A while back, I described some problems with trying to use treble bleed on this guitar with three volume pots and a 3-way switch. When turning down one volume pot, that pickup retains brightness, but the other pickups get duller. In this diagram, with middle and neck pickups in a blended switch position, the middle volume is up full and the neck volume is turned down. The middle pickup high frequencies have a path to ground through the neck treble bleed cap. More
Guitar Treble Bleed
- Gear Diary
- Guitar Circuit Wiring
- Guitar Potentiometers
- Guitar Preamp Cable
- Guitar Tone Capacitors
- Guitar Treble Bleed
- Pedal Building
- Photo and Video
- Semi-Hollowbody Electronics
- VOX AC15
Update Feb 4, 2011: I wrote up a number of ideas for solutions in this blog post.
Before plunging into the details, here’s the abbreviated version: the Epiphone Riviera P93 guitar has 3 pickups and 3-way selector switch. There’s no way to turn off the middle pot other than turning it all the way down. Because of this, the volume pots must be wired with independent (aka decoupled) wiring, which results in bad treble loss when turning down. And because of this wiring, there’s no way to use a treble bleed cap since turning down one will result in loss of high frequencies in the other. This problem can be avoided on a typical two pickup 3-way switch (traditional Les Paul style) guitar since it can use non-indendent (coupled) volume wiring. Read on for details… More
In part one of this, video I explain what treble bleed is, and how to evaluate and select the right cap. I demonstrate my G&L ASAT III which has a treble bleed cap on the master volume, and I compare that with my Epiphone Riviera P93 which has no treble bleed caps (yet).
The caps I tried are (as shown left to right): Silver Mica 100pf, 390pf and 1000pf, a tiny 1000pf ceramic cap, and Sprague Orange Drop (polypropylene) 1000pf, 3300pf, and 6800pf.
The tolerances on the caps are a bit all over the place. I measured the 1000pf caps on my DMM and all were closer to 1250. The 100pf silver mica was over 250! This is assuming I can trust my Mastech DMM.