Problem with GK 400RB-III

[jameshdurham]

Hello everyone. I'm having an issue with my Gallien-Krueger 400RB-III head.

When I first power the amp on, or when it has been sitting idle for a few minutes, there is a loud popping noise similar to a speaker rattling if the volume knob is at half and the master knob is above 12 o'clock.

It is most audible on the B on my low E string. After I play for about 10 to 15 seconds, it goes away until the amp sits idle for a bit longer.

The noise sounds electrical and not as though something in the cabinet is rattling.

Someone told me that this is because the preamp is going out.

You gurus here are always so helpful. Any information you can give me would be appreciated.

Thanks

jd

[jameshdurham]

Just a little addendum in case someone sees this post in the future. I think maybe I was just expecting more out of my little amp than it's capable of handling. So long as I keep the volume around 11 and use the master responsibly everything works just fine. I guess I just need to upgrade for those times when I'm competing with loud band-mates. I love the tone I get from this little amp. I think I'm going to look at something else GK with more wattage.