self split 12au7 (FF) into 10k OT?

[tedmich]

should it be ok to run a 10K OT on my firefly? what will it impact? I hate spending money on Hammond "universals" or anything else lately....

any way to load output to "see" higher impedance and just up volume to compensate? Free lunch anyone?

[zhyla]

If I remember right the Firefly is set up for a 22kOhm:8Ohm OT right? So you could get close with a 10kOhm:4Ohm OT and a 4 Ohm speaker. Er, no, that'd be stupid and backwards. You want to double your speaker impedance. That is your free lunch.

[tedmich]

so put a 16ohm load on the 8ohm tap? I have a 16ohm tap too...) ? its fryday...

[Steve Conner]

I've done it, it produces about 0.5 watt clean.

[andrew_k]

Or you could add another output valve and have 2 12au7 operating in parallel push-pull

[zhyla]

so put a 16ohm load on the 8ohm tap? I have a 16ohm tap too...) ? its fryday...

Think it thru such that the tubes see close to the right impedance reflected from your speaker. So if 8 ohms times 10k/8 gives you 10k and you need something more like 22k (off the top of my head here) then 16 ohms times 10k/8 is going to work fine.