help with audio resesrch d76


Hi I just picked up a couple arc amps a d76 and a 90b both in mint condition. What one is the better of the 2 and what do they sell for. I'm getting rid of one or the other. Gary
tubesmore

Showing 3 responses by whitestar23

Hifigeek1,
I was wondering if you could answer a question I have, is the arc d-90b triod?
Thanks,
Whitestar23
Thanks Hifigeek,

that is exactly what I wanted to know. You have confirmed my suspicions my tech is a very good solder monkey.

I was talking having my sockets replaced in mine and he said that it was wired in triod. I asked if it was suppose to be he said according to the ARC schematic it was. I asked him to double check and he said he just confirmed it by re looking at schematic in the manual.

This made no sense to me that it could be triod with 80 watts output and that small of output transformers.
They dimensionally look the exact same to me as the Classic 60 outputs.
HIfigeek,
I meant the transformers from my d-90b look identical, at least external as the cl-60.

Would it not be as simple to run the d-90b in triod as

1. Remove the screen tap leads wires from pin 4 of the output tube sockets
2) Connect a 1 or 1/2 resistor from pin 3 to pin 4 (plate and screen) on each of the four output tubes
3) re bias
thanks and have a good one.