My DRRI just went quiet. It’s about 4 years old. I play it about 5-6 hours a week. Only maintenance I’ve done is replace v1 and v2 with EHX 12ax7s because the originals got noisy. Recently, it’s been noisy again with that radio static you get when a preamp tube gets noisy. I decided to live with it for time being. Today, I turned it on and got some fairly loud hum, then a crackle and dead silence. I checked the fuse, the connections, and all the inputs. Both the power tubes glow orange when turned on, but not so much for the preamp tubes. I pulled v1, nothing. Tried switching v1 and v2, nothing. In my experience, I’ve never messed around past v2. I’m not even sure if I can tell if a tube is blown when I see one. I guess after four years, maybe it is due for a trip to the amp guy, but I sure would like to avoid it if I can. Any ideas?