I'm trying to bias a 1992 VHT Pittbull Classic 100watt anyone help what should (mA) be set at? thanks for any help
I'm trying to bias a 1992 VHT Pittbull Classic 100watt anyone help what should (mA) be set at? thanks for any help
Last edited by 100watt; 09-05-2016 at 06:54 PM.
34ma per tube
Measure the anode to cathode voltage. Set the bias current so that the quiescent dissipated power for each tube is not higher than (rule of thumb) approximately 75% of the tube's rated power. An EL-34 is rated for 25 W. e.g. if the plate voltage is 450 V, you'd want about ((25 W * 0.75) / 450 V) = 42 mA per tube, or a total of 167 mA combined for all tubes. Likewise, if the plate voltage is 500 V, you'd want 37.5 mA per tube. I probably wouldn't go higher than 75% quiescent dissipation if you value the life of your tubes. Feel free to go lower, though.
Thanks very much for your help