Cadorman
Ambassador of the Catocaster
Well, I found myself bored this afternoon, so I decided to equalize 5 pots I just got. These are standard CTS 500k standard shaft audio taper pots for use in an SG, Flying V or something similar. If you are not using CTS pots some or none of this may apply.
Here I have measured each pot and numbered them from highest to lowest resistance.
Here you can see what I am starting with for values and that I have started to pry up the four tabs holding the pot together. I use a standard X-Acto knife. It's either a #1 or #2. The blade is small and thin enough to easily get under the tabs. I finish bringing them up straight to vertical with a small pliers.
Looks like this.
Here's what you want to end up with. The mounting shaft easily comes off, then remove and turn over the carbon track. This is what we will be working on. The actual rotating shaft and wiper can just stay sitting in the base cup. There is some grease underneath of this and that is it for parts. If you lift the shaft and wiper up you can see why you don't want to apply too much heat to the back of the pot. It will cook out all of the grease.
Now I measure the resistance of the carbon track using the two outside lugs. #1 pot has the highest resistance, so that is what I am shooting for. With the lugs facing you use the X-Acto knife to scrape a tiny bit of the carbon off of the very outside edge starting by the left wiper. Test the resistance again and keep doing this working clockwise around the carbon until you get to the desired resistance. Check where the brass wiper rides on the carbon. You want to keep to the outside of this.
It should end up looking like this or better. My eyes aren't that great.
Now, reassemble the same way it was taken apart. Use the small pliers to bend the tabs back over and make sure they are tight. Recheck the resistance from the left lug to center lug both off and fully on. You should have 0.0 ohms off and whatever your final reading was. It might be 1 or 2 ohms higher since you are measuring through the wiper assembly. As a final check, with your ohmmeter attached, do a complete swipe slowly from off to fully open watching the meter to make sure it has a steady increase with no severe jumps or drop outs. You are done.
Starting figures are on the left. Final scraped numbers in the center and final reassembled values are on the right.
I saved over $20 by doing this myself in 15 minutes versus buying the 550k pots from WD Music. I got these from Amplified parts for $4.50 each.
Here I have measured each pot and numbered them from highest to lowest resistance.
Here you can see what I am starting with for values and that I have started to pry up the four tabs holding the pot together. I use a standard X-Acto knife. It's either a #1 or #2. The blade is small and thin enough to easily get under the tabs. I finish bringing them up straight to vertical with a small pliers.
Looks like this.
Here's what you want to end up with. The mounting shaft easily comes off, then remove and turn over the carbon track. This is what we will be working on. The actual rotating shaft and wiper can just stay sitting in the base cup. There is some grease underneath of this and that is it for parts. If you lift the shaft and wiper up you can see why you don't want to apply too much heat to the back of the pot. It will cook out all of the grease.
Now I measure the resistance of the carbon track using the two outside lugs. #1 pot has the highest resistance, so that is what I am shooting for. With the lugs facing you use the X-Acto knife to scrape a tiny bit of the carbon off of the very outside edge starting by the left wiper. Test the resistance again and keep doing this working clockwise around the carbon until you get to the desired resistance. Check where the brass wiper rides on the carbon. You want to keep to the outside of this.
It should end up looking like this or better. My eyes aren't that great.
Now, reassemble the same way it was taken apart. Use the small pliers to bend the tabs back over and make sure they are tight. Recheck the resistance from the left lug to center lug both off and fully on. You should have 0.0 ohms off and whatever your final reading was. It might be 1 or 2 ohms higher since you are measuring through the wiper assembly. As a final check, with your ohmmeter attached, do a complete swipe slowly from off to fully open watching the meter to make sure it has a steady increase with no severe jumps or drop outs. You are done.
Starting figures are on the left. Final scraped numbers in the center and final reassembled values are on the right.
I saved over $20 by doing this myself in 15 minutes versus buying the 550k pots from WD Music. I got these from Amplified parts for $4.50 each.
