Fender Twin on the bench with bad hiss.

[bbirling]

I have fender twin in for service that has a bad hiss. With V4 or V5 pulled the hiss is gone. So far I have tried new tubes and changed out Plate resistor on V5. Any help would be appreciated. I have to link to the schematic since it's to big to post.

http://support.fender.com/schematics/guitar_amplifiers/Twin-Amp_schematic.pdf
Bruce

[EL34]

Sounds like you need to do a service on the amp
Servicing Fender amps