El34 to 6V6 conversion

[didi]

HI ALL!
I have a JCM900. i would like to convert the stock EL34's to 6V6's
I wanna do this in order to bring down the power output a bit. I suppose i would have to set the impedance selector switch one down? ANYWAY, Does anyone have a procedure do this? Any help will be much appreciated!!

[olddawg]

HI ALL!
I have a JCM900. i would like to convert the stock EL34's to 6V6's
I wanna do this in order to bring down the power output a bit. I suppose i would have to set the impedance selector switch one down? ANYWAY, Does anyone have a procedure do this? Any help will be much appreciated!!

Yellow Jacket adapters?

[porge]

I've done a similar conversion with my Hiwatt, and it was as simple as re-biasing. I set them up for about 10w. Very pleased with the results, and it might work with your Marshall, but I'm not so sure. Some important caveats:

Use JJ 6V6's - they can withstand the abuse.
Your plate voltage needs to be within the range a 6V6 will take. (The Hiwatt was 470 - I guess the marshall is much higher)
Expect lower tube life expectancy.


When I was told aout this conversion, I was told If using an 8 ohm speaker load, set the output impedance for 4 ohm.