I had this Trace Elliott SuperTramp 80W solid state half-stack many years ago.

[Kaz Kylheku]

I wasn't into modding at the time; I only saw the schematics long after I sold the thing.

It was a very poor quality build. The day I sold it, I was embarrassed because the reverb stopped working. Also the connection between the pre-amp board and power amp was very flimsy, using extremely thin hook-up wires (like 28 AWG or something ridiculous). It developed a cracked solder joint: touching the wire caused a rumbling sound and intermittence. I can't remember whether I reflowed that or not. The 4x12 cab was loaded with some kind of 75W Celestions, but wasn't very well built. Particle board crap; not even plywood.

It didn't have enough gain for my tastes. Forget brutal palm-muted chugs. There are some trimmer pots on the preamp board that look like could help in that department, if I had known what to do with them at the time.

From the schems you can see that it uses MOSFETs in the power section. The voltage amplification stage is another diff amp. There is current feedback with a 0.3 ohm resistor, 1 uF cap and 1k Ω resistor. Voltage feedback is configured at 56 kΩ　over 560 Ω.

I don't remember that amp having a response that I would today associate with current feedback, at least in the bass range. Probably this is because of the rather low 1 uF value in the current feedback circuit. I haven't done exact calculations, but it looks like this creates a high pass filter that will basically nuke the current feedback signal across the bass, such that the reactive effects will be absent.

If I had the amp again today, after playing with the trimmer pots in the preamp, the next thing I would try would be a higher capacitor value there.