How are your 512c knobs?

[macr0w]

I have 2 that I bought at the same time a few years ago,

They both seem the same to me.

Maybe they changed a part between the 2 you bought.

[hazelmossobrien]

open it up and see if there is a thread you can loosen internally, that potentiometer needs to be able to be tightened and loosened one way or another.

[SRS]

I have 6 of them in a Lunch Box and they do vary some between them. One in particular is noticeably stiffer than the other 5. But it stays where I put it. It does not bother me though. There are 2 set screws in each knob. It is possible that the knob was pushed in all the way, then the set screws tightened, causing the knob itself to bind on the post or outer portion of it. Take an allen wrench and loosen the set screws and pull the knob out a bit and retighten it and see if that changes the resistance.

I would shy away from spraying any lube or cleaner into the pre though, unless you really know what you are doing and have the right spray (Caig Pro-Gold or Fader Lube, or Deoxit...)

[Akoppenheffer]

Originally Posted by SRS

I have 6 of them in a Lunch Box and they do vary some between them. One in particular is noticeably stiffer than the other 5. But it stays where I put it. It does not bother me though. There are 2 set screws in each knob. It is possible that the knob was pushed in all the way, then the set screws tightened, causing the knob itself to bind on the post or outer portion of it. Take an allen wrench and loosen the set screws and pull the knob out a bit and retighten it and see if that changes the resistance.

I would shy away from spraying any lube or cleaner into the pre though, unless you really know what you are doing and have the right spray (Caig Pro-Gold or Fader Lube, or Deoxit...)

That sounds about right... I'll have to check it out. And I won't be going in there with like a can of WD-40, haha. I know better than that. Thanks for the suggestions.