Power supply issue maybe ? I assume you're using the included power supply if there is one ?
have you tried different outlet / room ? Just to eliminate electrical issues ?
otherwise I'd contact their support I found them very responsive when I needed help with an Amplifire 6 a while back.
Got a different bass to compare? Nothing like this happening with mine that is out of the ordinary....my low-end basses with dubious wiring hum as always, and the better quality basses are quieter or dead quiet with normal settings.
Update: Turns out it was the power supply. Time to get a new One Spot. My bass does need to be properly grounded, but since I have been using wireless these last four years, I only found out when I finally decided to skip my board and plug in the old fashioned way.
I am digging this box, but it I am going to have to work harder than I expected to dial in what I want. I'm no tone junkie, but I don't think this thing sounds amazing out of the box. Hard work, waaaaaa.
And while I'm at it, I was looking for an answer to a question that was posed a while back. Were the Solid State and Tube amp sims based on any particular amps? I would love to have an Ampeg, a Fender, and an Aggy amp/cab trio as my three presets. I think. For now. Probably.