Hi all, I just want to share this:

Kfir mentioned in another thread that he had good results running his fast drum-motor on a lower speed - the post is here: HUKY 500 Q and A (There is a link to the controller 3 posts below).

My setup: Perforated drum/fast motor. Kfir uses a variable controller - I bought a new power supply for a new one-speed-solution.
My original power-supply for my fast motor was DC 24v/2A, my new is DC 12v/2A. Half voltage gives me half motor speed (36rpm instead of 72rpm).
Using the same principle, a DC 18v/2A power supply would give me a speed of 54rpm.

The results is fine with my perforated drum (only 4 roast done, so I cant really comment on the taste yet), but there is one big improvement: Much less audible noise from the motor.
No electrical noise in my probes with this 12v power-supply (don't know about the variable one Kfir uses).

The plug is 5,5/2,5mm, center positive.