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Showing results for tags '12ax7'.
Problem: While playing recently, my DT-25 suddenly dropped volume significantly and had a slight burning smell. I figured it was a tube(s) going out, so I bought some new ones and replaced them, but when I went to bias them, they were super low! Instead of the 25 (+/-3), they were around 7-8. I turned the bias, but then the weirdest thing happened - any turn up would start an unstoppable climb to 40-50, then it would suddenly kick down to 14 or less. It would stay that way until I turned the bias up again, and then the same thing every time. I checked the fuse, but it seems intact. Since power was going to the tubes, I figure it can't be that anyway. I may be wrong, but I suspected it may be kicking into Low-Volume mode as a safety feature. Any idea what's going on? How do I fix this?
DT50 212 --- amp went out on me after about 2 months, a quick gurgle as tubes burned out ... then nothing. Thusly, I looked at the tubes ... the EL's were glowing bright, 12AX7's were out. Went to Guitar Ctr and after being assured they'd work, I got the Groove Tube russian brand. I would avoid chinese brands also. Russian just seems better sounding to me. Easy to replace and took about 1 minute of careful pressure to install. Unplug too ... duh?! LOL. I immediately noticed that the factory 'hiss' was nearly gone (like 90%), and the sound was more colorful. I looked online and noticed the EH stock brand was much cheaper than the GT brand. As well, each topology was more defined. 3 and 4 are now my fav's. Wonder how the sound will be if I replace the EL's with a high quality brand? Bribrew