SUBSTI-TUBE 1A 6SN7 to 12AT7 (includes GT-12AT7 tube)
Groove Tubes Substi-Tubes allow the replacement of octal type preamp tubes with the more common and higher quality 9-pin miniatures by properly mating a female 9-pin socket to an 8-pin plug.
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.