Grateful Dead Music Forum

A place to talk about the music of the Grateful Dead 

 #123319  by jmfranc
 Wed Jan 16, 2013 10:40 am
I have a 77 MXR Phase 90 that I amputating into a new case so I don't damage the original. Like the vintage Distortion + I modded with Waldo's generous help - I want to add true bypass, an led, and 9 volt plug for my board power.

I would do it exactly like the Dist + but there's one extra wire coming from the board - a grey one.


Dist + has: orange, yellow, black, red, and purple

Phase 90 has all the same but also has a grey wire that was wired to the center lug on the pot

And the Phase 90 has one pot and an extra grey wire. What do I do?

Bonus question: I read the Phase 90 used a reverse 500k pot. Can I use a standard pot and not effect the sound in some way?