So my 15" 100 Watt Bass amp is making a VERY loud hum, like hurt your ear drums loud, when the volume is turned just enough to actually hear my music. However, when it is just on, no problems. When there is just a cord plugged in, no problems. With a cord and a pedal, and even an input cord to the pedal plugged in, no problems. As soon as I plug in one of my basses though I get this feed back when I turn up the volume. I have one electric bass, active, and 1 acoustic electric bass.
The amp is the Acoustic B100
Any suggestions? I've already tried new cords.
Got to suspect the instruments - do they do this with other amps?