Digital, but not by the numbers

[twest820]

Originally Posted by marce

Curious as to how a well designed DC supply can alter the sound, it is DC after all.

Try here and here for intros on how amplifiers interact with linear supplies. (Caution: links contain numbers and graphs which may not be appropriate to bring back to this thread, not least because the calculations are for different design targets. )

[marce]

Cheers Twest820.
Maybe what I should have said is that for ultimate fidelity I belive that you have to design the PSU as part of the system, not a seperate entity.

[TNT]

Originally Posted by marce

Curious as to how a well designed DC supply can alter the sound, it is DC after all.

Well, it's the DC that becomes the signal, isn't it?

[marce]

Lets not go down that path, I have worked on numerous electronic systems over the years including instrumentation based analogue systems such as Daresbury in the past, and currently a 24bit 50 channel ADC based design. All systems have to have supplies, more often than not DC so dont try and patronise me over the DC becoming the signal, no the DEC is modulated in some way to become the signal. If you power supply is affecting sound quality then it is either badly designed or is the wrong supply for the amplicfication stage that follows.
Read my quote, "a well designed".
Instead of arguing over the supply of a supply wouldn't it be better to design the supply and the rest of the system as a whole.
Also I though this part of the discussion was over and we could move on to the digital side, wich should be interesting.

[DF96]

The danger for this thread is that some might see it as trying to 'go beyond' conventional good engineering, when the real problem is that conventional good engineering might not yet have been attained. Once attained, it might be found that there is no 'beyond' to go to.

If it addresses real issues, with real understanding, then it will be worthwhile.

[abraxalito]

I don't see any danger in people's false perceptions of this thread myself or I'd not have started it.

@marce - I agree, much better to consider the power supply an integral part of the whole system, not just bolt one on at the end. The aim is indeed a well engineered system, not just well designed. Well engineered to take into account best SQ for the price.

[Pano]

Originally Posted by abraxalito

Well engineered to take into account best SQ for the price.

I certainly know what works well for me and doesn't have the typical digital sound. The DC supply for the analog section of the DAC chip makes much more difference than I thought it would, so putting some effort there really does pay off.

[TNT]

Originally Posted by marce

... If you power supply is affecting sound quality then it is either badly designed or...

qed

[abraxalito]

Just recently found this (old) paper which tells the story of what happens when a digital system isn't engineered properly, that is holistically, taking into account end-user feedback, but rather by the numbers. The numbers in this case being a particular metric chosen to characterize the machine's safety. Here's the relevant paragraph from the pdf (which is long, but fascinating reading): http://sunnyday.mit.edu/papers/therac.pdf

[DF96]

That is a classic software malfunction story. I'm not sure what relevance it has to digital audio.