So I've been able to recently acquire a used KGSS. Using it with my 404LE, but I got it in anticipation of trying a 4070 and/or O2 at some point. It supposedly has a stepped DACT attenuator added (as original attenuator failed). It has some very noticeable static when I turn the volume knob, especially between each notch, but goes away completely when I set it at any specific volume level. The seller specifically disclosed this before the purchase, so all is good. I can live with it, as it sounds so good with the 404LE.

My question is - in the future, if I wanted to eliminate this minor flaw, is it as simple as replacing with a new quality attenuator? (I'd have to find someone locally qualified to do it). Mind you, this is not annoying enough that I need to address immediately, but assuming this KGSS works out with a 4070 and/or O2 in the future, maybe I endeavor to fix this last bit.

Just curious.

it's probably just a matter of turning it several times to clean the contacts, or spraying contact cleaner on it (on the stepper)

Ditto what Dan said, spray the contacts (which are inside the clear plastic housings, you need to clean all four sets) with a good contact cleaner like Caig DeOxit and then cycle through all the positions a dozen or so times. If that doesn't work then you might have a cold joint somewhere, probably at the input where the attenuator we replaced.

The KGSS works well with the 4070/SR-007 so it is well worth it to have it running at 100%.