How does a phase switch work on a guitar?
This phase switch reverses the neck pickup phase (ground becomes hot, and hot becomes ground), so frequencies in common with the bridge pickup tend to cancel. This tonal change requires no active electronics or battery, yet gives a distinctive, scooped sound that works well with both clean and distorted amp settings.
What is phase reversal guitar?
An easy modification to get more tones out of your pickups is to wire in a phase reversal switch. This basically swaps over the signals from your hot and ground wire. ... When you reverse this signal they start to work against each other “ out of phase” and produce a thinner more trebly tone.