Power supply requirement for Touch?

[mlsstl]

So who are you guys to criticize me and other for hearning that PS make a difference? I think you guys have to work with your attitude.

I see precious little difference between your opening snipe and the "attitude" problem you accuse others of having.

And, since you started the thread, I think it is fair to say you set the tone of the discussion.

Basically your position seems to be that it is OK for you to be catty and snide about the issue but it isn't right that others use a similar tone if they happen to disagree with you. Just another variant of the "free speech for me but not for thee" theme that is ever popular.

It just gets back to the never-ending dispute between certain camps in the audiophile world.

I've tried different power supplies with my SB3 and found no difference I could detect. Guess that means my system or my ears "aren't resolving enough."

;-)

[baardbaard]

I give up - you win.

Now to something else - I contacted Paul Hynes this morning and ordered his SR3-05.
http://www.paulhynesdesign.com/index.html

"The SR3-05 can supply 5 volts at 3 amps. It is also my best power supply for the SB3/Touch for musical enjoyment"

For the rest off you - I will get back for a short review/comments.
It will take some time, the build schedule is currently 24 working days.

[h.rav]

^ do you have or can you find any measurements done that show a 'superior' power supply improves the Squeezebox' SQ?

[baardbaard]

^ do you have or can you find any measurements done that show a 'superior' power supply improves the Squeezebox' SQ?

paul@paulhynesdesign.com will be glad to tell you...

[h.rav]

^ I want to see an independent test, not from a manufacturer.

[baardbaard]

Contact Ben Duncan, at Ben Duncan Research
http://www.benduncanresearch.com/

BD-UK@dial.pipex.com

He wil be glad to help you out.

[iwannatouch]

I'm sure I'd hear a difference if I spent $300 for a power supply.

[Phil Leigh]

So who are you guys to criticize me and other for hearning that PS make a difference? I think you guys have to work with your attitude. I can’t se why my opening statement possible couldn’t have offended you when you read what other well regarded web sites write about this issue.


"We replace the noisy, switching power supply with a large, linear power supply.”
http://www.computeraudiophile.com/bo...uet-review.htm

”First, the stock switching power supply is woefully inadequate for the critical listening that we audiophiles do.”
http://www.enjoythemusic.com/magazin...squeezebox.htm

When I moved from the standard SMPS (that is supplied with the SB3) to my DIY linear PSU, I could clearly hear a difference in the sound, despite only using the SB3 as a digital transport.
http://www.tnt-audio.com/accessories/phsb3_psu_e.html

The mere fact that you just had to come back one more time on this tells its own story.

You said you were an engineer? - try some engineering then, instead of putting faith in dubious magazine articles and even more dubious internet links.

Prove your replacement supply improves the audio replay quality... or even that it changes it in a truly noticeable way.

Does Paul Hynes actually have a Touch and has he actually tested his regs with it? - I hope so because anyone claiming a blanket improvement over "SB3/Touch" as if they were similar had better have actually tested that. The two devices are very different - especially in terms of the areas that might be improved by the PSU!

As for Ben Duncan - someone whose work I have studied over the last 30 years - I doubt he would make such claims unless he actually had a Touch and had tested it.

Stop trolling and provide some FACTS.

[baardbaard]

Let’s look into some measurements with audible effect – from John Atkinson:

The Squeezebox's frequency response (fig.1) showed a slight shelving-down at low frequencies that might just be audible given the wide range covered. (this has nothing to do with SMPS).

Now to something that may be effected by the minuscule wall-wart.:

Fig.2 shows the spectrum of the Squeezebox's analog output analyzed with a swept 1/3-octave bandpass filter while it decoded dithered data representing a 1kHz tone at –90dBFS. The traces are free from both power-supply and harmonic-distortion spuriae and peak at –90dBFS, suggesting good DAC linearity. The right-channel trace has some energy peaks centered on 9kHz and 18kHz, but these are low in level. Both channels also have a small energy peak evident at 30Hz, and the overall noise floor is 10–20dB higher in the midrange and bass than with the best 16-bit playback devices.

Summarize:
…the Squeezebox measures very well. Its noise floor is higher than that of good CD players.

[Phil Leigh]

Let’s look into some measurements with audible effect – from John Atkinson:

The Squeezebox's frequency response (fig.1) showed a slight shelving-down at low frequencies that might just be audible given the wide range covered. (this has nothing to do with SMPS).

Now to something that may be effected by the minuscule wall-wart.:

Fig.2 shows the spectrum of the Squeezebox's analog output analyzed with a swept 1/3-octave bandpass filter while it decoded dithered data representing a 1kHz tone at –90dBFS. The traces are free from both power-supply and harmonic-distortion spuriae and peak at –90dBFS, suggesting good DAC linearity. The right-channel trace has some energy peaks centered on 9kHz and 18kHz, but these are low in level. Both channels also have a small energy peak evident at 30Hz, and the overall noise floor is 10–20dB higher in the midrange and bass than with the best 16-bit playback devices.

Summarize:
…the Squeezebox measures very well. Its noise floor is higher than that of good CD players.

Great.
The noise on the right-channel is likely to be related to the VFD, which is known to affect one channel more than the other. Some people can actually hear the VFD noise breaking through (with their amps at full blast).

If I am interpreting JA's graphs correctly, the average noise floor seems to be sitting between -105 to -110dB.

I'm not sure how that equates to "10–20dB higher in the midrange and bass than with the best 16-bit playback devices".

However, -100dB is quiet. You would have to have lots of gain and very sensitive speakers or very powerful amplifiers to be able to hear anything at that level.


If JA was to repeat his tests with a different PSU...

My tests show that the noise floor of the Touch is substantially below that of the SB3. In part this is explained by the absence of the VFD, but also by other circuit changes.

Direct null testing of the stock PSU vs a quiet linear and even with batteries on the SB3 show no differences above -90dB.

So it seems that the noise floor performance is being set by the SB3 itself not its supply.

I have been unable to measure any performance improvement simply by changing the PSU. I can't hear one either. I should point out that I did swap my SMPS for a linear some years ago but have since swapped it back as the SMPS uses a lot less electricity and I can't hear or measure any benefit.


With the Touch we are talking about a much lower internal noise floor (-20dB from memory) to begin with - and I still can't hear or measure any change in audio quality with different PSU's.