For Groove Tube questions relating to tubes only, please call Customer Support at 1-800-813-1634 x333 or email at KMCCustomerSupport@kmcmusic.com

For all other Groove Tube inquires relating to amplifiers, microphones etc., please call Fender Consumer Relations at 480-596-7195 or send an email to: consumerrelations@fender.com.

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Groove Tubes® USA Dealer List >>Acme Guitar Works

The GT Rating System Explained

Understanding the GT Tube Performance Rating System

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. Contact Groove Tubes if you have questions about which tube will work for your amplifier, or whether re-biasing is required.