"Mark D. Zacharias" wrote in message
...
The bias is set by soldering together or unsoldering specific adjacent
foil
pads near the bias transistors. No practical way of telling you which to
use
via these postings. For each bias transistor there is one pad pair which
is
soldered to increase bias, and one to decrease bias. If both were
soldered,
there would effectively be no change in bias.

There are surface-mount transistors which can be shorted emitter-base to
defeat the "blow" function. Assuming there is no other problems, the amp
would fire up OK after replacing the outputs and 220 ohm resistors.
The Blow line must measure less than 100mV under all conditions before it
is
safe to unsolder the surface-mount transistors mentioned above.

ALWAYS bleed off the power supplies - all 4 of them - before any soldering
etc. These supplies do not go down or bleed off when the power is removed,
not even when unplugged.

Post back if your still into doing this one, and I can get more info -
I've
done lots of these.

Mark Z.



Oh joy, if I'd known how much hassle this would be I wouldn't have ordered
parts, oh well. Now that I'm into it I may as well see if I can finish. So
let me get this straight, the "protection" circuit *intentionally* blows the
output transistors?! What the hell were they thinking??

Where are the 220 ohm resistors? I was looking casually for the usual
largish resistors but I didn't see them. What's the general procedure for
setting the bias? The only amps I've ever done it on I had a listing of
exactly what current to adjust for and a pot which made it easy. This is a
rather unusual amp, please fill me in with any info you can. Thanks!