seen any real proof it would actually provide any improvements. I am sure it still works as an excellent placebo.

As to "silence of initial critics", as long as the proponents don't provide any sort of non-anecdotal proof of their claims, what's the point of keeping repeating the same facts just so that someone can't claim that "critics have been silenced".

Yes, this discussion definitely belongs in the audiophile section.

Greg Erskine
2016-01-04, 12:50
Not sure this thread was worth bringing back - it should really be in the "audiophile" section. For anything digital, a well-designed SMPS is a much better solution than a linear supply.

Hi Julf,

What does "much better solution" actually mean?

regards
Greg

Julf
2016-01-04, 13:02
What does "much better solution" actually mean?

Lower internal resistance, higher peak current capability, much better suppression of HF noise, better regulation, higher efficiency, smaller size, lower weight.

pelliott321
2016-01-04, 14:38
The link on page 4 for the schematic for John's design no longer works
does anyone still have it or know how to get in touch with John

Greg Erskine
2016-01-04, 14:45
hi Julf,


cut %<.... higher efficiency, smaller size, lower weight.

Yes, always true, plus cheaper (in quantity), more expensive to design, less DIY friendly, less reliable.

regards
Greg

Greg Erskine
2016-01-04, 14:48
The link on page 4 for the schematic for John's design no longer works
does anyone still have it or know how to get in touch with John

But this link does: http://uptoneaudio.com/products/js-2-linear-power-supply :D

Jeff07971
2016-01-04, 14:53
Lower internal resistance, higher peak current capability, much better suppression of HF noise, better regulation, higher efficiency, smaller size, lower weight.

Whilst I would agree with you that a SMPSU for a SB is as good as is needed, of the 7 things you say that the SMPSU is better only 3 are correct.

A linear regulator will in general have better (Lower) internal impeadence due to the fact that the feedback bandwidth of linear regulators is generally higher that in a SM. SMPSU are limited in (real) bandwidth to the swiching frequency. A linear can be many MHz

Higher peak current is neither type, it depend on the current limiting system.

Switch noise is dominant noise in a SMPSU and is oreders of magnitute worse than a fairly bog standard linear.

Regulation is down to feedback bandwidth, linears win hands down.

higher efficiency, smaller size, lower weight SMPSU wins most of the time.

The best solution would be a SMPSU followed by a Linear, giving the low noise etc of a linear with most of the advantages of a SMPSU.


However theres still the regulator in the SB/Pi, In the Pi its a SM not sure about the SB's


Jeff

Greg Erskine
2016-01-04, 15:02
Whilst I would agree with you that a SMPSU for a SB is as good as is needed.

I should mention that I use the standard PSUs on all my Squeeze devices. When experimenting with other supplies I never found anything significantly better to make it worthwhile changing.

Subjectively, I found using an old XT PSU sounded different, IMO better, but ugly and inconvenient and not worth pursuing.

regards
Greg

Jeff07971
2016-01-04, 15:13
I should mention that I use the standard PSUs on all my Squeeze devices. When experimenting with other supplies I never found anything significantly better to make it worthwhile changing.

Subjectively, I found using an old XT PSU sounded different, IMO better, but ugly and inconvenient and not worth pursuing.

regards
Greg

I'm using a Meanwell RS-15-5 to power my Pi2/HifiBerryDAC+, I would have liked a linear psu for the analogue side of the DAC but was too complicated for the percieved benefit.

You can design a PSU to have the impeadence of a few inches of pcb track but you have to get it to the powered unit which makes it pointless.
Add to the the onboard regulator and it fait accompli !

I've never really tried blind listening but my systems sound great to me !

Jeff

Greg Erskine
2016-01-04, 16:04
I'm using a Meanwell RS-15-5 to power my Pi2/HifiBerryDAC+, I would have liked a linear psu for the analogue side of the DAC but was too complicated for the percieved benefit.

You can design a PSU to have the impeadence of a few inches of pcb track but you have to get it to the powered unit which makes it pointless.
Add to the the onboard regulator and it fait accompli !

I've never really tried blind listening but my systems sound great to me !

Jeff

Hi Jeff,

I use these things on my DIY DACs. Subjectively, I noticed a difference on the analogue side and little difference on the digital side.

http://users.tpg.com.au/gerskine/greg/jlh%20add-on%20shunt%20regulator.htm

The guy I design these PCBs for uses them everywhere in his DIY system, probably a dozen or more of them, and his system sounds wonderful to my cloth ears.

There are hundreds of these out there powering DACs, pre AMPs, AMPs, USB power, HD and SSD power. While I can't understand why, people seem to like them.

regards
Greg

Jeff07971
2016-01-04, 16:31
Hi Jeff,

I use these things on my DIY DACs. Subjectively, I noticed a difference on the analogue side and little difference on the digital side.

http://users.tpg.com.au/gerskine/greg/jlh%20add-on%20shunt%20regulator.htm

The guy I design these PCBs for uses them everywhere in his DIY system, probably a dozen or more of them, and his system sounds wonderful to my cloth ears.

There are hundreds of these out there powering DACs, pre AMPs, AMPs, USB power, HD and SSD power. While I can't understand why, people seem to like them.

regards
Greg

Hi Greg,

Well JLH is well respected and I've heard many good reports of that psu so if you've got them to hand !

I personally have used Ben Duncans 317/337 "wideband decoupling" regulator for both audio and small signal "scientific" amplifiers with great results, no digital circuits though.

Guy48065
2016-01-04, 19:15
But this link does: http://uptoneaudio.com/products/js-2-linear-power-supply :D

Is there a schematic there I may have missed? All I see is a very pretty, very expensive product.

Mnyb
2016-01-04, 20:42
Yes the squeezeboxes have several onboard small smps regulators the 5v is not enough for all its circuits .

Anyone having THD + noise measurement out of the analog output of squeezebox with the original psu vs an aftermarket unit ?
That's exactly what we want to see . And afaik no one has provided that everyone's just assumes that aftermarket psu is so much better due to the usual testimonials and sighted testing ( as the information content of a testimonial on a audiophile site is 0 , the amount of positive testimonials does not matter 0*x=0)

But most audiophiles uses the digital output to a DAC anyway ?

Johns supply design actually addresses another issue noise leaking back to the AC mains , here both kinds of supply can be really bad . And some amps and stuff can pick this up .

Getting rid of the classical diode bridge and transformer can't be bad . The switchmode way to rectify is way faster if you followed that by some good very fast regulators that can't be bad . But they got bad rep .

Also the compete design is a factor . My Meridian gear is full of smps supplies to no ill effect . The exception is the power amps in the active speakers .( and Meridian does not design the smps in house they are bougth )

The "big expensive power supply " is alway better is yet another audiophile myth .

There is such a thing as good enough supply for the intended use case . If the circuits don't need more current and the noise suppression in the design is good enough . Ou will reach a point where nominally better supplies actually does not improve the product anymore ( except in sighted listening tests ) .

Yes I do have an aftermarket supply ;) ( it's in my signature ,bougth it in my more audiophile days ).

As I remeber slimdevices did deliver a rather crummy 230v supply to the SB3 that unit was not up to any moder spec . Logitech later changed that and the late SB3 aka classic where delivered with the same supply as Touch which is a better speced compliant unit .

There is a reason PSU is a commodity that is bougth for outside suppliers . It does not effect product performance that much , it's not rocket science and reduces cost .

What do you make of NAIM's whole MO ;) that brand lives by selling expensive boxes with outboard psu in more expensive boxes....

Greg Erskine
2016-01-04, 22:11
Is there a schematic there I may have missed? All I see is a very pretty, very expensive product.

John doesn't visit us much here anymore. He is active on the site that I posted. JS-2 Linear Power Supply, the "JS" may be a clue. :D

Julf
2016-01-05, 02:36
Subjectively, I noticed a difference on the analogue side and little difference on the digital side.

It is a pity that nobody ever seems to bother verifying the subjective differences objectively, thus we never really know.

Julf
2016-01-05, 05:42
Higher peak current is neither type, it depend on the current limiting system.

A linear (shunt) regulator is limited to the series resistance/impedance of the transformer secondary, the rectifiers and the shunt element. A SMPS isn't.


Switch noise is dominant noise in a SMPSU and is oreders of magnitute worse than a fairly bog standard linear.

You are talking about the noise *generated* by the PSU - I was talking about immunity to noise from the powered device (which is why SMPSs are especially popular with digital equipment).

Jeff07971
2016-01-05, 05:46
A linear (shunt) regulator is limited to the series resistance/impedance of the transformer secondary, the rectifiers and the shunt element. A SMPS isn't.

So a SMPSU can supply infinite power ? What about the SMPSU's transformer and rectifier ?


You are talking about the noise *generated* by the PSU - I was talking about immunity to noise from the powered device (which is why SMPSs are especially popular with digital equipment).

No I'm not.


A linear (shunt) regulator

Most linear regulators are SERIES regulators BTW

Julf
2016-01-05, 05:56
Most linear regulators are SERIES regulators BTW

You are of course right. Brain fart on my part.

Jeff07971
2016-01-05, 06:04
You are of course right. Brain fart on my part.

No worries !

I don't want to start a flame war about psu's but a good linear PSU is by far the closest to "The perfect voltage source"

However difference in sound quality in mixed digital/analogue systems ? I agree with you and think minimal at best.

Jeff

Julf
2016-01-05, 06:22
However difference in sound quality in mixed digital/analogue systems ? I agree with you and think minimal at best.

Indeed - I think we can both agree that there are much more effective ways to try to improve sound quality.

Cheers!

stereoptic
2016-02-26, 07:15
Any suggestions for a moderately priced (<=$40) reliable power supply for the Squeezebox Touch? I see a few on ebay and amazon, some claim to be original logitech inventory, but I am often wary of that.

Man in a van
2016-02-26, 07:28
Any suggestions for a moderately priced (<=$40) reliable power supply for the Squeezebox Touch? I see a few on ebay and amazon, some claim to be original logitech inventory, but I am often wary of that.


Not linear,

I use several of these, (a dc barrel converter is required for the Touch)

http://uk.rs-online.com/web/p/desktop-power-supply/7212225/

This is a good battery if you want one (3amp output)

http://www.amazon.co.uk/Tonbux-20000mAh-Power-Bank-SmartPhones-Black/dp/B00SKH4J9S/ref=pd_sim_23_1?

stereoptic
2016-02-26, 08:00
Not linear,

I use several of these, (a dc barrel converter is required for the Touch)

http://uk.rs-online.com/web/p/desktop-power-supply/7212225/

This is a good battery if you want one (3amp output)

http://www.amazon.co.uk/Tonbux-20000mAh-Power-Bank-SmartPhones-Black/dp/B00SKH4J9S/ref=pd_sim_23_1?
Thanks! - I'll take a look at those when I get off from work (uk sites are restricted for some reason)

cdmackay
2016-02-26, 18:48
For those asking for a working link to John's schematic - if you Google search for the filename itself - SB_5V.GIF - you should find it, in a CA forum post.

Covenant
2016-02-28, 06:42
Any suggestions for a moderately priced (<=$40) reliable power supply for the Squeezebox Touch? I see a few on ebay and amazon, some claim to be original logitech inventory, but I am often wary of that.

I have one on ebay atm that looks like it will sell cheaply:

http://www.ebay.co.uk/itm/121903105072?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

stereoptic
2016-02-28, 09:10
I have one on ebay atm that looks like it will sell cheaply:

http://www.ebay.co.uk/itm/121903105072?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
Thanks for that.

pelliott321
2016-02-29, 08:05
For those asking for a working link to John's schematic - if you Google search for the filename itself - SB_5V.GIF - you should find it, in a CA forum post.

Everyone says it's on the web but I can not find it

Man in a van
2016-02-29, 08:37
Everyone says it's on the web but I can not find it


Try harder;):) post #5





http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/john-swensons-ps-design-25774/


Also look on images


https://www.google.co.uk/search?q=john+swenson+linear+power+supply&newwindow=1&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwikvtSdrJ3LAhUJnBoKHcDEARAQsAQIOA&biw=1280&bih=643#imgrc=c0FgH8YIegKuVM%3A

Peter314
2016-02-29, 16:36
Any suggestions for a moderately priced (<=$40) reliable power supply for the Squeezebox Touch? I see a few on ebay and amazon, some claim to be original logitech inventory, but I am often wary of that.

They are still available from Logitech.

http://support.logitech.com/en_us/product/squeezebox-touch

pelliott321
2016-03-01, 10:39
For those asking for a working link to John's schematic - if you Google search for the filename itself - SB_5V.GIF - you should find it, in a CA forum post.

What's the deal about this is it some big secret or something.

garym
2016-03-01, 10:41
What's the deal about this is it some big secret or something.

no. not a secret or big deal at all. Just a person's schematics for a home built linear power supply that may or may not be better than any other powersupply. As posted above, here's the schematic:

https://www.google.co.uk/search?q=john+swenson+linear+power+supply&newwindow=1&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwikvtSdrJ3LAhUJnBoKHcDEARAQsAQIOA&biw=1280&bih=643#imgrc=c0FgH8YIegKuVM%3A

If you're using a TOUCH for example, the likelihood of improving its audio with a non-stock powersupply is about zero.

Guy48065
2016-03-01, 12:44
Swenson's linear supply is just a basic 3-pin regulator chip? Is there something special about the LT1084 that's a big improvement over a LM317-vintage regulator?

Mnyb
2016-03-01, 13:48
Swenson's linear supply is just a basic 3-pin regulator chip? Is there something special about the LT1084 that's a big improvement over a LM317-vintage regulator?

Yes . But the thing when he designed this was the primary inductance "L1" a chunky 10mH thing this makes it a LC filtered supply on the primary side before the regulator . The supply is not as dirty to the network as many others .

Wonder if his write up on the design idea is still on this forum ?

Suppose the Touch has a bunch of internal switchers and regulators anyway .

Point of the exercise is that it's nothing magical with power supplies . A linear supply can also be dirty to the network just as switch modes can . This design fixes some of that but the 5 V side could probably have even better regulators if one wants to make it a project of some kind .

If it's good enough it's ok regardless of topology switch mode or linear .

This design is not super expensive . If I got it rigth ?

tcutting
2016-03-01, 15:26
Yes . But the thing when he designed this was the primary inductance "L1" a chunky 10mH thing this makes it a LC filtered supply on the primary side before the regulator . The supply is not as dirty to the network as many others .

Wonder if his write up on the design idea is still on this forum ?

Suppose the Touch has a bunch of internal switchers and regulators anyway .

Point of the exercise is that it's nothing magical with power supplies . A linear supply can also be dirty to the network just as switch modes can . This design fixes some of that but the 5 V side could probably have even better regulators if one wants to make it a project of some kind .

If it's good enough it's ok regardless of topology switch mode or linear .

This design is not super expensive . If I got it rigth ?

I looked at the schematic, and was surprised to see it seemed like almost a textbook linear PS. I think, as you noted, the main difference is he does some filtering around the main transformer/rectifier bridge to clean-up the voltage presented to the regulator IC.

paulster
2016-03-01, 15:44
I looked at the schematic, and was surprised to see it seemed like almost a textbook linear PS. I think, as you noted, the main difference is he does some filtering around the main transformer/rectifier bridge to clean-up the voltage presented to the regulator IC.

It's also an exceptionally quiet regulator. It really is in a league of its own at the moment. And the RC filter on the transformer is important too, to get rid of noise from the transformer itself.

It's just a very solid - if simple - design.

cdmackay
2016-03-01, 18:05
What's the deal about this is it some big secret or something.

No, it's just that John's original link no longer works, and there had been a few requests for it. It wasn't hard to find, but I thought I would point it out anyway, having just found it myself.

Guy48065
2016-03-01, 20:29
Well thank you for posting the link. I didn't know the file name and had no luck with other keywords.

I'm still considering what to use. The original ps burned up, a generic 4A switcher only lasted a month, now I'm using a little better (I hope) 6A switcher while I decide whether to use a linear supply.

The LT1038 was discontinued 15 years ago.
In looking into LT1084.

pelliott321
2016-03-02, 03:59
No, it's just that John's original link no longer works, and there had been a few requests for it. It wasn't hard to find, but I thought I would point it out anyway, having just found it myself.

Somebody must have the original somewhere
I know John has gone commercial now and understand him trying to protect his business but I just want to try this PS out not go into production

Jeff07971
2016-03-02, 05:15
Somebody must have the original somewhere
I know John has gone commercial now and understand him trying to protect his business but I just want to try this PS out not go into production

http://forums.slimdevices.com/showthread.php?82648-Linear-Power-Supplies&p=847577&viewfull=1#post847577

stereoptic
2016-03-02, 05:33
They are still available from Logitech.

http://support.logitech.com/en_us/product/squeezebox-touch

Wow, thanks for that. I had searched through the site and couldn't find it.

pelliott321
2016-03-02, 12:10
Now that's providing help
thanks

Mnyb
2016-03-03, 05:12
Logitechs spare site is really really hard to navigate ? There are more spares and stuff than you imagine :)

stereoptic
2016-06-19, 14:20
I've replaced the power supply and I am still having issues with the touch screen. It doesn't matter that much to me because I have become accustomed to using the remote or a wifi device to control the Squeezebox Touch.

However, occasionally while using the remote, the display fluctuates between the large text associated with using the remote and the small 'touch' text. Then the remote stops working and my only option is to unplug and replug.

Any suggestions? I am not adverse to opening up the unit and making some minor modifications. Otherwise, I may just replace it with the piCore/Jivelite.

Fizbin
2016-06-19, 17:13
Check out this thread:

http://forums.slimdevices.com/showthread.php?103192-IR-sensor-ALMOST-dead-any-cure/page3

stereoptic
2016-06-20, 04:37
Check out this thread:

http://forums.slimdevices.com/showthread.php?103192-IR-sensor-ALMOST-dead-any-cure/page3

Thanks for that. However, the remote works most of the time. The Squeezebox Touch screen is mostly unresponsive towards the top upper left, making it difficult to select the power on/off, or the top line of any menu.
So, I am thinking that the screen was damaged in some way.

Fizbin
2016-06-20, 15:49
Oops. I obviously didn't read your post carefully enough. That's a strange issue. I can see that arising if the unit was dropped but to just come on all of a sudden is perplexing. The fact that the remote stops working as well sounds like your Touch has one foot in the grave. Sometimes I see used ones on ebay, without remotes, go for silly money. I'd go that route, rather than taking your apart...unless you can identify the exact issue.

Mnyb
2016-06-20, 19:07
I've replaced the power supply and I am still having issues with the touch screen. It doesn't matter that much to me because I have become accustomed to using the remote or a wifi device to control the Squeezebox Touch.

However, occasionally while using the remote, the display fluctuates between the large text associated with using the remote and the small 'touch' text. Then the remote stops working and my only option is to unplug and replug.

Any suggestions? I am not adverse to opening up the unit and making some minor modifications. Otherwise, I may just replace it with the piCore/Jivelite.

If it fluctuates between large and small text , that suggest that it thinks someone has a finger on the screen :/ wonder if the screen is on its last leg

stereoptic
2016-06-21, 04:39
If it fluctuates between large and small text , that suggest that it thinks someone has a finger on the screen :/ wonder if the screen is on its last leg
That is what I am afraid of. I recently moved and although I had the Touch wrapped in bubble wrap, perhaps there was some pressure against the screen and it has not totally sprung back out.

Fizbin
2016-06-21, 05:40
'Funny' you should mention that. I was almost going to sell one of my Touches. I even went as far as packing it up. Even though it was in the original box I thought about putting bubble wrap around the unit. But I came to the conclusion that it would have made things worse because there is very little room between the box lid and the touch, so the bubble wrap would be pressing against the screen.

So, yeah, it's entirely possible.

stereoptic
2016-06-22, 04:16
Thanks. I may eventually try to open it if it gets too annoying.

R1200CL
2016-10-22, 02:48
Just let you know that the UpTone Audio new LPS-1 power supply will make a quite good improvement to your touch.
For what you get price is not bad. (And you can keep using your LPS)

http://uptoneaudio.com/products/ultracap-lps-1

Julf
2016-10-22, 07:57
Just let you know that the UpTone Audio new LPS-1 power supply will make a quite good improvement to your touch.

What specific aspects does it improve?

Fizbin
2016-10-22, 16:36
Just let you know that the UpTone Audio new LPS-1 power supply will make a quite good improvement to your touch.
For what you get price is not bad. (And you can keep using your LPS)

http://uptoneaudio.com/products/ultracap-lps-1

So you've compared this with the stock power supply? What differences are you're hearing? I would have to see some measurements to back your claim.

sckramer
2016-10-22, 18:49
Wow that looks insanely overengineered (or under, get it out the door) -- can there be any more components on that board?!? Isn't this Vinnie Rossi's idea?

ar-t
2017-03-30, 08:32
Hope no one minds if I jump into an old thread, but..................

We get questions about things of this nature, all the time. So, if I may be permitted, let me make this one observation.

We have noticed, from time to time, there was a 60 Hz spur, in our phase noise measurements. (Measuring and quantifying clocks is one of the main tasks, in the other side of the business.) It would come and go, and we had a hard time nailing down its cause.

Turns out it was the 5 V wall warts, that we sometimes used to warm up clocks, before sticking them in the main test fixture.

The reason I point this out it is the same brand, and model, that frequently comes with Squeezebox products.

Granted, this noise is pretty far down, in the noise. But, it is there, and we could occasionally see its effects.

Can anyone hear this, on their Squeezebox? I dunno.............maybe, maybe not. But, if we can measure it, the possibility exists that one can hear it.

For the record, other brands are as bad, or worse. Some models, of the same manufacturer, are better. The SMPS we have looked at seem to be all over the map, and there is no clear-cut good, or bad, brand/model.

LPS have their own issues.

The answer is there is no 100% correct answer. And we tossed a small handful, of wall warts, just to be sure.

R1200CL
2017-04-02, 13:21
What specific aspects does it improve?

Everything ;)

Sorry. I have not seen your question before now.

It's hard for me to describe, but in my friends setup the difference was really huge. You have to try for yourself to really believe.

You will find a lot more about how brilliant the LPS-1 is over at CA.

R1200CL
2017-04-02, 13:25
So you've compared this with the stock power supply? What differences are you're hearing? I would have to see some measurements to back your claim.

About measurements, please as Alex / Superdad or Johan Swenson over in the CA. (Computer Audiophile).

R1200CL
2017-04-02, 13:31
Isn't this Vinnie Rossi's idea?

I can't tell you who got the idea. The LPS-1 came out first. Yes it's same technology. Vinnie is spending money on having a patent. His PS is more expensive and have higher ratings.

You can serial connect the LPS-1 for higher voltage, but as a rule not parallel, so you are limited to 1,1 or 1,2 A.

Julf
2017-04-03, 03:47
You have to try for yourself to really believe.

Well, I have tried with a linear power supply, and didn't notice any change.


You will find a lot more about how brilliant the LPS-1 is over at CA.

I think "You will find a lot more about how brilliant the <tweak> is over at CA" is a valid statement for any value of <tweak> :)

R1200CL
2017-04-19, 15:16
Well, I have tried with a linear power supply, and didn't notice any change.

The LPS-1 is not a linear power supply. I would expect you to know better.

Most PS supplies won't make much difference on the SBT. The original supplied is quite good.

R1200CL
2017-04-19, 15:19
Quote from the producer:

Well the UltraCap LPS-1 is unique in being an extremely low impedance unit with cascaded ultra-low-noise (4uV rms from 10Hz to 100kHz) regulators.
And most importantly, as a bank alternating supply whose active output is 100% isolated from the charging side, it completely blocks the path of AC leakage currents, a important part of removing whatever it is powering from the "leakage loop" in that part of one's system (ALL audio systems have leakage loops happening between components with power supplies). The LPS-1 is a bit like a battery supply in this respect--without the several disadvantages of batteries.

slartibartfast
2017-04-19, 15:30
The LPS-1 is not a linear power supply. I would expect you to know better.

Most PS supplies won't make much difference on the SBT. The original supplied is quite good.
Uptone audio describe it as a linear power supply on their website.

Sent from my SM-G900F using Tapatalk

iPhone
2017-04-19, 17:33
Quote from the producer:

Well the UltraCap LPS-1 is unique in being an extremely low impedance unit with cascaded ultra-low-noise (4uV rms from 10Hz to 100kHz) regulators.
And most importantly, as a bank alternating supply whose active output is 100% isolated from the charging side, it completely blocks the path of AC leakage currents, a important part of removing whatever it is powering from the "leakage loop" in that part of one's system (ALL audio systems have leakage loops happening between components with power supplies). The LPS-1 is a bit like a battery supply in this respect--without the several disadvantages of batteries.


There is only ONE way to create a DC output without any AC artifacts especially when one starts with dirty residential AC power and that is to use a DC battery IE do not start by using ANY AC Power. A linear power supply can't really help the SB3 or the Touch since both have internal switching power converters (which are fairly well engineered because they knew they were dealing with audio and meeting a price point was the only reason for not spending more money to get power issues any lower). The design is actually good enough that it does take much more money that doesn't make sense spending to lower noise etc. Could the internal supplies be a little cleaner sure, but the cheapest way to get them cleaner and with much greater results is to by-pass them with the specific DC Voltage provided by external battery supplies.

I have tested a Touch and SB3 run off a battery supply instead of the AC Wall unit and using an HP Network Analyzer shows that it is really not worth the trouble. Yes there is an improvement from a purist point of view but considering that the Touch or SB3 is still going to be the weakest part of any expensive audio system it simply doesn't matter IE again its not worth bothering. Then looking at a system where the Touch isn't the weakest link in the audio path, it again doesn't matter because it would be impossible to hear any difference if the Touch isn't the weakest part because other equipment would either mask it or outright cover it up.

The solution to this supposed "Issue" is to simply buy a Transporter! SB3 and Touch are for streaming high quality digital files on good equipment. Transporter is for streaming high quality digital files on great (audiophile) equipment.

Julf
2017-04-20, 04:19
The LPS-1 is not a linear power supply. I would expect you to know better.

I wrote "I have tried with a linear power supply". Not the LPS-1.


Most PS supplies won't make much difference on the SBT. The original supplied is quite good.

I agree.

R1200CL
2017-04-21, 07:20
Not the LPS-1.

I hope you one day will have the chance 😀
You could borrow mine, but is's a lot of hazel since I'm in Norway, and in and out with customs.
(Also you will need a transition plug).

gregm
2017-05-03, 01:06
There is only ONE way to create a DC output without any AC artifacts especially when one starts with dirty residential AC power and that is to use a DC battery IE do not start by using ANY AC Power. A linear power supply can't really help the SB3 or the Touch since both have internal switching power converters (which are fairly well engineered because they knew they were dealing with audio and meeting a price point was the only reason for not spending more money to get power issues any lower). The design is actually good enough that it does take much more money that doesn't make sense spending to lower noise etc. Could the internal supplies be a little cleaner sure, but the cheapest way to get them cleaner and with much greater results is to by-pass them with the specific DC Voltage provided by external battery supplies.

I have tested a Touch and SB3 run off a battery supply instead of the AC Wall unit and using an HP Network Analyzer shows that it is really not worth the trouble. Yes there is an improvement from a purist point of view but considering that the Touch or SB3 is still going to be the weakest part of any expensive audio system it simply doesn't matter IE again its not worth bothering. Then looking at a system where the Touch isn't the weakest link in the audio path, it again doesn't matter because it would be impossible to hear any difference if the Touch isn't the weakest part because other equipment would either mask it or outright cover it up.

The solution to this supposed "Issue" is to simply buy a Transporter! SB3 and Touch are for streaming high quality digital files on good equipment. Transporter is for streaming high quality digital files on great (audiophile) equipment.

BOY is this guy opinionated!!!!!!!!!!!!!! :p:cool:

firedog
2017-05-03, 02:49
There is only ONE way to create a DC output without any AC artifacts especially when one starts with dirty residential AC power and that is to use a DC battery IE do not start by using ANY AC Power. A linear power supply can't really help the SB3 or the Touch since both have internal switching power converters (which are fairly well engineered because they knew they were dealing with audio and meeting a price point was the only reason for not spending more money to get power issues any lower). The design is actually good enough that it does take much more money that doesn't make sense spending to lower noise etc. Could the internal supplies be a little cleaner sure, but the cheapest way to get them cleaner and with much greater results is to by-pass them with the specific DC Voltage provided by external battery supplies.

I have tested a Touch and SB3 run off a battery supply instead of the AC Wall unit and using an HP Network Analyzer shows that it is really not worth the trouble. Yes there is an improvement from a purist point of view but considering that the Touch or SB3 is still going to be the weakest part of any expensive audio system it simply doesn't matter IE again its not worth bothering. Then looking at a system where the Touch isn't the weakest link in the audio path, it again doesn't matter because it would be impossible to hear any difference if the Touch isn't the weakest part because other equipment would either mask it or outright cover it up.

The solution to this supposed "Issue" is to simply buy a Transporter! SB3 and Touch are for streaming high quality digital files on good equipment. Transporter is for streaming high quality digital files on great (audiophile) equipment.

Thanks for the lecture. Too bad you don't have a clue what the LPS-1 product is or what it does. I you did, you wouldn't have written the above.

Jeff07971
2017-05-03, 02:55
Thanks for the lecture. Too bad you don't have a clue what the LPS-1 product is or what it does. I you did, you wouldn't have written the above.

So explain what the LPS-1 is and what it does then explain how it improves sound quality.

The electronics engineers amongst us would be interested

slartibartfast
2017-05-03, 06:50
So explain what the LPS-1 is and what it does then explain how it improves sound quality.

The electronics engineers amongst us would be interested
+1

Sent from my SM-G900F using Tapatalk

R1200CL
2017-07-16, 16:53
So explain what the LPS-1 is and what it does then explain how it improves sound quality.

The electronics engineers amongst us would be interested

https://community.roonlabs.com/t/logitech-transporter-vs-sonore-microrendu/21957/15?u=r1200cl

alfista
2017-07-16, 18:13
The LPS-1 is not a linear power supply.

From the Uptone Audio web page:


The LPS-1 is a single output, 1-amp linear power supply

Uptone is of course the company behind the venerable USB REGEN and similar products.

slartibartfast
2017-07-16, 22:54
https://community.roonlabs.com/t/logitech-transporter-vs-sonore-microrendu/21957/15?u=r1200cl
The key words would be "voodoo" and "unbelievable" then.

Sent from my SM-G900F using Tapatalk

Jeff07971
2017-07-17, 01:53
https://community.roonlabs.com/t/logitech-transporter-vs-sonore-microrendu/21957/15?u=r1200cl

Cant see any technical explanation of how it works, just some subjective views saying it does.

drmatt
2017-07-17, 04:20
Did I read that linked thread correctly? An external PSU on a SBT "improved the audio quality" when it's connected to an external DAC?


Transcoded from Matt's brain by Tapatalk

Apesbrain
2017-07-17, 06:15
Did I read that linked thread correctly? An external PSU on a SBT "improved the audio quality" when it's connected to an external DAC?
Incredible claims about all kinds of things are made every day by knowledgeable people and by those in authority. This thread is almost seven years old and no one to date has demonstrated that any of these add-on devices stand up to scientific scrutiny.

Credible findings with regard to many of these topics can be found in Archimago's blog: http://archimago.blogspot.com/

drmatt
2017-07-17, 10:27
I did read it correctly then....


Transcoded from Matt's brain by Tapatalk

r11bordo
2017-08-27, 06:40
The best power supply i have tested with SBT is a ifi ipower.

Julf
2017-08-27, 09:43
The best power supply i have tested with SBT is a ifi ipower.

Best in what way?

r11bordo
2017-08-27, 11:12
Great improvment regarding my last linear supply. I bought 2 others psu to power a w4s recovery and a usb-spdif interface dxio pro3z. The best improvment obtained is on the SBT, less obvious with the pro3z or the recovery.

Julf
2017-08-27, 12:41
Great improvment regarding my last linear supply. I bought 2 others psu to power a w4s recovery and a usb-spdif interface dxio pro3z. The best improvment obtained is on the SBT, less obvious with the pro3z or the recovery.

Improvement in what respect?

mherger
2017-08-27, 13:20
Juli,

Please take a break. You know very well yourself that you're asking for a useless argument.

Michael

> Am 27.08.2017 um 21:41 schrieb Julf <Julf.83wifz (AT) no-mx (DOT) forums.slimdevices.com>:
>
>
> r11bordo wrote:
>> Great improvment regarding my last linear supply. I bought 2 others psu
>> to power a w4s recovery and a usb-spdif interface dxio pro3z. The best
>> improvment obtained is on the SBT, less obvious with the pro3z or the
>> recovery.
>
> Improvement in what respect?
>
>
>
> "To try to judge the real from the false will always be hard. In this
> fast-growing art of 'high fidelity' the quackery will bear a solid gilt
> edge that will fool many people" - Paul W Klipsch, 1953
> ------------------------------------------------------------------------
> Julf's Profile: http://forums.slimdevices.com/member.php?userid=42050
> View this thread: http://forums.slimdevices.com/showthread.php?t=82648
>
>

r11bordo
2017-08-27, 23:16
Hi Juli,
Be curious, try yourself...

Julf
2017-08-28, 02:08
Please take a break. You know very well yourself that you're asking for a useless argument.

So making vacuous claims is OK, questioning them isn't?

mherger
2017-08-28, 02:44
> mherger wrote:
>> Please take a break. You know very well yourself that you're asking for
>> a useless argument.
>
> So making vacuous claims is OK, questioning them isn't?

No problem there, really. I just suggested you don't waste your time
(and those following the useless argument) because we already know the
outcome (or lack thereof).

--

Michael

Julf
2017-08-28, 03:03
No problem there, really. I just suggested you don't waste your time
(and those following the useless argument) because we already know the
outcome (or lack thereof).

Ack! We do have the "audiophile" section specifically for that kind of useless discussions.

Julf
2017-08-28, 03:05
Hi Juli

"Julf", not "Juli".


Be curious, try yourself...

What makes you think I haven't? Happy to continue the discussion in the audiophile section, where it belongs.

r11bordo
2017-08-28, 04:01
Hi Julf,
I looked the topic 'Linear power supply' and I replied. Any issue with that for you ?
No need for me to discuss on audiophile topic...
For information, I have compared a hdplex to a ifi ipower, same result for both.

Julf
2017-08-28, 04:17
I looked the topic 'Linear power supply' and I replied. Any issue with that for you ?


My issue was with you stating "great improvment" without clarifying what kind of improvement you were talking about. Power consumption? Price? Size? Ease of use? If the answer is "subjectively perceived sound quality", then the discussion definitely belongs in the "audiophile" section. In any case, I'll better follow the advice from Michael.

r11bordo
2017-08-28, 04:38
Overall improvment ... Reduced price, around 60€ and it exists only one 5V model. The hdplex tested was the 300 watts model. The SBT doesn't use competition voltage regulator, so, it seems logical to hear some effects with an optmized power supply.
On a W4S recovery, it is more difficult to hear an effect with a ifi ipower.

slartibartfast
2017-08-28, 05:06
Overall improvment ... Reduced price, around 60€ and it exists only one 5V model. The hdplex tested was the 300 watts model. The SBT doesn't use competition voltage regulator, so, it seems logical to hear some effects with an optmized power supply.
On a W4S recovery, it is more difficult to hear an effect with a ifi ipower.The interesting thing is that the ifi power supply does not appear to be a linear power supply. It has an input voltage range of 100V to 240V which is impossible for a linear supply.

https://ifi-audio.com/portfolio-view/accessory-ipower/


Sent from my SM-G900F using Tapatalk

Julf
2017-08-28, 05:27
The interesting thing is that the ifi power supply does not appear to be a linear power supply. It has an input voltage range of 100V to 240V which is impossible for a linear supply.

Good point. They don't claim it is linear, and it would be hard to make a linear power supply that small.

Mnyb
2017-08-28, 05:28
The interesting thing is that the ifi power supply does not appear to be a linear power supply. It has an input voltage range of 100V to 240V which is impossible for a linear supply.

https://ifi-audio.com/portfolio-view/accessory-ipower/


Sent from my SM-G900F using Tapatalk

That's actually refreshing. The belief that a certian design principle is always better is not good .

This whole tread is based on a myth that linear is always better for everything.

We can instead have good vs bad designs linier or switchmode .

And also does it really matter much when the ps is actually working as it should given how the Touch is designed ( not so much )

Jeff07971
2017-08-28, 05:30
I like the caveat at the buttom of this spec !

23519

jazzwave
2018-05-12, 21:53
I like the caveat at the buttom of this spec !

23519

I'm looking up-grade PS for my SBT, linear Power Supply (PS) was in my radar. But the good one (as informed in some forum) with >$300 price.
After read this thread , I decided to buy iPower 5V before jump to $400 linear power supply

Received iPower 5V last night, replaced the original SBT power supply.
I can hear the different compare to OEM, more quite, vocal more clear and enjoyable. No impact to soundstage, still same.
But I have to turn amp volume higher to have same level with OEM ps (suspected OEM deliver 3A and iPower only 2.5A)


Not bad for $49 solution...:cool:
So far I'm happy with this solution and save my money

~ron~

drmatt
2018-05-13, 10:22
Very weird. It shouldn't be quieter unless it's utterly underpowered and the voltage drops through the floor under load. And I would wager the SBT processor and screen uses a heck of a lot more power than the audio output stage.


Transcoded from Matt's brain by Tapatalk

iPhone
2018-05-13, 13:02
I'm looking up-grade PS for my SBT, linear Power Supply (PS) was in my radar. But the good one (as informed in some forum) with >$300 price.
After read this thread , I decided to buy iPower 5V before jump to $400 linear power supply

Received iPower 5V last night, replaced the original SBT power supply.
I can hear the different compare to OEM, more quite, vocal more clear and enjoyable. No impact to soundstage, still same.
But I have to turn amp volume higher to have same level with OEM ps (suspected OEM deliver 3A and iPower only 2.5A)


Not bad for $49 solution...:cool:
So far I'm happy with this solution and save my money

~ron~

.
April First has long passed so please don't post such incorrect rubbish based on your perception that your ears are somehow calibrated test equipment!
Output volume is NOT affected one bit by excess current, it is neither louder or lower output. And since the 2.5 Amp is close enough to spec (especially for the analog op-amp section), you aren't hearing any differences whatsoever! More over, the SBT has multiple internal switching supplies inside the unit so changing the external power supply as ABSOLUTELY NO EFFECT on the Touch performance as long as said PS delivers the minimum required voltage and current while being designed to use with audio equipment (clean enough). The Touch is NOT an audio amplifier driving speakers where available excess PS current is used to aid dynamic headroom! The only way to even remotely improve the output specs of the SBT is to disable the internal switching power supplies and feed those circuits directly with the proper DC voltage from battery sources. I have accomplished this and measured the improvement with actual test equipment, it however is not even remotely worth the time and expense to do this when one can just feed a high end DAC for a much better result using the Touch only as a file transport! I would not have done it if Caleb hadn't sent me a box full of "beyond bothering to repair" Squeezebox units! Simple way to prove this is to buy a 6VDC battery and feed your Touch with it! Zero ripple, zero noise, zero feedback, zero hum, zero ground loop, nothing but perfectly clean power with all the reserve current one can image if you use a 6VDC 10Ah rechargeable battery! You will not hear any difference unless the actual AC power supply you are currently using is DEFECTIVE!
Linear Power Supplies are a useless addition to a Touch as well as a waste of money with the SBT. No real improvement is possible (other then a slight improvement from using a battery as the external power source, especially if ones mains are really dirty with the switcher passing that onto the Touch).

philippe_44
2018-05-13, 14:22
@iPhone although you're technically correct, I'm not sure I see the benefit to start with an abrasive answer. It does not look like @jazzwave has been propagating some audiophile woo woo on this forum at all, so why not just (as you do in the second part of your post) explain him why his beliefs are incorrect? I'm not the police of this forum, needless to say but from time to time, for no good reason, it saddens me to see SB users (we are an endangered species) fighting for no reason, where education is what's needed.

iPhone
2018-05-13, 15:32
@iPhone although you're technically correct, I'm not sure I see the benefit to start with an abrasive answer. It does not look like @jazzwave has been propagating some audiophile woo woo on this forum at all, so why not just (as you do in the second part of your post) explain him why his beliefs are incorrect? I'm not the police of this forum, needless to say but from time to time, for no good reason, it saddens me to see SB users (we are an endangered species) fighting for no reason, where education is what's needed.

.
Who is fighting? I didn't see any fighting in my post and as you said, just actual Facts! My post was educating the obvious uneducated. An END needs to be brought to the never ending reviving of the Linear Power Supply Myth (especially when the unit getting said $300 Linear PS has internal switching supplies after the external PS)! Yes power supplies are important, but only the uneducated idiot buys a $300 Power Supply for a Touch that only retailed for $299!

Next is the silly premise that "it sounds better" with an out of spec PS, IE the "beholder" has magical calibrated ears but in reality actual has imagined everything to validate their actual lack of knowledge. Just exactly how does one go about attempting to "educate" somebody that can't apply knowledge and science because they depend on their perceived imagination? And of course, ones ears can easily discern certain things like the differences between listening to music from a 3 inch full range taped to a cardboard box versus a pair of home-brew three way speakers with poor cross-overs versus a pair of Vandersteen Model 7 speakers all being feed by Ayre Acoustics electronics! But when comparing ANY power supply against another with the Squeezebox Touch, no matter how great one's ears are, the only one that is going to actually sound different will be a defective power supply! There will be no increase or decrease in sound stage, no higher clearer highs, no deeper extended bass, IE no change whatsoever between in spec power supplies with the required minimum audio filtering!

So how does one "educate" these individuals, I'm all ears (pun intended)!

Kandiru
2018-06-01, 09:44
Another vote for iFi iPower.

Smooth sound on my separates system, subjective bias a possibility.

bakker_be
2018-06-02, 07:58
It's not the iPower, but just FYI regarding iFi power supplies: https://audiosciencereview.com/forum/index.php?threads/measurements-of-sonore-microrendu-streamer.577/

ar-t
2018-12-17, 11:21
Hope no one minds if I jump into an old thread, but..................

We get questions about things of this nature, all the time. So, if I may be permitted, let me make this one observation.

We have noticed, from time to time, there was a 60 Hz spur, in our phase noise measurements. (Measuring and quantifying clocks is one of the main tasks, in the other side of the business.) It would come and go, and we had a hard time nailing down its cause.

Turns out it was the 5 V wall warts, that we sometimes used to warm up clocks, before sticking them in the main test fixture.

The reason I point this out it is the same brand, and model, that frequently comes with Squeezebox products.

Granted, this noise is pretty far down, in the noise. But, it is there, and we could occasionally see its effects.

Can anyone hear this, on their Squeezebox? I dunno.............maybe, maybe not. But, if we can measure it, the possibility exists that one can hear it.

For the record, other brands are as bad, or worse. Some models, of the same manufacturer, are better. The SMPS we have looked at seem to be all over the map, and there is no clear-cut good, or bad, brand/model.

LPS have their own issues.

The answer is there is no 100% correct answer. And we tossed a small handful, of wall warts, just to be sure.

OK................another interruption, if you don't mind......................

Turns out some of our noise problems were also caused by the SMPS in our computer monitors. Solution to that problem turned out to be position of the monitor relative to our test gear. Sometimes turning it 90 degrees would fix it. Other times, it was more tricky to eliminate.

As before: can anyone actually hear these effects? I'll give that a definite possibly maybe qualified "well, it depends."

ar-t
2018-12-17, 11:31
OK, one more observation on SMPS. I'll try to be as brief as possible, which isn't always easy for a nerdy engineer.

Relative to 20-25 years ago, I can tell you the noise floor, in the 10 MHz region, is about 20 dB higher than it was back then. This is as measured off of an antenna we have strung up, for various "shortwave radio projects". (Don't ask why..............you really do not want to know.)

Below 10 MHz, it is worse, but we do not have any recorded data of what is was way back when. So, no way to say how much it has gotten worse, with the proliferation of SMPS, CFLs, and LED lighting.

And speaking of which................

If you have to replace a fluorescent ballast, they do make ones specifically for residential applications. Trying to find one at the local home improvement store might be tough. I believe some ham radio dorks sued the big one, because one of their worker drones said it was ok to use one designed for commercial use in their home.

(I have both, at my house. Both mess up hand-held SW radios, but I honestly can't tell you which one is which, using the radio as a measurement device.)

All for now! (Aren't you relieved?)

Jeff07971
2018-12-17, 11:45
OK, one more observation on SMPS. I'll try to be as brief as possible, which isn't always easy for a nerdy engineer.

Relative to 20-25 years ago, I can tell you the noise floor, in the 10 MHz region, is about 20 dB higher than it was back then. This is as measured off of an antenna we have strung up, for various "shortwave radio projects". (Don't ask why..............you really do not want to know.)

Below 10 MHz, it is worse, but we do not have any recorded data of what is was way back when. So, no way to say how much it has gotten worse, with the proliferation of SMPS, CFLs, and LED lighting.

And speaking of which................

If you have to replace a fluorescent ballast, they do make ones specifically for residential applications. Trying to find one at the local home improvement store might be tough. I believe some ham radio dorks sued the big one, because one of their worker drones said it was ok to use one designed for commercial use in their home.

(I have both, at my house. Both mess up hand-held SW radios, but I honestly can't tell you which one is which, using the radio as a measurement device.)

All for now! (Aren't you relieved?)

Do you know what I can do about the interference my Tesla coil causes ?

It really upsets my listening when the discharge hits me on the earlobe :D

cfuttrup
2018-12-17, 13:55
iFi power supplies: https://audiosciencereview.com/forum/index.php?threads/measurements-of-sonore-microrendu-streamer.577/

Thanks - I'll steer away from those ... :-)

/Claus

sgmlaw
2018-12-19, 15:42
OK, one more observation on SMPS. I'll try to be as brief as possible, which isn't always easy for a nerdy engineer.

Relative to 20-25 years ago, I can tell you the noise floor, in the 10 MHz region, is about 20 dB higher than it was back then. This is as measured off of an antenna we have strung up, for various "shortwave radio projects". (Don't ask why..............you really do not want to know.)

Below 10 MHz, it is worse, but we do not have any recorded data of what is was way back when. So, no way to say how much it has gotten worse, with the proliferation of SMPS, CFLs, and LED lighting.

And speaking of which................

If you have to replace a fluorescent ballast, they do make ones specifically for residential applications. Trying to find one at the local home improvement store might be tough. I believe some ham radio dorks sued the big one, because one of their worker drones said it was ok to use one designed for commercial use in their home.

(I have both, at my house. Both mess up hand-held SW radios, but I honestly can't tell you which one is which, using the radio as a measurement device.)

All for now! (Aren't you relieved?)

That is absolutely the truth. And it has gotten worse below 10 MHz, too. And it gets into everything. Passive mains filtering catches only some of it. Years ago, all I had to worry about was a little RF on the line and some compressor and motor noise that was manageable. Some of these new high E chargers and AC supplies are noise machines.

Fortunately, commercial OTA at the tower (here in the US) has gotten so poor in quality that it seems to balance out, and I don't feel I am missing anything anyway.

But I am probably going to start putting in some active measures soon to tamp down some of it, as noise wave-form cancelling technology has dramatically improved in the past 5 years.

Jeff07971
2018-12-19, 15:50
That is absolutely the truth. And it has gotten worse below 10 MHz, too. And it gets into everything. Passive mains filtering catches only some of it. Years ago, all I had to worry about was a little RF on the line and some compressor and motor noise that was manageable. Some of these new high E chargers and AC supplies are noise machines.

Fortunately, commercial OTA at the tower (here in the US) has gotten so poor in quality that it seems to balance out, and I don't feel I am missing anything anyway.

But I am probably going to start putting in some active measures soon to tamp down some of it, as noise wave-form cancelling technology has dramatically improved in the past 5 years.

A balanced isolation transformer and a well performed technical earth will get rid of most evils but if you have a SMPSU anywhere in you audio system......................

This is a good read if you're interested in high quality power http://www.britishaudio.co.uk/AQMSFLY1.htm

sgmlaw
2018-12-27, 10:53
A balanced isolation transformer and a well performed technical earth will get rid of most evils but if you have a SMPSU anywhere in you audio system......................

This is a good read if you're interested in high quality power http://www.britishaudio.co.uk/AQMSFLY1.htm

I now prefer active filtration in parallel, as isolation transformers and other in-line mains regeneration methods become extremely bulky (and increasingly expensive and inefficient) where higher current delivery is involved.

The former's technology has finally matured where it is genuinely effective, and unlike a transformer, gets out of the way of my amperage stream.

R1200CL
2019-05-10, 09:41
I'm looking for a linear PS to replace the Walwart that came with the Touch. I would appreciate any recommendations.

Thanks,
jllaudio

So did you try the Uptone LPS-1.2 (https://uptoneaudio.com/products/ultracap-lps-1-2) ? Or what PS did you try ?

More expensive options is the JS-2 (https://uptoneaudio.com/products/js-2-linear-power-supply) from same company. Or the Paul Hynes supply’s. But those I haven’t tried myself.