McSpunckle wrote: This thread is destined to be nothing but unavoidable innuendo.
I'm SHOCKED it doesn't happen more, the way we throw the muff around up in here...
Anyhoo, if you really like the tone of the muff and plan on keeping it, I would highly recommend unsoldering the plastic jacks from the pcb and wiring real metal jacks in their place. It is not very difficult to determine how to wire them if you conceptualize which traces connect to which part of the plugs, and then you can switch the position if you want them to match all your other pedals (in goes on the right, and out goes on the left, sneaky russians.) I would bet you can find a diagram of this on the interwebz somewhere.
It does require suspending the pcb differently (I'm assuming we're taking about a later black russian muff, not a green one) which is actually a good thing b/c it takes any of the stress of plugging/unplugging plugs off of the board, but needs some creative and careful consideration. I widened some of the unused holes where the jacks are mounted and used pcb posts.
You will NOT find new pots to match with the D-shaped shaft and to top it off they used different length shafts across time. Again, the ideal move is to widen the holes in the shell and just replace
all the pots (and your knobs) but again you're making it further and further from "all original." I found these two mods were entirely worth doing in a muff that I used regularly and needed to be reliable, but was okay with removing any resale value purists might be looking for in it.
I went so far as to rewire everything as well...be very careful when changing components, as the cheap wiring they use is very thin, gets dried out and very easily becomes disconnected from where it's supposed to be.
Easy for me to say, I'm comfortable with an iron and have used/fixed/modded/flipped more of these than I can count across the years. It's a great circuit to work on for peeps without a lot of experience b/c of the way everything is spread out and easy to get at. If you're not into any of these changes and are really interested in keeping it stock, PM me and I will delve into the parts bin and see if I have any spare original jacks and pots.
EDIT: I re-read your initial post. If the tone pot still works but spins, you've probably just got a loose pot/knob or both. If the pot itself is loose you're in danger of snapping wires off when it spins, but this is a way easier fix than replacing the pot, and it'll keep your muff more original.