PDA

View Full Version : Yet another "what amp for my SB question"



GRC
2013-02-15, 14:40
Well despite the general doom and gloom about the demise of SB devices (nothwithstanding the community-funded thread) I'm still enjoying my little Squeezeboxen and waiting for used prices to settle down a bit so I can get some more. In the mean time, I recently bagged a brace of JBL Control One speakers in almost-new condition at a great price and I want to stick 'em on the end of a spare Squeezy. I'd forgotten how much I like these JBL beauties, but they do need a bit of welly to sing. I connected my little Topping TP-20 MKII but it runs out of steam just as the Control Ones start to boogie. The Topping TP-60 looks interesting but is much more expensive.

So - any suggestions for a small straight-forward minimalistic line-level amp offering - say - upwards of 30W RMS per channel into 8 ohms (and not at 10% THD!)? Happy to buy used gear. Budget - how about 150 sterling / 175 euros / $230 US dollars? There's plenty above that budget (e.g used Cyrus Straight Line, Nu-Force) but I figure it's a decent break point for used gear at least. I know I can get some old Rotel / Denon / Sansui / Teac / whatever stuff below that price but I'd like something physically small and all I want is an on-off switch and a volume control.

Thanks.

garym
2013-02-15, 17:34
Well despite the general doom and gloom about the demise of SB devices (nothwithstanding the community-funded thread) I'm still enjoying my little Squeezeboxen and waiting for used prices to settle down a bit so I can get some more. In the mean time, I recently bagged a brace of JBL Control One speakers in almost-new condition at a great price and I want to stick 'em on the end of a spare Squeezy. I'd forgotten how much I like these JBL beauties, but they do need a bit of welly to sing. I connected my little Topping TP-20 MKII but it runs out of steam just as the Control Ones start to boogie. The Topping TP-60 looks interesting but is much more expensive.

So - any suggestions for a small straight-forward minimalistic line-level amp offering - say - upwards of 30W RMS per channel into 8 ohms (and not at 10% THD!)? Happy to buy used gear. Budget - how about 150 sterling / 175 euros / $230 US dollars? There's plenty above that budget (e.g used Cyrus Straight Line, Nu-Force) but I figure it's a decent break point for used gear at least. I know I can get some old Rotel / Denon / Sansui / Teac / whatever stuff below that price but I'd like something physically small and all I want is an on-off switch and a volume control.

Thanks.

I've been very pleased with these:

http://www.amazon.com/Parasound-Zamp-v-3-Two-Channel-Amplifier/dp/B001RISK9M
http://www.audioadvisor.com/prodinfo.asp?number=PAZPRE2

ModelCitizen
2013-02-15, 23:34
I did the same thing and ended up buying this extremely small class t amp. Its a real beauty. Great sound and lots of welly. Fantastic value at 40 from eBay or Amazon.

Mini Audio Amplifier Muse M50 TPA3123 T-Amp 50W RMS

Mnyb
2013-02-16, 00:42
I did the same thing and ended up buying this extremely small class c amp. Its a real beauty. Great sound and lots of welly. Fantastic value at 40 from eBay or Amazon.

Mini Audio Amplifier Muse M50 TPA3123 T-Amp 50W RMS

Probably a great value for that little money but the TPA3123 chip is rated 2*25w at 4 ohm max 20w at 10% thd .
16w at 1% thd 4 ohm and 8 w at 1% thd 8ohm measured in the proper operating range at thd+N 0,08% it gives 5w at 8 ohm or 10w if you use one chip per ch and bridge them ( if the chip allows that ).

If you read further at the amazon spec page muse spec it as high performance guarantee 5W RMS 8 ohm so for OP perspective he should consider it a 5w power amp .

These class T and D amps suffer from a bit of creative specs so dividing the sales blurb power by a factor 4 - 10 is more like it .
another hint can be the rating of the power supply ,some of the cheaper amps does not utilise these chips fully due to under dimensioned wall wart .
To get the higher powers it should be feed >24 volts but muse includes a 14V 4Apower supply ?

But for the price you can't beat these things :) and a boxfull of them is probably a good option in large house in need of more zones

ModelCitizen
2013-02-16, 01:01
Well I never! The thing sounds great (punchy sound with lots of stereo separation) and is considerably louder than the 50watt rms convention Yamaha amp I had used previously.

I've never been one to subscribe to amps making a huge difference to sound quality. But, (as with class a valve amps) this one did make a noticeable difference.

Mnyb
2013-02-16, 01:02
This seems to be a nice multipurpose speaker http://www.jblpro.com/catalog/general/Product.aspx?PId=195&MId=5

The controll one spec says 87dB at 1w sensitivity but it is a 4 ohm speaker .

To me it means two things .

The amp should be really stable at 4ohm or preferably a bit lower , the simplest chip amps may not cut it .

If you want to compare sensitivity with 8 ohm speaker it really is 84dB ( the spec is really 2,83 volts at the terminals and this gives 2w in 4 ohm speaker ).
So this speaker is a bit power hungry .

So I would go for a normal class a/b amp or very stable class D amp of >50 per channel 8 ohm if it is of good design it would give around 100w 4 ohm .
The amp does not need to have volume control .
You could use fixed atenuators -10db at the Touch outputs then use the Touch's own volume control .
But preferable the amp has some kind of gain control , this is sadly uncommon in consumer amps but as you already ok with pro speakers :) ( control 1 is a pro speaker ) the utilitarian design of prosumer stuff is not a problem .
Would not the local music store ( not the hifi store ) have some sort of cheaper prosumer amp for hobby musicians that sports gain controlls ( usually at the back ,they are meant to be set once ).

Mnyb
2013-02-16, 01:17
Well I never! The thing sounds great (punchy sound with lots of stereo separation) and is considerably louder than the 50watt rms convention Yamaha amp I had used previously.

I've never been one to subscribe to amps making a huge difference to sound quality. But, (as with class a valve amps) this one did make a noticeable difference.

It can actually be the distortion that makes it be perceived as louder and that it would work as natural compressor ( have your own loudness war ) .

Many people actually likes the sound of class d amps ,but I thinks it s due to the fact that they have an audible sonic signature and given the specs it will be heard all the time , so I'm not surprised that these amps makes a difference .
Output impedance is usually a bit high to so bass can be a bit fatter ( really less control poor impulse response ) and sometimes treble anomalies ( very speaker dependent it could roll of or peak ).

I'm just a bit sceptical as usual , no offence and given the price there really is nothing to argue about . I have not dissected my cheaper powered speakers but I'll gues I'll actually enjoy similar amps inside them.

Julf
2013-02-16, 02:51
Many people actually likes the sound of class d amps ,but I thinks it s due to the fact that they have an audible sonic signature and given the specs it will be heard all the time , so I'm not surprised that these amps makes a difference .
Output impedance is usually a bit high to so bass can be a bit fatter ( really less control poor impulse response ) and sometimes treble anomalies ( very speaker dependent it could roll of or peak ).

Let's not paint all class D amps with the same broad brush...

ModelCitizen
2013-02-16, 03:08
Audiophilia. It's a strange thing. Many strive for the perfect uncoloured sound... but its my experience that the perfect uncoloured sound can be dead and emotionless (for me the Transporter fitted this description exactly). Naim stuff definitely colours the music but boy, does it sound good (OK, not their speakers). Class A valve amps also colour the audio but they generally sound fantastic (my antique Quad IIs do anyway). This class t amp may well colour the music.... but it also sounds great. BTW. I do run it with 4 ohm impedance speakers (I should have mentioned this, sorry).

:-)

Mnyb
2013-02-16, 03:31
Let's not paint all class D amps with the same broad brush...

I know ;) my generalisation is about the typical chip amps of the net + some others . There are exceptions .

NAD is for example building a completely different beast , they are aware of the impedance issue and have settings for the treble behaiuvor , NAD actually managed to get the LF impedance suitable low so it won't be a matter there .
But this have size and price outside of what op wants .

There is also some extremely well performing French amp ( sorry Alzheimer's ligth today ) that rivals traditional amp performance.

A 5w amp is a 5w amp , I do not buy into that some kind of watts are different than others , however the overdrive behaviour can be more acceptable with some solutions .

But some generalisation is valid most class d performe worse than a traditional amp .
That has nothing to do with the Technology as shown by NAD but rather the applications small and efficient and often also cheap.
And it does not help that sometimes some brands try to sell this a high end to just beefier ps and nice cases but still just chip amps.

castalla
2013-02-16, 03:36
I did the same thing and ended up buying this extremely small class d amp. Its a real beauty. Great sound and lots of welly. Fantastic value at 40 from eBay or Amazon.

Mini Audio Amplifier Muse M50 TPA3123 T-Amp 50W RMS

I use one of these too - excellent .... running 24/7 for over a year now.

GRC
2013-02-16, 04:01
The Muse suggestion is really a variant of my Topping TP-20 MK 2 (see my original post). Realistically around 10W per channel into 8 ohms without excessive distortion. Nice sound but still looking for more grunt. T-class seems to top out (s'cuse pun) at the TP-60 which looks like around 30W without distortion (rated at 50W into 8 ohms BUT 10% THD).

My Control Ones are not the Pro Version; the latter are 4 ohm nominal, the "domestic" version is 8 ohms, so we get a little less current out of the amp.

Any other thoughts folks? Please note budget (150 sterling / 175 euros / $230 US dollars).

Julf
2013-02-16, 04:43
I know ;) my generalisation is about the typical chip amps of the net + some others . There are exceptions.

I know what you mean - just had to pitch in. My main system uses 400W class D amp modules from Hypex. Output impedance 1 milliohm :)


A 5w amp is a 5w amp , I do not buy into that some kind of watts are different than others , however the overdrive behaviour can be more acceptable with some solutions .

I guess tube amps are the best example of this...