• 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.

PP to parallel


Try this:

connect both systems in parallel, use half the cathode resistor value which is in now and double the cathode bypass cap. Connect the output coupling cap to the anodes and a plate resistor 5k/10W from anodes to B+.

Alternatively you can try just single systems: Disconnect the upper system in the SRPP stack, or better ground all unused elements. Leave the cathode R and C and use a 10k plate load resistor.

Best regards



2007-05-30 4:12 pm
Try if you like SE by moving the output cap to below the upper 330ohm. This way the lower triode will be loaded by, in the ballpark of, 20k. This if we assume Ri being just below 10k at this low Ia.

About parallelled 6922 halves I have no idea if it sounds good, haven´t tried. But you have the answer about how to do in Thomas post above. (Our posts crossed)
Last edited:
Could you check if I do well the schematic, picture:


  • parallel 6922.jpg
    parallel 6922.jpg
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