On Tue, 25 May 2010 16:17:18 +0000, GregS wrote:

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.


Could serve dual purpose. Guessing is good, stimulates the mind. I could
go along with the arc noise. Snapping while it was on with a good jolt
could cause speaker protection to kick in or pop a midrange or tweeter.