I’m not familiar with those amps but I do know a little bit of history about them. Those amps were made by JMF Electronics, a company founded by Jon Flickinger in 1976. The Spectra-series is from the early eighties. The company was sold to Dean Markley who also introduced Spectra–series of amplifiers. …Solid-state ones - except for the Spectra 60T and 120T models, which were tube amps. I believe there also were “transition” JMF amplifiers that just had Dean Markley badges attached to them.
Dean Markley’s site has some schematics of DM products and with Google you should also be able to find complete (but non-factory) schematics to Spectra 60T from JMF. If you’re into that sort of technical stuff, of course.
Here’s a link to a youtube clip of a JMF Spectra 120T:
It’s either the camera, the guy behind the dials or the amp but it – IMO - doesn’t sound too good. In fact, that's one of the worst “tube” tones I’ve heard.