Weird problem with my amp...

[flareaga]

I use a Gallien-Krueger Backline 250 head (125W) and a GK Backline BLX115 (200W power rating) And during gig, (where the volume was maxed, but no "boost") I was playing on my Shecter C5, and it started getting real distorted when I kranked the bass up and volume down. Now, you know the kind of pickups those basses have...plus the bass wasn't setup very well at all, it's all still from the factory, so I thought it was that, because when I plugged the Thunderbird in, the amp sounded great. I noticed at tad quietr then usual, but it was no big deal. Then I brought it back to practice, the next day, at low volumes especially, you can almost hear a distortion coming out of it when you play. At high volumes it kinda goes away, and when the whole band plays, you don't hear it at all. But I also noticed it doesn't seem quite as loud as it used to- not much difference (it's still loud even to play over a drumkit with our loud ass drummer and beats a 60 Watt marshall) but I'm concerned. At low volumes it sounds like distortion is turned on...just all fuzzy sounding. And I REALLY notice when I use a footswitch or pedal.

Any advice?

 

[steve66]

Are you able to plug another bass in and check? My active bass gets distorted when the basses 9v battery is on its way out.

 

[flareaga]

Yeah, I used the Thunderbird (Epiphone -_-) at practice. I heard the distortion then.

 

[flareaga]

Really? No other thoughts?

 

[myhot4]

tried a different cable? tried another cab?

 

[JKT]

Hi. In your post you mentioned "bass up- volume down"

I'm a long time GK user. I don't have clear mental pic of what your gain structure is but- it's possible that if you're cranking a hot bass all the way up, your input gain(volume) is way up and you start bringing the master volume (woofer?) down too far below those relative input levels that you could be getting some beginnings of input distortion made worse by the amps inability to develop any headroom. If the T-bird sounded okay I would think the other bass is one of you troubles but not a defect, as this sounds to me like a level problem.

The boost feature used to be foot switchable years ago, but now with it being on all the time as part of the gain structure, it may be exacerbating your problem having it all the way off. Let us know what you come up with.

JKT

 

[flareaga]

Thanks, I'll look into it more today.
I think I kinda recall doing this way back too, I'm not sure.
If not, Looks like I'll be giving my local music store some more $$$$