Date:         Fri, 24 Oct 2008 14:33:35 -0500
Reply-To:     Association for Recorded Sound Discussion List
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From:         Scott Phillips <[log in to unmask]>
Subject:      Re: Aren't recordings original sources?
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	Interesting. When I worked for Sony, our department was
responsible for UL leakage testing of professional products, among other
things. If the leakage was caused by the equipment itself, it should
never have been approved for sale, or the equipment was defective. Cheap
power transformers and badly designed surge suppressors seem to be more
common than one would like, both with high leakage factors. Still, as I
remember any leakage current you could actually feel is far outside the
UL certification limits. 

	This does assume proper design with a polarized 2 prong plug,
or, of course, proper 3 prong grounding.  In more cases than I care to
say, I have found that the outlet that everything was plugged into was
wired incorrectly. Every single house I've ever lived in had at least
one wired wrong when I checked them all, or incorrect grounds / crossed
neutral wires. 
	I have no doubt at all that the effects of AC leakage currents
can produce audible changes beyond just making some noise. (Which would
be bad enough anyway.) As Clark might have pointed out, an inferior
power cord arrangement may increase leakage currents. He and I may not
agree on everything, but an outright cheesy power cord could have enough
reactance to couple leakage currents...

Scott

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of Don Cox
Sent: Thursday, October 23, 2008 3:09 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Aren't recordings original sources?

Hello Larry

On 21/10/08, Larry S Miller wrote:
>  I completely agree with your observation below about there being a
> audible difference depending upon electrical plug orientation (for
> two-pronged plugs.) On many units I was able to determine the "proper"
> orientation by running the back of my hand across the faceplate of a
> unit. If I felt a noticeable tingle, I'd reverse the plug and try
> again. Invariably, the one with the least tingle was the best
> sounding.

I agree with this, but I haven't had this experience with recent
equipment. 

>  Now, I will say that some other people seemed less able to detect
> this than I, but we did do some blind tests and I was consistently
> able to identify the same orientation on those units which had a
> perceptible difference. Some units seemed to have no difference,
> perhaps those were better designed.
> 

Regards
-- 
Don Cox
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