GK 1001 rb speaker overload, is my guess

Hey, I have had my GK for only a few years. I bought it used, it sounded great a that point. guy how sold it to me claimed that this unit was send to GK and has the upgrado of the 1001 RBII circuitry... I am runing a cort 5 string soap bar bartolini active pick-up thru a boss DS2>line 6 bass floor POD. on a 1X15 (ashdown) speaker cab. it sounded prety good to me. the lows were realy low and clear on the extra low button... one day the thing made my speaker go crazy with distortion, so I took out the distortion pedal from my signal and still had the distortion. replace the battery on my bass and still with the distortion. at the end of the day I was resignated to have a burn out speaker.. a few days later I hoked it up again and sounded normal. turn on my distortion and still good. a few minutes later, no distortion been played, and boom speakr is full of distortion again. cheked the speaker impedance and was good at 6.9 ohms. So i tried it whith a Hartke 4x10 cab and it did the same thing. started out good then went crazy with distorted signal to the speakers.

I ask around with some guys who install car stereos and they told me it's probably a faluty volume knob. But I don't know exactly how to change this. and try again. is normal weld good enough? Do I need a certain temp on the welder to do this? has anyone heard anything similar, before I start messing up my amp?

Please help. I HAVE NO MORE MONEY FOR A NEW AMP!!!

cheers to all