It’s a Randall Diavlo RD40C, 40w all tube combo app with a serial FX loop. It has 4 preamp tubes of the type 12AX7 and lots of gain. I think it’s geared to modern high gain metal.

As I said, clipping/crackling appears at appr. 3 o’clock (up to the maximum) of gain and volume on the dirty channel. At lower volume/gain settings, it goes away but I’m afraid I’m not entirely satisfied with this.

BTW, I returned it to Thomann in Germany. They’ll send me a replacement in a few days so I can find out if it’s some kind of mismatch between my amp and the pedal.

I’ll post an update here.