Single-end Power amp with tubes

[Progg70]

I’m looking for a tube project, a power amp. I have in mind a single-end with no capacitors or transformers on the output. Perhaps a hybrid with bipolar transistors on the current side… Is there some treads her on the forum or some one else you can recommend.

Regard

Progg70

[nafanja]

Wy You would like to make transistor in output.
Transformers and other economy?

[Progg70]

Performans...performans

[kevinkr]

I've generally found the few hybrids I have built or repaired to be more fragile and inferior in sound quality to a really well executed SE or PP amplifier with a good output transformer. Mosfets are very useful in arrangements such as tubelabs powerdrive circuit, and as voltage regulators. Personally I have not met a hybrid I liked much.

Direct coupling mosfet output stages to tube driver stages is problematic, servo circuitry may be required or some other means of assuring very good dc stability will be required and the whole affair will be complex. A direct coupled SE hybrid will require very high standing dissipation in the output stage for any reasonable sort of output power and massive heatsinks. (Figure 4 - 5X the maximum output power as a guideline.)

I highly recommend one of tubelab's boards like the SimpleSE or Tubelab SE as a good first tube amplifier project. Performance will only be limited by the quality of the parts you choose, and importantly it will work.