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.
I’ve got a 2×12 g100 II combo, it is Bad Ass!
Loud with unlimited clean headroom. I put a pair of WGS G10C’s in mine [with adapter rings] and it really is a huge improvement over the stock speakers.The boost channel is great if you keep the gain at moderate levels and the spring reverb really brings the surf. I’ll probably never sell this amp!
p.s – I’d love to replace the 2 ”red bull” caps :-DD, but its pretty impossible to find this value [2200uf/160v] of screw terminal caps in a 35mm width. I’ll probably use ‘snap-in’ caps and just solder the wires to the terminals.
I have one of these. It has a maching 4×12 cabinet. Sounds amazing. I’ve been scouring the internet for more information on it. I know it’s early 80’s and was designed to kind of replicate a fender twin. My amp is so solid, I’d take it over my buddy’s twin any day.
Do you know anything else about them?
Glad you are enjoying it. I really rate Yamaha gear and this one is no exception. Really well made and actually very good value over here in the UK I have heard them going for £30 second hand. Very under rated piece of gear.
Best wishes, Mikey