Putting a High Bypass on Volume Control

stock pickguard
This modification does not alter the appearance of your guitar.

The (sometimes) Problem:
Sometimes the volume control on your guitar will almost seem to function as a tone control -- as you turn the volume down you lose some of the high frequencies. This is a function of the pickups, tone and volume controls, and the first gain stage reacting with each other to make up the complete circuit. The theory of why it happens is far beyond the simple discussions on these pages -- let's just say it sometimes happens, and that a guitar which is really plagued by this when plugged into one amp may suffer little when plugged into another amp or a stomp box.

This is one of those modificatons that I can not recommend either for or against. Sometimes it seems needed, other times it is a waste. Which it will be for you depends strictly on your ears and on the particular guitar/amp combo you're dealing with. I've done it on one guitar (a cheap Korean Squier) and noticed a significant improvement through one amp while it made little difference with another (the second didn't have the problem as much to begin with).

It is interesting to note that some guitars are manufactured with a bypass capacitor on the volume pot -- and some people take them off. Other guitars are manufactured without a bypass capacitor -- and some people put one on. It's purely a matter of personal preference, as you can see.

The Solution:
If you decide you need to do this, simply place a very small capacitor (0.001uf or thereabouts) across the "high" end of the volume pot and the pot wiper. I've also heard of people additionally placing a 150k fixed resistor in parallel with the capacitor -- I never used the resistor so I can't speak for how effective that is.

High-bypass Capacitor on Volume Control

You can also replace the volume control with one having a push/pull switch, so that you can switch the bypass capacitor out of the circuit when it is not needed -- thus having the best of both worlds.  If you use the switch I would recommend the resistor – it should prevent the capacitor from building up a charge and causing a "pop" when the switch is opened or closed.

High-bypass Capacitor on Volume Control with Switch