when i have my guitar jacked in
my microcube makes a staticy noise or feedback when im not playing

whatsup with it?
It happens to me as well, but when the amp is near a laptop, monitor, etc.
Besides being a guitar player, I'm a big fan of the guitar. I love that damn instrument. Steve Vai

Kramer Striker FR422SM
Roland Microcube
Digitech Bad Monkey
Dunlop Tortex 1.14mm picks

bad connections maybe? poor cables, too much power taken from the outlet it is plugged into or maybe your pickups are making the noise. i experience zero noise even at full volume but i use an EQ pedal with mine so i get some noise and it isnt drastic either. i still use a noise gate but it isnt as bad as your saying. ive never gotten feedback (i wish -_-).
Schecter C-1 classic
Takamine GS330S
Roland microcube FTW!