The "Blues" TubeGT-12AU7 tubes pass every Groove Tubes premium certification for microphonics, hum, physical characteristics and function. Quite simply the best 9-pin triode preamp tubes you can buy — specifically designed and tested for musical instrument amplification and standard equipment on Fender® amps. Outstanding and consistent performance for mixing and matching to get a signature tone from your amp.
Our lowest-gain preamp tube. Can sub for a 12AX7 for lower gain and to produce a very creamy, warm tone. Great for harp or blues when softer, more compressed distortion at lower volumes is desired. Very low gain and very mellow output.