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    Building, troubleshooting and testing of these amplifiers should only be
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suggestions for a rectifier


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?