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Speaker DC output question

When I check the speaker outputs of my 2 gfa 565's, I get 2.0 mv on one amp and -6.0 mv on the other (using the positive and negative speaker terminals matched to the positive and negative probes on my meter) . When I switch the one that reads -6.0mv around the other way (positive probe on negative terminal and negative probe on positive terminal) I get a positive 6.0 mv. Is this normal? Thanks for any information. Doug



Re: Speaker DC output question

those dc values on the speaker outputs are ok, in my experience.
it's actually a little hard to adjust to exactly 0v DC
depending on the potentiometer.
when I've done that on other amps, usually only 1 or 2 or 3 degrees of turn will
jump around 0VDC, so 2mv and 6 mv aren't too bad and don't necessarily indicate
a bad problem with the amp.
also I never heard any "hum" on the Pioneer/Marantz/others amps I used to work on at
those values

IF you were around 100mv and could not adjust down, then sure, there's probably
still a problem ( check your differential input pair, maybe)

I think you're talking about Adcom amps. I'm a bit rusty :-)

Most amps I ever serviced had DC offset and idle current adjustments inside.
Do idle current adjustment per service manual, then adjust DC offset for 0v.
but my opinion is that your 2 mv and 6 mv readings are ok and not un-normal.
the polarity issue you mention is irrelevant - just a function of which probe
you put where.
anyway, that's my 2 cents. hope it helps.