Comments about Groove Tubes GT-12AX7C Pre-Amp Tube:
The best current production 12AX7 that I've tried. I use it in a Frenzel Champ Plus Blackface. Compares favorably to the best NOS tubes I've tried. It has a nice, deep round tone when played clean. With overdrive it has a smooth, even distortion. When cranked up it drives the power tubes very well. It also sounds great in my Blackstar DistX tube overdrive. Gain is actually about 110%. Slightly higher than other 12AX7's. But even though it is great for metal, it sounds excellent for any application.
