October 2009

October 21, 2009

Relax, Take a Load Off

Guitar Potentiometers Electronics, Epiphone Riviera P93, Video 91

In this video I demonstrate how to modify a tone pot to be no load, for true bypass. The change in brightness is subtle, but worthwhile. Don’t be afraid to open up your pots and have a look – it’s pretty easy to do. But be forewarned, some pots are easier than others to put back together! These Bourns pots are a bit dodgy, as you can see in the videos. In contrast, the CTS EP086 is very nicely constructed and easy to reassemble (as I showed in How Pots Work: Disassembly and Exploration).

October 21, 2009

Pots, Wafers, Wipers, Shafts, Dimples

Guitar Potentiometers Electronics, Video 191

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”.

October 19, 2009

This is not a drill!

Guitar Potentiometers, Semi-Hollowbody Electronics Electronics, Epiphone Riviera P93, Video 28

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.

October 16, 2009

More on selecting pots, and evaluating tapers

Guitar Potentiometers Electronics, Epiphone Riviera P93, Video 126

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

October 4, 2009

When a pot is really just a pot

Guitar Potentiometers Electronics, Epiphone Riviera P93, Video 173

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