[ProAudio] AES on the west coast, was Re: Ampex/ProAudio List Dinner

[Bill Whitlock]

Corey and Steve (and others who might be interested), here is a link to one of my presentations in pdf format:
https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf
Cory, note the section on AC power and the example of just what you proposed.
Steve, note the explanation of how a balanced interface rejects noise - it has nothing whatsoever to do with equal and opposite signal swings.

Bill Whitlock
Whitlock Consulting
Ventura, CA


-----Original Message-----
From: Corey Bailey Audio Engineering <proaudio at baileyzone.net>
To: proaudio <proaudio at bach.pgm.com>
Sent: Mon, Nov 4, 2019 4:10 pm
Subject: Re: [ProAudio] AES on the west coast, was Re: Ampex/ProAudio List Dinner

 Jim Brown, Bill Whitlock & David Josephson: All great advice, For equipment that I want to be truly ground isolated, I use a driven stake (Grounding Rod) and avoid AC ground if at all possible (local electrical codes be damned!). Then, follow the advice of someone who's knowledgeable on the subject of proper grounding. (Like, any of the three mentioned above.) Cheers! Corey
  Corey Bailey Audio Engineering
www.baileyzone.net On 11/4/2019 10:18 AM, Jim Brown wrote:
  
On 11/3/2019 7:38 PM, David Josephson wrote: 
 
For instance as Jim Brown says, every conductor is an antenna. 
 
 
 My favorite quote on this topic is from Henry Ott, who in his lectures spoke of the hidden schematic lurking behind the ground symbol. Since my retirement, I've been devoting my energies to ham radio, teaching fundamentals to folks with a wide variety of technical backgrounds. No surprise, the Pin One Problem is a hot topic -- Neil Muncy repeatedly told me that it was the primary mechanism behind RFI, and work for a paper that David and I co-authored in 2003 proved it. Fast forward to today, Pin One in CATV and DSL systems is the cause of EGRESS of RF noise that pollutes the radio spectrum. 
 
 I do, however, strongly object to the phrase "ground loop," instead using Bill's excellent model showing the mechanism as a difference in potential chassis-to-chassis between interconnected equipment (or chassis to ground) t as the cause of shield current, whether that difference is created by IR drops in green wires or antenna action. The reason I so strongly object is the that solution, especially in small very local systems, is so often proper bonding, which visually creates a loop with signal conductor shields. I'm thinking here of a home entertainment system or a ham station. I use a drawing of Bill's model in my talks and on-sine tutorials. 
 
 I stopped teaching at trade shows several years ago because I was unwilling to participate in one held in Florida, in protest of the acquittal of that vigilante murder and the law that allowed it. 
 
 As to our conventions -- my interest has always been in the papers and workshops, and hanging out with colleagues. In retirement, I can no longer justify the cost of a convention that requires a hotel stay in an expensive city. 
 
 Henry Ott also did a great breakdown on the inductance of a wire as part of a loop. 
 
 Jim Brown 
 
 
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