Tired replacing the caps on the 6sl7 bias board and got almost half the volume in the right channel as the left. And I got an awful squeal when I put it into ultra linear mode in the left channel, The left channel's gain is so powerful and barely anything is coming out of the right channel. So, I switched the caps back to the original willsenton caps, and the same symptoms occurred; almost no right channel and a very powerful left channel. And the same squeal in the left channel. I'm wondering if I have some stray solder that splashed or a grounding problem or a bad resistor? I've tried everything I know. What would cause a high pitched shriek in one channel when not in triode mode? Transformer possibly? The local electronics shop tried to fix it, said they fixed it, said it was a loose pin socket, but the amp does the same it for when it left my house before being taken to the shop. Any ideas about this folks? I appreciate any help you might offer.