Humm after bypassing "boost" circuit in jaguar

[chadface]

Hi all,

I recently acquired a squier vm jag that had electronics issues. It was distorting really bad. I narrowed it down to the boost circuit and decided to bypass it. The boost is last in the chain, after the tone pot. I simply clipped and spliced the wires from the tone pot to the boost, and the one from the boost to the output. It works(no more distorting) but there is a loud hum when I touch any metal on it (strings, control plate, etc.). The hum goes away when I turn the tone pot down.

I checked all grounds and they look good. I'm not sure where to go from here. Any ideas?

 

[chadface]

Update for any future folks who have this issue. The polarity on the jack was reversed. It has 2 black wires (one that goes to the battery) and one yellow. I assumed the yellow was hot but that was incorrect. I don't know if it came from the factory like this or if a previous owner incorrectly replaced the jack. I swapped them and it is working great!

 

[Ronzo]

I had a similar problem. Bypassed the active bass boost, and the pickups sounded lifeless. Dropped in an Audere 4-band Jazz plate preamp, and the original P/J pickups sound a lot better, even with the EQ set flat. Very happy with this setup now!