Wolcotts - who can troubleshoot/service them?

I thought I was going to get a schematic to give to my tube tech (30 yrs McIntosh Labs) but it never came - asked for it two years ago!

Symptoms - original Russian output tubes are blowing. Replacement Chinese EL34Hs recommended by factory rep bias up but I have no sound.

Should I go back to new original Russian tubes?

None of the components (resistors) are fried.

Ivanj, the title of your thread says Wolcott, is that the amp that's going through tubes and no sound?

What factory rep recommended the Chinese tubes? Are you speaking to a tube rep or someone from Wolcott?