• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

suggestions for a rectifier

kevinkr

Administrator
Paid Member
You didn't mention whether this amplifier will use cathode or fixed bias, in the case of fixed bias you would be dissipating ~30W in each EL34 which is just a bit too high.. With cathode bias assuming an effective Vp of about 390V this would equate to about 27W - also imo "on the edge" - with modern tubes despite what the ratings say in triode connection I would not exceed 25W for reasonable tube life. (There's not much margin even at 25W.)
 
I'm using cathode bias with a 440R resistor at approximately -31V Vgk.
I simply followed the EL34 data sheet and approximated a Se configuration from the data given for the triode Connected PP which is rated at Va=400V, Ia=70mA with Rk=440R and Ra=5k. I've had a similar amp running for a year now with SS rectification and so far its not given me any problems......And am I not running the tubes at 24.4W since P=I^2*R = (70mA)^2 * 5k = 24.5W?