Many folks who buy our tubes know that we use a special process to categorically rate our tubes so that players can select the tubes that best fit their preferred tones and styles. However, we get a lot of questions about our rating system, and what the numbers actually mean.

IMPORTANT BIAS NOTE: If you're replacing a tube with the SAME TYPE of Groove Tube (tube model and rating), you do not have to rebias your amp. In any other case, you should always have a qualified amp tech reset your amp’s bias whenever changing your tube type or rating number.



Early distortion, wide range, softer attack good for Rock and Blues solos.



Normal performance, great dynamic range/attack and best all around rating type for all styles of playing



Most dynamic range, most clean power/less break-up for power players, Jazz and bass amps.

Scott Ian / Anthrax

Scott is the co-founder and rhythm guitar player of Anthrax. Scott, with Anthrax helped create thrash metal in the early 80's. Scott and Anthrax have sold over ten million records worldwide, have multiple Gold and Platinum record awards, have been nominated for a Grammy three times, and have toured the world since 1984 on over seventy something tours. Scott had the idea to cover Public Enemy's Bring The Noise back in 1990. Chuck D and Flav rapped on it and the two bands toured the world together kicking the asses of expectations and stereotypes. Scott takes no credit good or bad for any musical genre that came after. Scott was very excited about the 25th anniversary of Anthrax's debut album Fistful Of Metal in 2009. Scott was also very excited about the March 2012 25th anniversary of Anthrax's classic album Among The Living. And while we're on anniversaries, Anthrax celebrated their 30th on July 18, 2011. Scott wrote Lobo: Highway To Hell for DC Comics in 2009. Scott is currently writi...

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