Blind listening - TT3.0, HWmods and Teddy Pardo PSU

[Willakan]

Yup, that's correct.
Was a bit of a surprise that one, didn't think it would be that easy to hear.

Surprise?! Surprise!! The Touch's jitter is 300ps peak
Back to the test: both on max. volume presumably?

[NoRoDa]

Surprise?! Surprise!! The Touch's jitter is 300ps peak
Back to the test: both on max. volume presumably?

Don't know how the jitter relates to the PSU?


Yup, of course, both locked on max volume.

[Willakan]

Don't know how the jitter relates to the PSU?


Yup, of course, both locked on max volume.

The issue isn't so much that, rather that such levels of jitter are extremely low: far, far below even the most conservative of reported audibility thresholds. When the one with the better power supply is "clearly" better under blind conditions and it's a digital connection, it seems a tad strange, to say the least.

[mlsstl]

The issue isn't so much that, rather that such levels of jitter are extremely low: far, far below even the most conservative of reported audibility thresholds. When the one with the better power supply is "clearly" better under blind conditions and it's a digital connection, it seems a tad strange, to say the least.

Two considerations. First, what some call "blind" conditions can still leave a lot of room for subjective intrusions into the results. Well-done blind testing is hard work with lots of opportunities for corner-cutting.

Second, there are a lot of issues in audio other than just jitter. That seems to have become a catch-all term for placing blame. If there is a sound quality difference with the power supply used, it may be nothing more than RFI contaminating an analog stage and have zero connection with the digital aspect of the playback.

[NoRoDa]

Two considerations. First, what some call "blind" conditions can still leave a lot of room for subjective intrusions into the results. Well-done blind testing is hard work with lots of opportunities for corner-cutting.

Second, there are a lot of issues in audio other than just jitter. That seems to have become a catch-all term for placing blame. If there is a sound quality difference with the power supply used, it may be nothing more than RFI contaminating an analog stage and have zero connection with the digital aspect of the playback.

Yup

Our "test" was nothing more than listening blind and trying to tell one from the other.
No proof.

I agree that this (possible) difference with the PSU has to do with noise more than with the digital playback itself.

Regards

[Mnyb]

Yup

Our "test" was nothing more than listening blind and trying to tell one from the other.
No proof.

I agree that this (possible) difference with the PSU has to do with noise more than with the digital playback itself.

Regards

PSU could actually influence other parts of your hifi it is not necesarily the squeezebox that gets improved

[Willakan]

PSU could actually influence other parts of your hifi it is not necesarily the squeezebox that gets improved

I've heard this a lot: I'm really not that convinced. For example, I have an O2 headphone amp: it's prettymuch a cheapskate objectivist's wire with gain for headphones. The power supply is simple and elegant, mainly consisting of smoothing caps and a couple of generic regulators.

You can conduct an interesting test involving pulling the power cord out of the back, with the amp on and headphones plugged in. It'll immediately switch to an internal pair of batteries, causing a significant voltage fluctuation on both rails (12V to below 9V). No noise is produced in the headphones. Beyond the anecdote, the measurements reveal that the equipment doesn't really give too much of a crap about the power it's given. The power supply does a pretty good job, and the exemplary PSRR of a handful of cheap opamps does the rest.

I really can't see this idea of mains contamination ever manifesting itself as something that might conceivably ever be audible: likely not even measurable in many cases, especially with the trend in hi-fi to overengineer the power supply for marketing kudos...

I suppose contamination via the coax connection would be marginally more plausible, but again I'm skeptical: perhaps a test could be done with an optical cable? Anyone else got 2 squeezeboxes and some free time ?

[Mnyb]

It is a remote possibility ,not the most likely one , a couple of years ago some member did extensive ADM measurements with the SB3 and there was never any difference in the output with expensive PSU vs the original , so I offered it as a remote possibility , there is of course a handfull more likely reason why people hear differences as in most audiophile tweaks .
Unlikely but not entirely impossible , that was what I meant.

Personally i don't think my hifi is affected by PSU noise from other sources ( se signature ) as they all are switch mode anyway except the speakers

But the funny thing with hifi is that much of the really expensive esoterica can be designed not by good engineering principles but for some other concerns like some silver or tube fetisch , without feedback and almost no rejection of PSU noise ?

Sane design as you say should not be affected very much , but many audiophile products are not sane design , I expect your samsung DVD to be better !

The funny part is that if you have hifi that truly expose such a difference it is then "resolving" :P

[NoRoDa]

Instead of all that thinking, what about trying?
It can be very revealing, at least it was for me.

I can't explain why we were able to hear a difference between the stock and the Teddy PSU.
But at least the products in the system we listened to are "sane" components.

The few hours spent listening has given me peace of mind.
I rest assured that the SBT is a digital source good enough for me.
There are plenty of other aspects of the system to focus on.

Best regards

[Mnyb]

Instead of all that thinking, what about trying?
It can be very revealing, at least it was for me.

I can't explain why we were able to hear a difference between the stock and the Teddy PSU.
But at least the products in the system we listened to are "sane" components.

The few hours spent listening has given me peace of mind.
I rest assured that the SBT is a digital source good enough for me.
There are plenty of other aspects of the system to focus on.

Best regards

I have a CIA linear PSU left over from my SB3 days that now power the Touch , I can not recall or remember any great differences with the SB3 and I just dropped in the Touchs as replacement .
So I haven't compared but as my system is today it does not show any differences between reasonably built digital sources ( almost any source you can buy ) My meridianG98 sound the same as the Touch on CD material etc .
So not trying more third party PSU's with a digital source component is not giving me sleepless nights, I would call it a waste of time .

But your advice id a good one , audiophiles spent far to much time tweaking the probably least tweakable part of their whole hifi system the digital source .
(what they really do is tweaking the most tweakable part, their brain ,but they would never admit that )