Are you certain it’s the amp?
Just trying to rule out some easy first things to check, like trying a different instrument cable, check output jack on bass and also a new battery if bass is active.
Seems like 99% of issues I’ve had were cable related.
Wishing you luck and I hope you’re able to resolve the issue soon.
Good point, Daxxy. But, please allow me to correct a grievous oversight here. @B Dax, you are now member #1437 in the Fender Rumble Club. Congratulations and welcome. I know from your years of participation here that you already know about your Rumble Club Wiki page, the repository of all Rumbling wisdom and knowledge. And you've participated on the Rumble LT25, Studio 40 & Stage 800 club sub-thread.
My sincere apologies for this error now corrected here.
Rumble On!
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