New Plate Current Matched Sextet of Tung-Sol KT120 Vacuum Tubes The KT120 is an incredible tube. Essentially a KT88 / 6550 on steroids, they are capable of pushing 150 watts per pair of clean power in a push-pull configuration. Because of the high wattage, these have become a favorite among bass players and guitarists who want to max out their clean headroom and volume. One of the very few vacuum tubes designed in the modern era, they manage to keep the same warmth and feel of other vintage tubes. These are very close to the original Tung-Sol 6550s in terms of tone and reliability.