Re: Battery Powered Amplifier
I've gotten a lot of use over the past decade from Fender Amp Cans. The Amp Can is my basic "playing at the nursing home" amp; I run a mic into each of the two channels –– cheap Samson low-impedance dynamic mics, with line transformers -- and use the "Mic" channel for vocals, the "Guitar" channel for instruments (usually acoustic guitar, banjo, and ukulele).
Since the mic signals are apparently a lot "hotter" than those from pickups, I rarely run the gain over 2 or 2.5. There's a fairly effective "tone knob" EQ control. The Amp Can has a rechargeable gel battery and will go perhaps 3-4 hours on a charge. I have two, which I alternate, and one's on the charger at all times.
There's a "Gain" button that overdrives the "Guitar" channel, if you want to play "grunge mandolin," but I never use it. Not as sophisticated in terms of tone controls as some of the other amps mentioned above, but I've found mine to be real workhorses.
Gibsn: '54 F5 3pt F2 A-N Custm K1 m'cello
Natl Triolian Dobro mando
Victoria b-back Merrill alumnm b-back
Stradolin Vega banjolin
Sobell'dola Washburn b-back'dola
Eastmn: 615'dola 805 m'cello
Flatiron 3K OM