Home Cable Asylum

Interconnects, speaker wire, power cords. Ask the Cable Guys.

Power cords: what about digital?

Hi folks,

I'm fairly new to audio, and to this board, though I've been lurking for a while, and have posted from time to time. This discussion about power cords--a subject I've been interested in for a while--drew me out of my shell.

A while back I did some of the same analysis presented by audioengr, and convinced myself that voltage drop could, indeed, be significantly reduced with the use of low-impedence power cords. Then I read an article--and verified this for myself--that claimed that the biggest effect on sound is often with relatively low-power devices: dacs, cd players, etc. Sources. So what gives?

I've got a physics PhD, which gives me enough of a scientific background to at least know when I'm sure of something or merely speculating. Here, I'm just speculating. But it seems to me that power cords must affect sound in two distinct ways. One is the voltage drop effect, eloquently described by audioengr. But there's another, I think, and it's almost the opposite effect: digital devices create high-frequency noise, which is SUPPRESSED by inductance, not enhanced by it. Even with amplifiers, IMO, the biggest effect may well be (remember: I'm speculating) noise created by very fast, very intense current spikes (that "I" in audioengr analysis can get much larger than you might expect; that is, currents during that re-charging phase can far exceed rms values). These spikes cause voltage drops, surely, but they also radiate nastily. High inductance may cause voltage sag, but it suppresses these radiated nasties (and the digital ones, which ought to be less intense, but more numerous) which is a GOOD thing. If voltage sag were the only problem, some of the technologies used by amplifier designers to good effect--like baluns on the ac line (think PS Audio) don't make any sense. Those things make recharging those PS caps SLOWER, and INCREASE voltage sag. Yet they improve the sound. Why? Just speculating, but it's probably because they effectively reduce the bandwidth, attenuating some high-frequency noise?

Stands to reason, then, that there's an optimum inductance level--which isn't zero--for a power line--and that it's different for different components (CD players would require a different cord than an amplifier for optimum performance)...possibly even for different houses.

Now how do sources of noise that occur way, way above audible frequencies effect what we here? I've got some thoughts, but that's a subject for a different post.

Cheers,
Jim


This post is made possible by the generous support of people like you and our sponsors:
  Schiit Audio  


Follow Ups Full Thread
Follow Ups


You can not post to an archived thread.