Well, the OP is asking for it.
He actually read and disregarded the Forum´s description:
Not sure why Moderators have not ALREADY moved this misplaced Thread to the proper Forum. 🙄
The ECC40 is the only small signal double triode I know of which had a complete set of specs and schematics for audio (flea) power output.
http://frank.yueksel.org/sheets/046/e/ECC40.pdf
It has 1.5W dissipation per plate but also a much beefier 6.3v/0.6A heater than a 12AX7 allowing 10mA average plate current.
(a similar but even more powerful small signal tube could be the sovjet 6n1p, 2.2W/plate)
What did they get from an ECC40 then ?
In single ended, one plate output: 280mW @ 8.5% THD, 6mA plate, into 15kohm load
In push-pull, 520mW @ 1% THD, 2x5.6mA plates, into 30kohm p-p load.
Those data sheet proposals were intended for outputs in small radios, but even on radiomuseum.org I could not find any example of such use of the ECC40 other than pre-amp, phase inverter, or even rf application in an early FM converter.
http://frank.yueksel.org/sheets/046/e/ECC40.pdf
It has 1.5W dissipation per plate but also a much beefier 6.3v/0.6A heater than a 12AX7 allowing 10mA average plate current.
(a similar but even more powerful small signal tube could be the sovjet 6n1p, 2.2W/plate)
What did they get from an ECC40 then ?
In single ended, one plate output: 280mW @ 8.5% THD, 6mA plate, into 15kohm load
In push-pull, 520mW @ 1% THD, 2x5.6mA plates, into 30kohm p-p load.
Those data sheet proposals were intended for outputs in small radios, but even on radiomuseum.org I could not find any example of such use of the ECC40 other than pre-amp, phase inverter, or even rf application in an early FM converter.
With change of bias the 12BH7 could be used in circuits similar to the ECC40. And easier to find on this side of the Atlantic.🙂
Yes, exactly. That's what commercial flea power guitar amps look like: typically a 12AX7 front end and something like a 12AU7 or other lowish Rp dual triode PP power stage because you need a tube in current production for commercial volume.
If I were to attempt a guitar spud amp, I would use something like a 6T10. Very difficult to get enough sensitivity needed for a guitar amp in 1 tube section other than a pentode front end.