This is a 100 watt Yamaha guitar head, designed by Paul Rivera, made in Japan, and still used by Mike Stern. This is one of the best solid state amps ever made for a loud, clean sound. There is a tear in the grill, the plastic piece securing the light isn't there, and some of the knob covers fell off, but it works fine.
Yamaha G100 II Guitar Amp Head
I really like this amp – it’s big. Big knobs, big sound, big heavy wooden box and transformer, enormous capacitors like cans of red bull. From the outside it looks like it is stuffed full of vacuum tubes – so what’s not to like?
Inside it is really well put together neat wiring looms, circuit boards and plenty of cooling. I would definitely like one of these of my own but maybe a combo would be handier for me.
Play wise it has two channels a straight clean channel and a fuzzy pre-gain channel. For me there are way too many tone knobs to play with including a parametic EQ which I could mess about with forever and never learn any of my songs. Also this amp as a lovely reverb sound and I think these amps would be great in a rock n roll set up as they are surely loud enough for most gigs.
This one just had a little problem of a loose transformer. Strangely the transformer, which must weight several kilos, is held in by four skinny little screws. Quick fix for this sort of thing is just to tighten them up every twenty years. If you don’t then it could be kind of a mess. What I also add is a little threadlocker paint that keeps the nuts tight even in the event of a little vibration which is inevitable on a transformer.
Also the little neon lamp had a broken lens. Easy enough to replace although it turns out hard to find a one big enough so I had to improvise a reducing bezel with a washer. Not brilliant but enough to keep this amp going.