In article , Meat Plow wrote:
On Tue, 25 May 2010 15:05:59 +0000, GregS wrote:

In article , Meat Plow
wrote:
On Tue, 25 May 2010 02:30:29 +0000, Paul G. wrote:

Probably a guess, but I suspect the mystery part is a high value
resistor as Phil stated. Its purpose is for "leaking" any DC static

And Paul G wins the contest!

Go claim your prize, a date with Phil Allison.

The resistor is there to protect the amplifier from static discharge.
Said static could build up while wiring up the speakers or even after
they are wired scooting them around on the carpet.

I think I have added resistors like that to my circuits. It can help but
is not foolproof. A static charge to the amplifier metal will occur
regardless of resistance to AC ground. It can help prevent transformer
arcover.

greg

Nothing is foolproof. My reference was strictly static discharge via
speaker wires. Since the resistor is not in the schematic from what I
understand, it must be a factory fitting after a trend was spotted in
warranty repairs. Maybe the output device is sensitive to ESD augmented
by the output circuit design.

I would go along with saying, it has nothing to do with output devices.
it will discharge a DC differential in the amps circuit vs AC ground. It
could do this and that, but could provide power off protection and transformer
arc protection. Pretty much guessing beyond this.
HV arc noise ? I had problems once with an 8 track capstan, had
to add a static drain wire.

greg