bias resistor change from 33k to 22k to increase the bias, bias hotter to achive better tone IMO..
increase the bias by reducing negative supply to grid(pin 5) from -40v to about -35v..
plate voltage (pin 3) - 460 v (all 4 tubes)
S.grid voltage (pin4)- 450v (all 4 tubes)
- bias ~ -35v
change all coupling caps for preamp and trem chatode ,change all filter caps due to old one already burst out...