Slight humm on Fender Acoustisonic 90
 

Hi all,
I purchased an Acoustisonic 90 today...tried it out at a local music. I used their cable to connect the amp to my Taylor 414ce. The sound was great and it went home with me.

When I got home, fired up the amp, connected to my guitar and heard a slight hum. When I put my hand on the metal part of the cable, the hum disappeared. Grounding problem? If so, suggestions for a remedy?