Tube Question....6V6 and 6L6

[toneman335]

Can a amp that runs with 6L6 also run with 6V6 tubes?

[John Phillips]

Sometimes.

Don't just try plugging them in.

You will need at the least a rebias (probably more than adjusting the trimmer will give you), and it's very possible that the voltages will be too high to safely run 6V6s as well. It will also cause an impedance mismatch which will stress the tubes more heavily.

[rooster]

On the SE ones I build, I use a switchable cathode resistor in parallel with the main cathode resistor, and the impedence selector is marked for the correct settings for both 6V6 and 6L6. I preferred not to take chances. I think if you were to do this on a "mainstream" amp, it would depend on the durability of the OT's, and it wouldn't hurt to tweak the bias or cathode resistor (depending on whether it's fixed/cathode bias).

My opinions, anyway.

rooster.