audioray wrote:i was re-biasing sed el34 tubes and the left tube ran away. now i have no bias adj. could it be a resistor problem.
Hi Audioray,
To confirm that the bias is working, test the bias voltage at the socket side of R17 and R18 (these are the 1K grid stoppers). Without the secondaries connected, you should be able to verify these and smooth operation of your adj pots. If all this looks good, then look at your left octal socket. Unfortunately, the currently available ceramic PCB ones are not the greatest, and see if pin 5 (the grid pin) is a little dodgy. Also, if the plate connection at pin 3 was dodgy, your screen would go thermal as well. Basically look to see if they are too wide to make good contact with the tube base pin.
Shannon