Help with Phase 90

[JohnnyNeck]

Hi.

I've been annoyed by my Phase 90 volume boost for some time and thought it would be a good idea to try the R7 mod with a pot as explained here: http://www.erikhansen.net/?page_id=31

To replace the resistor with a pot should work as an adjustable output for the pedal.

The only problem is that there's no explanation on how to wire the components. My first attempt was to cut off the 150K resistor (R7) and solder to wires to the each of the R7 solder lug at the PCB. I solder the wire from the inner R7 solder lug to terminal 1 on the pot, the outer solder lug to terminal 2 and finally terminal 3 was connected to ground the same place as the battery snap. I'm pretty sure this wasn't right as the pedal didn't work at all.

I thought I was smart, but no. Can somebody please help me?

[Fender3D]

It would be advisable to check what's written on the net, looking at a proper schematic when modding circuits...  
the 150k resistor controls the PNP's feedback, it's connected between its collector and base.
Since it's a resistor you should connect your pot as a variable resistor thus you'll connect only 2 lugs.
No GND connection.

[JohnnyNeck]

Thanks for the help. When I couldn't find a good guide on how to do this I decided to wire it as a guitar volume pot. I'm not very good at the art of electronics. But I think it's a lot of fun.

No ground connection and variable resistor is understood.
Considering the pot lugs. Should I connect the wires to lug 1 and 2?

[Fender3D]

the transistor's gain will decrease when lowering the resistance, so 1 and 2 or CCW and taper, better a 50k pot and a 100k/120k resistor in series

[JohnnyNeck]

Thanks  I'll try that.