Need some foo fighting technical backup

[jez]

There is a thread on whether or not mains cables can make an audible difference to Hi-Fi equipment at the following url:
The mains cable poll - pink fish media
It's all been the usual audiophool stuff and opinions being vehemently made as usual. As an EE, and someone who does not like to see BS of a technical nature go unchallenged, I joined this with my viewpoint that mains cables cannot effect the performance of hi-fi and the whole industry making them are basically snake oil vendors....
However... someone who claims to also be an EE has joined the fray and says he has an AP-1 at his disposal with which he has made measurements proving that mains cables can make a difference... He is actually claiming improved THD figures when using the audiophool cable!
The whole thing is getting quite heated, as these things tend to, but at the moment there only the two of us with any technical credentials taking part... and we disagree in a big way!
It would be interesting if some of our more technical members here, maybe even some of the "big guns", would like to join in the "debate".... whichever way that takes it!
I would of course understand completely if no one wanted to lower themselves to mains cable debates But when someone is claiming to be able to prove it....

[pinkmouse]

This has been covered many times here, and I suspect most are very reluctant to get involved yet again...

[jez]

HOLD THE FRONT PAGE!!!

My colleague on the other site has discovered the cause of his experimental error and, on further testing, has found cables to make no difference. And he has been big enough to admit it.
We won't have to re-write the electronics text books after all!
Moderators please feel free to remove this thread.

[GloBug]

Thank goodness. Now I can get rid of that crystal nut-sack hanging from my power cord.

[ThorstenL]

Hi,

Originally Posted by jez

There is a thread on whether or not mains cables can make an audible difference to Hi-Fi equipment

This is trickey. Proof of audibility that is widely accepted is and above criticism requires work, funding and many volounteers.

Originally Posted by jez

However... someone who claims to also be an EE has joined the fray and says he has an AP-1 at his disposal with which he has made measurements proving that mains cables can make a difference... He is actually claiming improved THD figures when using the audiophool cable!

Well, I only use an AP-2 so it is not me and if the improvement is strictly THD (as opposed to THD & N) I suspect experimental error.

However mains (and other) cables with different electrical properties can produce measurable differences in terms of noisefloor and that beyond just simple hum & buzz related to the main mains frequency.

In fact, it takes major effort with isolation transformators, extra earthing, special low impedance ground interconnects etc. to even allow one to use the principle capabilities the AP-2 has in loop-back when a second device is connected and tested that is mains powered.

Depending on the DUT the broadband noise entering the device via the mains can be very measurable.

For example, our Lab has many fluorescent lights with electronic ballasts that throw so much noise into the mains that I have to turn them off to be able to get this spike out of the FFT and different mains cable can make differences to the height of this spike.

Ciao T