How do the half-power and Class A modes in the 395 work?

[Whoopysnorp]

Lately I have been running my Simul 395 with the half-power mode engaged on both tracks plus the Class A mode engaged on track 2 (that's for my leads). The manual seems to indicate that Class A mode shuts off the class A/B pair of tubes and just runs the 30 watt class A pair (or more accurately the pair running in triode). What, then, does the half-power mode do, technically? I've heard that in some Mesa power amps it just affects the 12AX7 driver tubes.

By the way, even with both power reduction options engaged, my leads are still REALLY REALLY LOUD.

 

[disassembled]

I've heard that in some Mesa power amps it just affects the 12AX7 driver tubes.

By the way, even with both power reduction options engaged, my leads are still REALLY REALLY LOUD.

You are correct. It only affects the Phase inverter tubes.

Tube amps, regardless of wattage, are loud and it's their nature. If you want a quiet amp you need something like 1/4 watt.


Greg