Join Date: Nov 2011
Location: Vienna, Austria
Hum when connected to power supply?
I just installed a pair of EMG Pickups in one of my guitars. I'm playing through a M-Audio FastTrack, which is USB powered and connected to a MacBook Pro.
Here's my situation:
- When the MacBook power supply is plugged in, I get a really loud electrical kind of hum, which STOPS when I touch any metal parts in the control cavity (jack, switch, etc.)
- When the power supply is NOT plugged in, the electrical hum disappears, but theres a hissing sound (like hiss from a high-gain amp), which gets LOUDER when I touch some metal in the cavity
It doesn't matter if the volume pots are open or closed, behavior is always the same. I think it's some kind of grounding issue, but I don't know where I should start looking, as to my eyes the wiring seems perfectly fine. I have another guitar with factory installed EMGs, which doesn't show this behaviour. Also I have installed them myself in two other guitars and never experienced this problem.
Thank you for any help or ideas,
Last edited by AlexFinger919; 04-26-2013 at 03:57 AM.