I think the germanium transistors increase the life of the battery, there is no ac adapter plug, but you really dont need it. If you have a tube amp, buy it. If you dont, get a zoom driver, or a sovtek mig 100 tube head. I would definately buy it again, I just wish I had an older one. Only 2 knobs, volume and attack.
Attack is mostly a tone control.
The tone is really trebley and harsh but gets smoother when you turn your tone control down. Also a neat trick. If you unplug the cable from the input jack the thing turns into an oscillator thing, sorta pseudo theremin but you gotta touch it. Turn the attack knob to vary the pitch manually. Sonic Youth fans take note.