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.

Zach Myers / Shinedown

Multiplatinum-selling rock quartet Shinedown formed in Jacksonville, Fla., in 2001. Guitarist Zach Myers joined as a touring rhthym guitarist in 2005 did a brief stint as bass guitarist on the 2007 departure of Brad Stewart, and switched back to guitar - as a permanent member, this time - in 2008.Born in Memphis, Tenn., in 1983, Myers became an avid guitarist at age 13 and was strongly influenced by Jimi Hendrix, Jimmy Page, Stevie Ray Vaughan and others in that vein. He was a Beale Street regular and internationally touring blues guitarist by age 14, and had already recorded a pair of albums with the Zack Myers Band before joining Shinedown. "I've been going to rock'n'roll shows and listening to rock'n'roll since I can remember, along with blues and soul music," Myers said. "Well, then I started playing guitar at 13, and then at 14 the next thing I knew I had a manager, a record deal and a band." Myers still plays in the longstanding trio he founded, the Fairwell, but his main focus r...

View Artists Profile