The manual says you can adjust the feedback from 0 to 10.
Yeah, I can see that just by looking at the damn knob.
When I used to do them on my 805 SE’s monoblocks
0 was the min feedback and 10 was the max feedback (maybe Cary did the same)
When you a/b different settings you have to re-adjust the volume as it will be different.
As more feedback (10) gives you
1 Less gain (lower level)
2: Better distortion figures
3: Better damping factor (tighter bass makes up for average output transformers)
4: Not as stable into difficult loads (could ring or worse oscillate)
Less feedback (0) gives you:
1: More gain (higher level)
2: Worse distortion figures (usually second harmonic the "nicer sounding" one)
3: Less damping factor (fatter/thicker/heavier bass)
4: More stable.
This was the circuit diagram of my 805 mono’s I used to build around 40kg each, no feedback at all on this one, my output transformers were good enough in the bass to use without it, and a bit more complex than the Cary. https://ibb.co/PjLktwr