I have used my Roland AC60 amplifier with a condenser micro phone or dynamic Schertler pickup, in one channel, on the acoustic.
[its a 30+30 watt stereo amp]
the magnetic coil [stacked humbucker] pickup equipped 4 string electric mando,
on the same amp,
and switch back and forth, lay one, instrument, #down
and pick the other up.
If more power is needed It can also function as a pre-amp to run another power amp, and whatever speaker will handle it..
I'm combining it with a KCW-1 powered Sub fills in the bottom well.
[When I run 2 #guitar synth modules one is often a bass, the other steel drum, or other 'instruments' #at the same time.]
some acoustic amps are made for a singing guitarist, so mic channel is for dynamic mics, no phantom power , or token, not adaquate powersupply. 48v is needed to run many condenser microphones well.
Old Tube amps are occasionally including old tube sockets too, travel #to jams with them and I couldnt rely on it working, new tubes or not.
rewiring all the tube sockets to fit new ones can be done,
just don't ask how much..standing ..
writing about music
is like dancing,