2x NOS BlackPlate 6L6GC RealisticJapan PowerTubes /VintageAudio KT66 EL37
Introduced in 1959, the revered high power 6l6gc features improved plate dissipation over the original g/ga/gb series 6l6. full mutual gm conductance test, pristine nos: 111/110 % gm (65 % min good).