Maybe a weird question, but what should I do with a rattling power tube? I have an amp packed with 6 RFT EL34s, and one of these tubes always rattles when I'm playing through the amp (I mostly play bass). The rattling is not amplified so it's not microphonic I guess. When I play on one of my other amps, I sometimes also hear it rattle. For that reason I installed 6 spring retainers, but unfortunately the rattling is still there. Only thing left to do is throw it out?