Ryan Canestro linked me to these cool videos from Planetz.com where John Cooper wires up and compares a variety of capacitors in his electric guitar. The capacitor value and material can make a big difference in the sound and it’s one of those mods that only costs a few dollars. Definitely worth trying! I know I will.
Here’s the link to the blogpost: Crazy Tone Thing
It is a fascinating attempt but ultimately flawed because he doesn’t measure the actual capacitance values. In a passive guitar circuit, for a given capacitance value, there is no discernible difference between types of capacitor. Much more worthwhile to spend your time experimenting with different values and different pot tapers.
There’s a good article with data to back it up at http://www.aqdi.com/tonecap.htm
BTW: His piece on volume pot tapers is much more informative