Help needed on Mullard EL34PP

[ed]

The tube socket did cross my mind while I was checking the amp with another friend. But we just test using a multimeter and conclude that its working. Maybe changing the socket may help.

Got some new caps and will desolder and resolder the components overs the week end. Will update on the results.

When you mentioned cathode caps are you referring to the EL34s cathodes??

Brgds,

Switched the tubes, switched the components, still have the same problem... Would it be the problem with tube sockets?

Check all the DC resistance at different points, like anode-gnd, cathode-gnd, grid-gnd (of course with power off and unplug the AC power cord) If possible, remove all those electrolytic caps and check with leakage. If not the tubes, the distortion problem seems like from the caps, most probably the cathode caps.

may be you can try to input a small signal in (from a signal generator, load with a resistor to output terminals) and check any voltage changes (anode, cathode and grid)

I have an experience with a defect 8 pins ceramic socket long time ago. Even it's new, problem solved after I changed the socket, may be you can try it in your last step. Hope you can solve the problems very soon...