Havent used this amp for anything but practice at low volume for a few years and its been good for that. I tried playing louder and it started make very unpleasant crackling, rattling sounds, this is with the volume and scoop (which is like gain) both up around 5 or more. Its a bassmaster xm200 which I got used about 10 years ago. Dont think its my bass or the patch cords because I use both with other amps and dont have this problem. From the reading Ive done it sounds like it might be the jacks in the amp and a possible solution might be to open it up and inspect the jacks, either re-solder or replace them. Anyone have any comments or other possible tests, solutions? Thanks.