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DC Power Cables - Effects on SQ

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I suspect DC power cables might have an effect on SQ.  I don't know and have never measured one, nor have I conducted any blinded listening tests.

 

If you have done either - or just have an informed opinion on the matter, this is your thread.

 

Remember NO AC power cable discussion - there is another thread for that.

 

I further suspect that the most likely type of unit - if such SQ effects occur - would be at a DAC.  Wall wart power supplies are often placed near an AC outlet or plugged directly in, and a DC cable then extends a couple of feet (or a metre) to the DAC itself.

 

The DC cable may often run near noisy devices, and there is no transformer between it and the processing circuits in the DAC.


"The overwhelming majority [of audiophiles] have very little knowledge, if any, about the most basic principles and operating characteristics of audio equipment. They often base their purchasing decisions on hearsay, and the preaching of media sages. Unfortunately, because of commercial considerations, much information is rooted in increasing revenue, not in assisting the audiophile. It seems as if the only requirements for becoming an "authority" in the world of audio is a keyboard."

-- Bruce Rozenblit of Transcendent Sound

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what's in the final DC supply ?  any transformers or other components that might or would remove noise?

 

BTW, in the OP I forgot to mention that Ghent makes inexpensive DC cables for those interested in trying new things


"The overwhelming majority [of audiophiles] have very little knowledge, if any, about the most basic principles and operating characteristics of audio equipment. They often base their purchasing decisions on hearsay, and the preaching of media sages. Unfortunately, because of commercial considerations, much information is rooted in increasing revenue, not in assisting the audiophile. It seems as if the only requirements for becoming an "authority" in the world of audio is a keyboard."

-- Bruce Rozenblit of Transcendent Sound

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47 minutes ago, Ralf11 said:

what's in the final DC supply ?  any transformers or other components that might or would remove noise?

It's the voltage regulator circuit's job. That's what does the real work of both filtering incoming noise and all the noise generated by the product's circuits.

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but won't a Vreg introduce noise by its operation?

 

(admittedly, I have not wired up one since the early '80s...)


"The overwhelming majority [of audiophiles] have very little knowledge, if any, about the most basic principles and operating characteristics of audio equipment. They often base their purchasing decisions on hearsay, and the preaching of media sages. Unfortunately, because of commercial considerations, much information is rooted in increasing revenue, not in assisting the audiophile. It seems as if the only requirements for becoming an "authority" in the world of audio is a keyboard."

-- Bruce Rozenblit of Transcendent Sound

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4 hours ago, Speedskater said:

Only with poorly designed products.

A skilled circuit designer anticipates less than perfect DC from an external basic supply. The final DC supply is inside the product.

 Nevertheless, many members have reported worthwhile improvements when using the techniques described by E.E. John Swenson in this thread.

 


"If you can't hear the difference between an original CD and a copy of your CD,

you might as well give up your career as a tester. The difference between a reconstituted FLAC and full size WAV is much less than that, but it does exist. - Cookie Marenco"

 

PROFILE UPDATED 18-06-2019

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Just now, mansr said:

Another thread sanded.

 

The information from John's thread is completely on topic , and many members have reported a great deal of success when using the information that he has supplied.

 Note also that the thread also has 1185 replies, perhaps because you were unable to disrupt it ? 


"If you can't hear the difference between an original CD and a copy of your CD,

you might as well give up your career as a tester. The difference between a reconstituted FLAC and full size WAV is much less than that, but it does exist. - Cookie Marenco"

 

PROFILE UPDATED 18-06-2019

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I agree Sandy's post is on topic here, if a bit overly accepting of anecdotal reports.


"The overwhelming majority [of audiophiles] have very little knowledge, if any, about the most basic principles and operating characteristics of audio equipment. They often base their purchasing decisions on hearsay, and the preaching of media sages. Unfortunately, because of commercial considerations, much information is rooted in increasing revenue, not in assisting the audiophile. It seems as if the only requirements for becoming an "authority" in the world of audio is a keyboard."

-- Bruce Rozenblit of Transcendent Sound

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2 minutes ago, Ralf11 said:

I agree Sandy's post is on topic here, if a bit overly accepting of anecdotal reports.

 

And he used the phrase "many members" for extra style points...


“All of humanity's problems stem from man's inability to sit quietly in a room alone listening to music.”

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All too many 'improvements' using things like special power cables or any kind of interconnect (modulo certain kinds of speaker cables -- some very bad, some slightly better), these are due to EMI issues or as noted before -- working around exceptionally poor design.  It is a lot like the difference between the way that lossless file formats sound -- there are virtually ALWAYS uncontrolled variables that encourage misunderstanding what is really going on.

 

I do believe that electrical/electronic noise sources are grossly underestimated as the actual cause for sound differences attributed to interconnect/file formats.  (When I speak of 'noise', most of the time I am not speaking of Johnson or other VERY low level noise for power supplies -- I am speaking of things like noise from CPUS or other fast digital circuits that have current surges in the order of Amps and transition speeds of nsecs or less.) 

It really isn't being 'scientific' to blow off claims of unlikely behaviors -- but it is also unscientific to ignore careful experimental control.

WRT power supply quality -- less noise-creation, less noise-susceptability,less output impedance, less power-loss, better transient-recovery, more available current -- these and other things are all good.  A real-world design balances these attributes against cost, and purists seem to bias their goals away from the 'cost' and try to optimize the positive attributes.  Improving the positive attributes are 'good' things from a technical standpoint, but might not actually be helping the sound...  The 'fix' might actually have been improving the resistance of a cold solder joint (as a simple example.)  All of the heroic electronic 'shotgun improvements' might have overshadowed the actual circuit improvement.

 

The problem is -- do these 'improvements' make actual technical sound quality improvement, or is it a (respectfully) mental thing?  The correct way of doing things -- if the technical improvements cannot be clearly shown to provide better audio, then do an actual scientific, statistically meaningful comparison.  (ABX is a good kind of thing in this regard, for example.)

 

From very painful experience, I have found 'learning by feeling' is tantamount to acting like 'The Three Stooges' or 'herding cats'.   Gotta control those experiments so that next time a better targeted solution can be created  (maybe should really focus on the actual improvement(s), rather than a shotgun approach or a rather silly chase of many 'cats.')

 

John

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10 hours ago, John Dyson said:

- I am speaking of things like noise from CPUS or other fast digital circuits that have current surges in the order of Amps and transition speeds of nsecs or less.) 

 

https://blogs.mentor.com/hyperblog/blog/2015/06/02/simultaneously-switching-noise-an-overview/

Simultaneous switching noise, the digital power delivery system is designed to cater for this and the initial high dI/dt requirements, the on chip capacitance and local decoupling capacitors cater for the initial charge, then the on board reservoir caps. scattered about and finally the power supply as the power supply cannot handle the current requirements on its own.

We have to remember this noise is not stored in any digital files...

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16 hours ago, marce said:

Further to this, the main DC power that is distributed is often 12V or greater (15V is popular and sometime as high as 44V, generally below 50 then you don't have to worry about SELV requirements.)

If you use a cable for 12V it will pick up a certain amount of rf noise depending on the cable construction, the same cable carrying 3V will pick up the same noise, but with a far worse SNR. So if you are providing external DC, a main high voltage with local regulation as Mansr described is the best way in EMC terms. Providing multiple low voltage feeds via external cables increases the risk of cross-talk, rf pick up and other EMC issues. Then there is the cost and problem of filtering all these supplies when they enter the box being supplied. Filtering at the point of entry is the rule here.

I will dig into my notes and stuff on this, plenty off stuff from Henry Ott, Ralph Morrison, Keith Armstrong etc as well as many examples I can look at, there is a whole variety of filtering DC inputs and different components even active modules.

Sorry if you think its a bit OT but looking at the whole area of DC distribution will benefit the discussion. It could be the lack of proper filtering, bad wire layout etc. that does cause issues with some systems and noise pick up.

 

I'm looking forward to it.

 

If something puts noise 120 dB down we can likely move on...

 

 


"The overwhelming majority [of audiophiles] have very little knowledge, if any, about the most basic principles and operating characteristics of audio equipment. They often base their purchasing decisions on hearsay, and the preaching of media sages. Unfortunately, because of commercial considerations, much information is rooted in increasing revenue, not in assisting the audiophile. It seems as if the only requirements for becoming an "authority" in the world of audio is a keyboard."

-- Bruce Rozenblit of Transcendent Sound

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Let's keep on track with DC power supplies.

 

Sandy - if you start your own thread on noise in the disc or on an SD card, etc. then you will have control of it.


"The overwhelming majority [of audiophiles] have very little knowledge, if any, about the most basic principles and operating characteristics of audio equipment. They often base their purchasing decisions on hearsay, and the preaching of media sages. Unfortunately, because of commercial considerations, much information is rooted in increasing revenue, not in assisting the audiophile. It seems as if the only requirements for becoming an "authority" in the world of audio is a keyboard."

-- Bruce Rozenblit of Transcendent Sound

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I created a thread for this issue:

 

 

Please post there and do not derail this thread.


"The overwhelming majority [of audiophiles] have very little knowledge, if any, about the most basic principles and operating characteristics of audio equipment. They often base their purchasing decisions on hearsay, and the preaching of media sages. Unfortunately, because of commercial considerations, much information is rooted in increasing revenue, not in assisting the audiophile. It seems as if the only requirements for becoming an "authority" in the world of audio is a keyboard."

-- Bruce Rozenblit of Transcendent Sound

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3 minutes ago, sandyk said:

 I have already made it perfectly clear that I am not interested.

Go talk to yourself and Kumakuma in your new thread, and without favouritism remove the off topic replies in this thread that you created.

BYE !

Sandy - If you can't converse with people without losing your cool, you just can't hang around here. You are constantly offended. Feel free to say whatever you want in your own threads. 


Founder of Audiophile Style and Superphonica

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9 minutes ago, The Computer Audiophile said:

Sandy - If you can't converse with people without losing your cool, you just can't hang around here. You are constantly offended. Feel free to say whatever you want in your own threads. 

 Chris

 I have made it clear on several occasions that I no longer wish to continue this off topic discussion in Ralf11's thread..The OP already knew when he created the new thread that I was not interested in participating..


"If you can't hear the difference between an original CD and a copy of your CD,

you might as well give up your career as a tester. The difference between a reconstituted FLAC and full size WAV is much less than that, but it does exist. - Cookie Marenco"

 

PROFILE UPDATED 18-06-2019

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10 hours ago, The Computer Audiophile said:

Sandy - If you can't converse with people without losing your cool, you just can't hang around here. You are constantly offended. Feel free to say whatever you want in your own threads. 

Maybe a compulsory break from the forum would do him (or us) some good.

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