The KT88 mav be used in pairs in either triode, pentode or ultra-linear push-pull circuits and this Supplement gives circuits and operating data for amplifiers giving outputs of 30 to 400 v,ratts in various conditions of operation. Electro-Harmonix KT88 Vacuum Tube High power kinkless-tetrode for use in amplifiers such as the Marshall Major. This tube is a favorite of audiophiles. Can be used in place of 6550 for a more "round" bass signature. A list of Valve Data Sheets and Application Notes and links to others sites with such information. ... KT88. GEC Data sheet issue 5 1974 ... I have seen so far ~ They ... Well on a whim today I pull up the actual Tung-Sol spec sheet on “franks electron tube data” website and low and behold Tung-Sol indicated their tubes had a rating of 42. Scratching my head I pulled up the original Genalex spec sheet for the KT-88 and its rated at 35 Watts. Some valves are not listed but are available, for example output valves like 12BY7, 6146, 807, 4cx250B, 4-400, 6CA7, 6V6, 6L6, 6CM5 KT88's etc are priced accordingly, and passed on to other Amateurs and AHRS members at our current cost. The cost of every purchase varies, so there are often a few choices and different costs for each valve needed. Text: ï»¿THE M-0 VALVE COMPANY LIMITED KT88 Grenalex BEAM TETRODE BRIEF DATA The KT88 has an,. amplifier. Two valves in Class AB1 give a continuous output of up to 100W. The KT88 is also suitable for use as a series valve in a stabilised power supply. The KT88 is a commercial version of the CV5220 and is similar to the 6550.