Hartke Kickback 12 Buzzing

I've had my kickback 12 for about 3 years and just recently it started buzzing, which increases with volume and treble. The sound is like distortion on a bad guitar amp, or the fuzz in between radio stations. It does this completely unplugged from any of my gear, so it's for sure not my bass or my pedal. It even does this with headphones in. Question is, how do I fix it?

Also when I turn it on it makes a loud pop noise.
And.. when I increase the volume while it's plugged into my bass the amp makes a crackling noise. These things don't bother me, just putting more info out there.

The tone is fine, if you get what I mean. Bass, mids and other tones come through good, but there is that obnoxious staticky hum always in the background while I play. So it's kind of like nothing changed, but the buzzing was added with my tone.

 

I just tried that. I heard a little crackling when it was shifted back and forth

 

The volume knob does!

 

Thanks for your help man. I'm thinking of taking it up to where I bought it and asking them what they think.

 

I'm back. I've done some research, asked some guys at different stores, and even looked at other amps. Unfortunately, I've come to the conclusion that some amps just buzz.

Especially with an exciter and highs at 75%+. I've been using the noise gate on my Zoom B3 and it has helped a lot. There is basically no sound when my hands are off the bass. There still is some buzz behind my notes when I play, but I'm gonna see if a physical noise gate pedal would fix that.

My amp doesn't cut in and out when I rock it back and forth. I guess that was just a one time thing..? So that's a good thing.
It pops loud when I turn it on, but I can completely get rid of that by turning the volume all the way down before hitting the on switch. A lot of people have a popping noise in their amp. Apparently it's pretty common.

The only problem left is the volume pot crackles when I turn it with the bass plugged in. Most people say this is from a dirty volume pot. I just gotta figure out how to crack her open and spray some air in that bitch!