Mc5baby, if you still have trouble with the tight volume control, it may be that the steel knob is touching the sides of the wood enclosure. You can remove the knob and recenter with an allen key. If that is not the issue, and it seems that something internal is awry, one potential fix is to seat the preamp facing up (so the volume knob is facing toward the ceiling, remove the volume knob and place a drop or two of oil into the mechanism). Of course you should check with Mick first to confirm if that would be an appropriate course of action. I expereinced similar stiffness with my input switch over time on my Supratek. I resolved it another way (had to resolder a new input switch I got from Mick), but the Tech who worked on the preamp for me (Nick Gowan from Truesound) had some positive results by just applying a dab of oil to the switch mechanism. Anyway, just a thought - again, no substitute for confirming with Mick on best way forward, but thought I'd share my experience, which has similar symptoms to yours.
Cheers,
John.