Groove Tubes GT-KT88-SV Medium Power Amplifier Tube, Matched Quartet (4)

Exclusive GT design. This is the highest-output power tube in the 6550/KT88 family, with special heat dissipation wings on the plate that let it reach the same power specs as the original Gold Lion KT88 of the '60s. The best, most durable and most powerful tone in the family, with outstanding dynamic response and big bottom end. The definitive tube for bass amps, country, jazz, metal and any situation in which most of the tone shaping occurs in the preamp, pedals or effects. Amazing high-horsepower delivery of clean tone.

6550/KT88
One of the highest-output 8-pin pentodes available. Originally manufactured in the United States by G.E., it delivers 35 to 50 watts per tube and was original equipment in Ampeg SVT and Marshall amps during the '70s and early '80s. A big, clean, tight tube with amazing headroom and performance and great power and dynamics. A similar tubes is the KT88 (used by Sunn and others). The highest-output power tube in this family.

Power Tubes
These pass every Groove Tubes premium certification for micro phonics, hum, noise floor, physical operation and performance characteristics. They also analyze and match the gain-to-distortion ratio on a dynamic basis, assuring a powerful, singing tone that is rich in harmonics and balanced for longer sustain, wider frequency response and a more musical amplification experience. Quite simply the best 8-pin pentode tubes you can buy that are specifically designed and tested for musical instrument amplification. Sold as single tubes, matched duets, quartets and sextets. Standard equipment on Fender tube amps.

Groove Tubes power tubes are matched and rated in low, medium and high output levels. Most amp manufacturers bias their amps for tubes in the "medium" range and replacement of stock tubes frequently do not require re-biasing if "mediums" are purchased. For softer feel, quicker distortion and creamier tone, They suggest "lows"; for more dynamic headroom and tighter, quicker and harder overall response, They suggest "highs". Lows and highs are more likely to require re-biasing by a qualified service technician to meet your performance preferences.