Little bit of backstory here before I pose some questions: I've gigged with this Bassman 500 for 4 years, countless gigs ranging from main stages at outdoor festivals to small bars and coffee shops. I've never had a problem with it. It's always produced and always performed as necessary (running with typically 1 or 2 Rumble 15" cabs), until I recently did a live broadcast session and started to run into some issues. What I'm finding is that the gain in the overdrive channel (which I've used exclusively) all of a sudden has begun sounding farty and frankly like the amp is dying. I've used the overdrive channel with the blend 100% on and the drive to taste, which allows me with my precision bass to go from gritty to warm and fat with the turn of the tone knob and utilizing both preamp tubes as adequately as I could imagine.
Once I started noticing these issues I immediately assumed that the issue must be the tubes themselves, these came stock with Groovetubes that to my ear sound great. These lived in this amp and have worked great for all of this time. I replaced them with JJ/Tesla 12ax7's in hopes that the issue would subside. Unfortunately I've found no luck. I noticed this issue happens too, when using the preamp out as a DI, at times it sounds fantastic and then it sounds like it's dying again.
I'm posting to see if anyone has some insight as to what could be happening? If it's not the tubes in the preamp is there anything else I could check or should work with to try and fix the problem. I love this amp. It's light, and have always received compliments on my tone. And seeing as Fender has, from the looks of it, discontinued this amp; what should I consider going forward?
Once I started noticing these issues I immediately assumed that the issue must be the tubes themselves, these came stock with Groovetubes that to my ear sound great. These lived in this amp and have worked great for all of this time. I replaced them with JJ/Tesla 12ax7's in hopes that the issue would subside. Unfortunately I've found no luck. I noticed this issue happens too, when using the preamp out as a DI, at times it sounds fantastic and then it sounds like it's dying again.
I'm posting to see if anyone has some insight as to what could be happening? If it's not the tubes in the preamp is there anything else I could check or should work with to try and fix the problem. I love this amp. It's light, and have always received compliments on my tone. And seeing as Fender has, from the looks of it, discontinued this amp; what should I consider going forward?
