The EC7 multi-pin cable is a replacement for the cable that comes as an included accessory for the Groove Tubes Velo 8T Ribbon Microphone.
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.