There are a small handful of old tubes that need an impressively low voltage to work, though, and [J.G.] has put a few of them to work in this battery-powered audio tube amplifier. The key to the ...

The latest Katana amp puts the features of its big brothers into a compact, battery-powered combo that goes where you go ...

Battery-powered pocket amplifiers exist and street performers have pretty solid busking setups, but a truly worthy and ready traveling amp was still something that eluded much of the guitar world.