12000 series bias question
Posted: Fri Mar 31, 2017 11:23 am
Hi, going to bias my 12000 series, I believe I read to bias to 35 in full power mode, could anyone recommend the bias setting in variac setting thanks?
Generally bias around plate voltage rather than absolute figures
Stock 12 series output plate voltage is 490v
so 70% x 25w is 17.5watts
17.5/490 is between 35 and 36ma per tube
What do you measure plate voltage to be at you chosen variac setting (I guess 90v?)
work on that.