Bass amp causes any amp to make funny crakling noises...why?

My bass which I have had for about 5 years, makes any amp I plug into make low thumping/crackling noises. Any ideas how to fix it? It is an SDGR bass by Ibanez, and I have pluged it into 3 different amps- no idea what kind though..
I have tried different cords, and other basses work fine in these same amps.