AUDIO RESEARCH D-76A

This is a job foooooor -- Hifigeek!! Or, you can call ARC and ask for Calvin. He's a great guy and I always found him extremely helpful.

Good luck.

What is the V number of that 12AX7 tube and I will investigate it for you.

I believe this are the original RCA tubes unfortunately most of the white numbers or letters are erased. all I can find are the red letters/numbers that says RCA afc 12ax7/ecc83. how ever I tried other four tungsol 12ax7 with no improvement. I just fund other symtom. Iv'd been running the amp for at least
3 hours when all of a sudden the right channel made a crackling sound. sense
that the right channel volume went down. until now I'm trying to figure it out. the left channel is 80% louder than the right channel. I will appreciate any advice I can get. thank you very much.
Art

Thanks Bifwynne, I will give him a call at ARC.

Torogi, if you really want to keep the amp, I strongly recommend at this point that you send it back to ARC for evaluation and repair. It is well known that ARC fixes everything they ever sold. I'm not an electronics techie, so I can't say whether your problems will be costly or not to fix. Who knows, maybe some old passives (e.g., caps or resisters) are bad. I believe that the D-76A was built in the mid-70s, so it could be 35 years old by now. Perhaps Hifigeek can weigh in if he has any ideas, especially what could be wrong and how much to fix. Good luck.