Ckt for feedback

[rutledj]

Well, I finally found the problem with the tremolo. Removed the wire going from the footswitch to the oscillator ckt (used to kill the tremolo) and it started working. Replaced it with a shielded wire and all is good.

My only question now is what is the safe operating range for the power tubes. With the bias set at 34ma, the intensity knob will take it up to 50ma at full intensity. Does anyone know the "normal" range?

Thanks,
Rut

[rutledj]

I've been quite happy with the sound of this amp but I still have issues with the PT getting hot. I put an amp meters in series the the B+ (from standby switch) and the amp pulls about 150 - 200 ma with spikes up to 275 when cranked. The 6.3 is supplying 2 6l6's and 5 12axxx tubes.

Then Hammond 372JX is rated at 250ma and 8A on the 6.3. The xformer gets too hot too touch after about 15 min of moderate level playing (vol around 10-11).

The amp sounds great, reverb works great, tremolo works great. 6L6's are biased around 34ma (as read via a 1 ohm resistor in series with both tube cathodes). That is very cold by my calculations. I'm not using the 5v windings and have them taped up.

This is an international version and I have the Blue and Black tied together and the Brown and white tied together on the primary.

Can anyone offer some suggestions on what else I can check on this thing? Should transformers ever run this hot?

Thanks,
Rut

[jjman]

I'm guessing a bad filter cap somewhere. The ammeter, if accurate, is showing much more current that can be explained by 2 6L6s.

[rutledj]

What would you expect the current draw to be for the 2 6l6's and 5 12ax tubes?