sovtek

Does anyone know what the two 2-digit numbers at the bottom of the text on a Sovtek 5AR4 mean? I ordered a replacement 5AR4. I know I should have ordered NOS, but I was in a bind and didnt have the money for NOS. The old tube had 21 09 and the new tube has 21 12 (Ha!). When the new tube warmed...

I recently got a Mig-50H in a trade. Previous owner knew very little about it, had it as a project he never finished. When I popped it open, I noticed a few things. 1) Someone replaced the heater wiring, including disconnecting the elevated heater voltage winding for V1 and replaced with...

I just replaced my tubes in my Hot Rod Deluxe with Sovtek 6l6wgc tubes and biased them at 60. The amp is way quieter now, but essentially easier to control. I've read these tubes are rated at lower watts. I like the sound, but worry it may screw something up in the long run. Is there anything I...

After a tube swap, I have something weird going on. *Before the tube swap, everything was normal- they were just old stock tubes.* At "1" (all the way down) I can just barely hear really gainy guitar (bad gainy) sound coming through. As I turn up slowly, the volume with the gainy sound increases...

So, the Pro Junior I recently acquired secondhand, has (new production) tubes that haven't been replaced in over at least 3 years O_O. Of course, I'm curious to see what sticking new tubes in it will do :p I'll be pleasantly surprised if it "wakes up" the amp even more than it already is! It...