Pots, Wafers, Wipers, Shafts, Dimples
How do potentiometers actually work, and how are they built? In preparation for my tutorial on how to make a no-load tone pot, I dissected a couple pots (the same Bourns and CTS pots I’ve been looking at in my other videos). In this video, I explore the details of pot construction and how they actually work.
Correction: in the video at 6:25, I said that the narrow part of the wafer had less resistance than the wider part. That’s backwards! For the same length, a thinner wire has more resistance than a thicker wire. Similarly, at 4:37, when I said “more stuff to go through, more resistance”, it would have been clearer to say “longer length, more resistance”.
This is not a drill!
Next up in the series on guitar pots, I demonstrate how to enlarge the holes in your semi-hollow body top, to accommodate the larger diameter 3/8” pot shafts. Import guitars appear to use slightly smaller 8mm or 5/16” shaft pots.
In the video, I demonstrate using a Unibit stepped drill bit to cut very clean holes. Note you can also place some painters tape over the surface before drilling, to help produce clean edges.
The step bit helps enlarge a hole, step by step, but it’s also useful to have some fractional calipers on hand to confirm the hole size.
More on selecting pots, and evaluating tapers
Here’s part 2 of my potentiometer project. In this one, I compare linear and audio tapers, and compare the different audio tapers of Alpha, JS, Bourns and CTS pots. Then I go over a bunch of other factors to consider when buying new pots- tolerances, dimensions, shaft types, etc. More
When a pot is really just a pot
I’ve read stories of people saying how their guitar sound miraculously better after just changing to a different brand of pots. Are they just imagining it? Let’s investigate.
In my earlier post Pickup experiment – bypassing electronics, I determined that entirely bypassing the electronics on my Epiphone Riviera P93 did marginally brighten up the sound. However, we need some volume knobs and a tone control – we can’t just remove them all!More
Installing the Treble Bleed Cap
This is the followup to my previous video on how to select a treble bleed cap. Here in part 2, I explain some basic soldering skills, and then show how to actually solder the treble bleed cap in place.