Groove Tubes Silver Series are tested and warranted to meet or exceed factory specifications.
Silver Series tubes are excellent for "normal" tube replacement applications and offer exceptional value.
Not recommended for the critical high gain V1 stages of high gain guitar amps, but perfect for the other less critical stages such as V2-V6 stages.
Country of origin: Russia
90 day warranty on power tubes, includes replacement of whole set if one tube goes bad. 180 day warranty for preamp tubes. 3 year warranty on SubstiTubes and Solid State Rectifier. Check with M-Audio for warranty on GT microphones.