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RE: How To Bias A Fairchild 255a

Ok
You pull the bottom off and and underneath you will see the bias pot mounted on a little bracket off to the right.You basically put your meter on pin 5 of of the EL34 tube and adjust that pit until you get minus 33vdc.
The other pot is an AC balance and unless you have a signal generator and a scope,all you can do is set that pot at the center of rotation.I have a pair of 255s and you can also run 6L6s in these amps and the output trafos are 6.6k which is ideal for a 6L6.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken



Edits: 10/02/16

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