I'm afraid you simply can not get great distortion without some hot glass in the back of your amp.
I know, I know, you solid state guys are going to try and tell me I'm wrong, but I used to BE one of you solid state guys. I tried everything, and I was never happy with my distortion sound. It was, you know, OK, but never great. Then I got a tube amp. NOW I know. You just can't do it without hot glass.
That being said, for really CLEAN sounds, there are some amazing sounds in the land of the semiconductor. I won't bother to mention the JC-120, as it is pretty well covered in this thread, but the other paragon of transistor clean glory is the Polytone Mini-Brute. It sounds like dog shit when it distorts, but you will find very few clean amps that can compaire. I've got two of them in the shop, because it makes it easy to hear when a guitar is not quite right, and because they can handle bass guitars as well as they can electric guitars. A truly GREAT amp. If I were ever to do another Jazz gig (not gonna happen, but you know, IF), I would bring one of my Mini-Brutes.
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