[Table of Contents]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [ARSCLIST] Aren't recordings original sources?

Thanks, Bob.
There are at least two other problems I've dealt with as well.
I owned and operated one of the last analog pro studios in Northern California for a few years and was plagued with intermittent ghost hums and other ills. It wasn't until I put a large 1:1 isolation transformer between the pole and the main power feed that much of that went away.
Still there were some problems. We discovered, through the highly scientific hit-or-miss method, that ground for a rack is not necessarily ground for the power system. That there can be a potential voltage difference not only there, but difference in resistance depending on where the copper ground stakes for each separate circuit are placed in, well, the ground!
Once we discovered that some time, persistence and a good voltmeter banished the problems. Now all we had to deal with were any parallel voltage feeds to other, outside circuits and noisy client amplifiers. The iso transformer took care of the first, and individual attention, the second.
The point of all this is as I said before - one power cord will not make any appreciable difference in frequency response - including 60 cycle hum - for an individual unit in the chain, unless it is flawed (said flaw would include its being under-gauge for it's application).
Mal Rockwell


Bob Olhsson wrote:
-----Original Message-----
>From Tom Fine: "... do you think powerline fuzz and hash matter more, less
or none to modern gear that uses cheaper/lightweight and switching-type power supplies? I'd think the
old-school stuff wouldn't care, it was designed to operate on the principle of an over-spec'd power supply
providing a large reserve for peak-power demands after the conversion to DC. But some of these modern
devices -- including well-rated professional gear -- seem to have such flimsy power supplies, I
wonder if all this matters more in that world. Plus, there are arguments to be made about the
quality of internal power and the performance of digital devices, but again what is provided on the
gear may well be up to the job in the case of professional-grade equipment. Bottom line, I highly doubt
what sort of power cord you use as long as you're using properly-spec'd gauge wires, matters in any
of this..."

I've heard power cords make a surprising difference especially shielded vs.
non-shielded. Tying every neutral in an audio system together at one point
makes a bigger difference as does cleaning and tightening every single AC
connection all the way back to the power pole. Doing both in my experience
has reduced the effect of AC cords considerably.

You can ask anybody in the touring sound business and they'll talk your ear
off for an hour about the incompetent power supply and grounding design
found in most of the past 40 years worth of so-called "pro" audio gear and
there is no reason to expect consumer audio to be any better. When you
consider how little AC wiring has even been touched in a half century and
how poorly designed most gear is, it shouldn't be surprising that anything
that alters the frequency response of an audio grounding system may well be
audible due to different flavors of RFI. Obviously if you can hear anything
change, all flavors are wrong but those of us who hear this stuff aren't
lunatics and at least some of us are pretty happy with a heavy duty, well
shielded $20 power cord.

Bob Olhsson Audio Mastery, Nashville TN Mastering, Audio for Picture, Mix Evaluation and Quality Control Over 40 years making people sound better than they ever imagined! 615.385.8051 http://www.hyperback.com http://www.thewombforums.com

[Subject index] [Index for current month] [Table of Contents]