Converting plexi clone to Cathode Bias

[jzucker]

Just wondering if it's worth trying to do this.

It's got a SS rectifier and I'm measuring around 450V on the plates. I'm willing to replace the OT if necessary.

[Zippy]

Hey Jack!

Quite a number of people have installed switchable bias and report little difference.

Check the Matchless Chieftain Reverb for a reference of a pair of EL34s running cathode bias.

http://schematicheaven.com/newamps/matc ... ieftan.pdf

[jaysg]

There's a Matchless Clubman also. I don't recall these being very successful amps for them. Dunno why.

[islandamp]

I,m thinking about doing a similiar thing to my Plexi clone, except I,m contemplating running 2-El34's in a parallel single ended cathode biased arrangement. I plan to modify the preamp a little and try to tame the harshness and power.

[jzucker]

Thanks for the advice. The situation is that I currently have a nice plexiclone and then ran into an opportunity to pickup an identical one very cheaply. So, I figured if I could get one to have some of the brilliance of the matchless type amps with less power, it might be worth having 2 of them. I'd probably tame the preamp a little by removing the 2nd .68 cap across the 820 ohm resistor, change the eq slope resistor back to 56k, change the treble cap, and a few other changes to mellow it out a bit. I guess I'm kind of looking for a poor man's Suhr Badger.