Phase Reversal Switch

john horton

Feb 4, 2010
I want to add a phase reversal switch to my 5120 to put two P90s out of phase with each other. I saw on this site a diagram for the switch, but I'm not sure where to solder the grounds and leads. What gets soldered to the + & - inputs and outputs of the switch and how does this all fit into the wiring harness. What arrangements must be made to make this work? The pickups have a single lead and a braided ground wire.


Senior Gretsch-Talker
Gold Supporting Member
Nov 13, 2009
Monkey Island
The input on the diagram(toprow of the poles) is where the signal (from your P90) comes in...
"+" Usually denotes the "hot" or signalwire, "-" is the ground.

The middle row of poles attach to where the pickup normally would go. One wire to the lug of the volumepot. One wire to the back of the pot.

Ignore the blue dotted lines. Those are the internal connections being made.

As long as you distinguish between the top and middle row it doesn't matter whether you mix up your plus and minuses...

Good luck!
Last edited:

mr coffee

Country Gent
Oct 7, 2009
Single core + braid is gonna be iffy on a phase switch. You turn that braid into your hot lead, that's begging for noise. I don't know about you, but I dislike re-wiring pickups unnecessarily; tends to be delicate business. If you're confident doing it or know somebody who is, it shouldn't be hard to rewire one of those P90s with two core. Phase switch needs to happen to one pickup before volume, tone or selector; the other remains wired as normal.

One of the best resources I've ever seen for this sort of stuff is Adrian Legg's Customizing Your Electric Guitar. Great book with lots of ideas, well written and easy to follow even with no electronics background.