I've been toying with circuit simulation using LTSpice, and I simulated a guitar circuit to compare different treble bleed circuits. This simulation includes the pickup (this case, a Telecaster bridge pickup), two 500K pots (volume and tone), the treble bleed circuit, the guitar cable, and the impedance of the amplifier. The attached figure compares the frequency response of the following treble bleed circuits with the guitar at "half volume", which in this case would be at 5 on a linear volume pot, or about 8 on a log pot. 1) No treble bleed 2) 0.001 uF capacitor 3) 0.001 uF capacitor in parallel with a 220K resistor 4) 0.001 uF capacitor in series with a 130K resistor (the "Kinman Mod") 5) Input to the tone circuit is taken off the wiper of the volume pot rather than the input lug (the "Fezz Parka" or "50s wiring" mod) As you can see, all are effective in boosting treble frequencies. This figure supports what people say about the Fezz Parka mod, which is that it is the least "coloring" of the treble bleed options. There is a decrease in bass frequencies, but a clear boost in treble. A simple and effective treble bleed. The standard 0.001 uF treble bleed greatly boosts treble frequencies. This supports the conclusion that this treble bleed is very bright. However, I've also heard people say that it decreases bass, but that is not shown here. It might be perceived as less bassy since there is so much more treble. The 0.001 uF in often placed in parallel with a 220K resistor to also boost bass frequencies. This is clearly the case, but you can see that it really "colors" the unmodified frequency response. The "Kinman Mod" is something between the two extremes. It is a more tame version of a lone 0.001 uF cap. I personally like this treble bleed mod because I feel like it gives a brighter tone without sounding unnatural. Anyways, I thought this might be of interest to some of you techies. Keep in mind that frequency response is a "steady state" measurement, meaning the transient or dynamic response isn't captured. This is harder to measure and compare but equally as important, as it defines the character of sound.