Since no one has opined yet... Hum could be a power supply issue, or ground loop behavior in the connection to external equipment. Do you get it using just headphones attached to the instrument? The whine is curious, what front panel buttons effect it? If West Cooper shows up at the KIN Group, he has experience with rebuilding way old electronics and might take a stab at your way new one. Or I can poke at the thing sometime.

Hum was minimal, and with unbalanced cords out, so not worried there. But whine appeared in both headphones and effects output (not the dry outputs), and increased with every button pushed (which led to the hypothesis that it's power related, assuming a button increases power drain). Though no whine in dry outputs would indicate otherwise. All that being said, I sold the unit as-is, shipped it out Monday. Tnx anyway.