BTDR-1H Rev module factory implemented in combo amplifier. Modded...

[HF1600ie]

Hi there,
Thanks for the explanations. Sometimes it gets a bit confusing for an hobbist like me

The "mixer" trim pot sounds nice and I´m glad it is possible. I see it all the times in pedals. If I had the space I would even place it as a potentiometer in the amp. But, I don´t. So, I´ll think about what to do. Maybe... the most reasonable and easiest option would be to set both R22 and R23 to 33K. They would be balanced and it would be "set and forget".

About R21, I have tried a 47K reverb pot which seems to be "softer" on the global effect. But, in both cases, I had to set R21 either at 22k or 47k respectively to control the pre-delay "slap".
I am trying  to have a Reverb level pot that works from 0 to 100 with many shades of "useful" reverb in between.
As you said, I probably could have done that in R22 and place a jumper in R21.

I was thinking yesterday that maybe the 100nF feedback capacitor is preventing oscillation? I am convinced the feedback loop is wired properly in the right spots. I will re-re-re-check.
I had oscillation in previous attempts, but I was wiring the loop at different spots. In those previous attempts, I only used the 47K pot alone.
Right now, I have a fixed 10K resistor in series with a 100nF cap. Only.

I will see If I can make some clips for your to have a listen. A clip is worth a million words