Push Pull 6550 Low Volume?

[oogabooga23]

I fixed up a Bell and Howell 16mm film projector to use as a guitar amplifier. It utilizes 1 7199, one half for the voltage amplifier and the other for the phase inverter, and 2 6550 tubes. I measured roughly 26 watts dissipation per tube (320 volts from plate to cathode and my bias probe measuring 80 mA per tube), yet the amp at max volume barely sounds loud. My single ended 6L6 amplifier with a 5751 tube sounds way louder. My question is, could it be because it only utilizes one gain stage that the volume seems low? If I drive it with a preamp pedal, it sounds much louder. I should also mention that I dropped the plate voltage from 480 to 350 volts since it was redplating, and this could have possibly caused the preamp voltage to drop as well? The schematic said for 400 volts on the plates, but the amplifier was redplating still at that voltage. I plan on going back into the amplifier and upping the plate voltage to 400 but increasing the cathode resistor to possibly stop redplating.

[sluckey]

Nothing wrong. It's not loud because it's just a power amp. You must have a guitar friendly preamp to obtain loud. Your preamp pedal proved that.

[oogabooga23]

Thank you, I couldn’t find a definite answer online, but now I know!