As was stated earlier, these amps were pretty much the same head power-wise(60 watts with two KT88's OR 6550's--not exactly the same tube, but very very close--KT88's sound a bit better, but are more expensive). The exception being the earliest heads like the Sonic, with two EL34(40 watts), but those are very hard to find, so I won't even go there. The subtle difference with the aformentioned heads is in the pre-amp voicing and features(some of the amps you mentioned, like the Sorado, were bass amps!) The basic rundown: guitar amps built before '69 (approx.)featured volume, treble, contour(an early sort of midrange contol), and bass controls, no reverb or tremelo, and only two input jacks. The grille cloth featured a gray diagonal weave pattern. In '69, a midrange boost switch was added, as well as reverb & tremelo(with an added driver tube), plus four input jacks(two normal, two bright). The grille cloth was changed to a silver and gray rectangular "Fender" style pattern. By '71 a solid state rectifier replaced the tube one, adding a few more watts of power. The 60 watt bass amps pretty much stayed the same--two input jacks, volume, treble, bass, with treble and bass boost switches. The tone stacks were voiced a little differently(to cover the bass guitar frequency spectrum)but in my experience, to run a guitar through a Sorado or 200s(two identical amps)doesen't yield the same results like a black face Fender Bassman. Same change in the grille cloth and rectifier as the guitar amps. As silly as it seems, the amp model names were different depending on what kind of speaker cab it was paired with, even though, within each catagory, they were all the same amp. For example, the 200s 60-watt bass amp was packaged with a 2x15" horn port cab with JBL's; but for less money you could get the "Sorado" package: same amp head/different name paired with the same sized cab that only had two simple round tube ports(less labor intensive to build)and loaded with less expensive CTS speakers.