Trainwreck clone biasing

[populartsl]

Just got my ceriatone trainwreck express clone. I want to change the tubes from 6v6 to el34's.
What should the bias voltage be for the 6v6 and what bias voltage for the el34.
Whats the best way to set the bias with my multimeter and which scale do i set the multimeter.

Hope someone can help.

Ben

[v00d00blues79]

Well... I biased mine by setting the trim-pot to where i got -30v on Pin 5 of the output tube. I run mine with both EL34's and 6V6's and this will work for both.


Thanks,

Andy

[keithrick]

Same here. Thats the way Ken does it! I still checked to make sure I was within safe ranges. The tubes are run a little hot!

[v00d00blues79]

I run some NOS RCA 6V6's in mine and it runs pretty good with'em.


Andy

[populartsl]

Cheers guys

Ben

[arfy]

now I'm getting confused. I read in the TW pages that KF biases his amps so that there is -30 V at the grids, so far so good. But my Express clone was made with Toneslut transformers, etc, by me, it's a different amp although I've tried hard to follow the known design, and I'm biasing it to hit the typical 70% idle dissipation and the negative voltage at the grid winds up at about -32 V plus change to reach that dissipation level.
So did KF intend to run the power tubes hotter than normal and that's why he prescribes the -30 bias? I had been assuming that he tweaked the amps to hit the common 70% dissipation but maybe that wasn't his aim and I've missed the point.
Any comments? What are your amps showing as idle plate dissipation with -30 V bias voltage?