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Rubber O-Rings under pedal knobs


Last year, I bought a MXR Clone Looper and put a D'Addario LokNob on it. The CL clears out any recorded loops by pressing down and holding the level knob. The LokNob is great because it lets me press and hold the knob with my foot without the setting change. It's also nice because it's made of metal, so it's more durable to step on than the plastic stock knob.

As great as the idea of the LokNob is, they're expensive ($11 each for plastic ones, $16 for metal). It's perfect for my Clone Looper, but I'd never buy an entire set for all of my pedals. I started doing some digging online to see if I could find a much cheaper alternative. I found this in another thread:

There are a few threads on this subject here, but I couldn't find much on what sizes to use, so I bought a 200-Piece O-ring kit from Home Depot for $12 to try it out. I took the knobs off of 5 pedals and put the O-rings underneath them. Since there isn't much info out there about what sizes to use, I thought I'd share my results:

  • #5 O-Rings (3/8 in. OD x 1/4 in. x ID x 1/16 in. wall thickness) are the best fit for most pots. I put two #5 rings on the shaft of each pot
  • The one exception I found was Boss pedals with 4 plastic knobs (DD-3, CS-3, CH-1, etc.). Those knobs were too small to fit two #5 rings underneath it, so I used one #5 and one #36 (the #36s didn't come in the kit, so I had to buy a separate pack of those. A 10-pack is $3 at Home Depot)
  • For pedals with larger knobs, I'd find what size from the kit fits inside the bottom of the knob and put a third O-ring in there (it varies by knob style, but as an example, a standard MXR-style knob fits a #10)
  • I don't recommend trying this on pedals with mini knobs. I ruined two of the pots on a TC Electronic Sub n' Up Mini when trying to take the knobs off. The knobs on MXR mini pedals are stiff enough that I didn't feel the need to try it on them

Overall, I'm really happy with the end result. It only cost me $15 and about an hour of my time, and now my pedals' knobs don't move around when I pull my board in and out of its case. It's cheap and easy enough that I'd recommend giving it a try.


I have done this on quite a few pedals over the years. I actually took my pedals to the local, home-owned hardware store and they helped me pick the right sizes. Even loaned me a screwdriver to make remove/replace the knobs. This is a great solution to a real world problem.


Silver Supporting Member
I use #31 O-Rings. They work really well with most pedals; you can get the knobs snug enough to not spin easily, but still able to adjust when needed. You can get them at Ace Hardware or order them online.

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