6SN7 Parallel Power tube

[Cygnus X1]

I'm starting a new thread to try to get this straight.

Here is what I am doing...using a 6SN7 GTB as a single ended, cathode biased low wattage power tube for a guitar amp. No PI. Not push-pull.

Parallel, the plates,grid and cathodes are tied together.

I'm running B+ at 345 volts, the cathode is reading 10V.
I have a 1 ohm 10 watt resistor in line to measure the voltage drop across the cathode for bias, but either don't know how to read my meter, or it just isn't sensitive enough to give me a good reading. It registers "3" on the 200m scale (VDC).

The tube is running quite cool. It sounds best between 8V and 10V on the cathode.

Thoughts?

[Andy Le Blanc]

just measure volts ..... have the 1 ohm on the ground side of the bias resistor
it will give ma/mv..... move the decimal to the left to convert to A
IE: 50 ma/mv is .05 A.......... then its V x A = W
the design max for 6sn7 is 7.5W when both units are operating

If your meter is auto ranging is shouldnt be a problem but it might be on the
way out if its acting funky its pretty easy to cook one the max volts are low
on most of them....... some are actually too sensitive picking up interferance
or you might need new probes....

[Cygnus X1]

Thank you, Andy...

The meter is not autoranging (AW Sperry).
Things actually sound pretty good with the tube.
I surmise that "3" is actually 30mv.