Vibro Champ build question.

[StratTone]

Can a Stock MM OT handle a 6L6 and a GZ34/5AR4? I'm not looking for more power just a tone change. So I was thinking about changing the bias, adding a 6L6 and 5AR4. Is the OT safe?

[booj]

A 6L6 draws .9 amps filament current compared ot the 6V6's .45 amps. Since the two 12AX7's draw .3 amps apiece, you'd be going from .3 +.3 + .45 or 1.05 amp draw to 1.5 amp draw for the filaments. That's almost a 50% increase.
Without knowing what the actual spec is on the tranny, I'd say try it and see if it gets too hot to touch for 5 seconds after an hour or two. If it does it won't work reliably.
Also, the GZ34 will probably deliver more voltage to the output tube, as well as the tube itself drawing more current from the supply.
ALSO, the cathode cap fo the power tube will have to be increased to 800 ohms? 1k? to supply proper bias to the tube.

[guitician]

Since your B+ is still the same, it may go up a little, your probably OK with your OT.