Seeking schematic Acoustic B-1 or similar

[Foggybottom]

Working on an Acoustic B-1 with low volume. I've worked on and built tube amps for audio but this is only my third guitar amp and third solid state amp. This one has a pair of 2SD424 transistors which is in a darlington pair configuration, or emitter follower? So far the power supply tests good, the transistors test good on my encore super cricket. One of what I believe to be a driver transistor needs to come out and be tested. It tests bad in circuit. Without a schematic I'm kind of flying blind, since SS is unfamiliar to me. If anyone knows of a B-1 schematic or a similar configuration to recommend I'd appreciate it.

Tim

 

[agedhorse]

I don’t think those were the stock transistors, and a pair of those transistors would be used as a darlington pair.

I’m not very familiar with that model, so I can’t provide much help.

 

[Foggybottom]

After some searching I did locate the schematic for a model B$ which is similar and the EQ board looks identical. One difference is that the board I have has a 1uf cap across the output pin to ground, right at the coax cable. What would the function of this cap be?

 

[agedhorse]

After some searching I did locate the schematic for a model B$ which is similar and the EQ board looks identical. One difference is that the board I have has a 1uf cap across the output pin to ground, right at the coax cable. What would the function of this cap be?

A 1uF cap would make it non-functional (IF it’s as you describe).

 

[Foggybottom]

As you surmised that cap does not go from output to ground but rather from the +15V power supply to ground.

I did find a bad 10uF 50 V electrolytic in the signal path by tracing the signal till it stopped just before the output of the board. Probably didn't need the schematic for that but nice to have it. The schematic is for the B4 model BTW. Thanks for your replies.