The KT88 fits a standard eight-pin octal socket and has similar pinout and applications as the 6L6 and EL34. Specifically designed for audio amplification, the KT88 has higher plate power and voltage ratings than the American6550. It is one of the largest tubes in its class and can handle significantly higher plate voltages than similar tubes, up to 800 volts. A KT88 push-pull pair in class AB1 fixed bias is capable of 100 watts of output with 2.5% total harmonic distortion or up to about 50W at low distortion in hi-fi applications. The transmitting tubes TT21 and TT22 have almost identical transfer characteristics to KT88 but a different pinout, and by virtue of their anode being connected to the top cap have a higher plate voltage rating (1.25 kilovolt) and a higher power output capability of 200 watts in class AB1 push–pull.[1]
The screen grid is sometimes tied to the anode so that it becomes effectively a triode with a lower maximum power output.
Historyedit
The KT88 was introduced by GEC in 1956 as a larger variant of the KT66. It was manufactured in the U.K. by the MOV (Marconi-Osram Valve) subsidiary of G.E.C, also labelled as IEC/Mullard, and, in the U.S., Genalex Gold Lion. [2]
Four KT88s installed and powered.
As of 2022, KT88 valves are produced by New Sensor Corporation (Genalex Gold Lion[3] and Electro-Harmonix brands) in Saratov, Russia, JJ Electronic[4] in Čadca, Slovakia and Hengyang Electronics[5] (Psvane brand) at former Guiguang factory in Foshan, China.
NOS examples in good condition are extremely rare. Due to its availability and characteristics, the KT88 is popular in hi-fi production amplifiers.
Historically, it has been far more popular with high fidelity stereo manufacturers than guitar amplifier builders, given its characteristics of high-power and low-distortion. Due to these characteristics, it is regularly used to replace 6550 tubes by end users seeking a guitar amplifier tone with less distortion.[6] Some of the amplifiers which shipped with the KT88 power tube include the Hiwatt, Marshall Major, and some Ampeg models.[7]
kt88, beam, tetrode, kinkless, tetrode, hence, vacuum, tube, audio, amplification, labelled, made, classificationbeam, power, tetrodeserviceclass, amplifier, single, ended, class, amplifier, push, pull, cathodecathode, typeindirectly, heatedheater, voltage6, 3. The KT88 is a beam tetrode kinkless tetrode hence KT vacuum tube for audio amplification KT88KT88 labelled G E C made by GEC MOV in the U K ClassificationBeam power tetrodeServiceClass A amplifier single ended class AB amplifier push pull CathodeCathode typeIndirectly heatedHeater voltage6 3Heater current1 6 AAnodeMax dissipation Watts42 WMax voltage800Socket connectionsOctal base IO Pin 1 Not used Pin 2 Heater Pin 3 Anode plate Pin 4 Screen grid g2 Pin 5 Control grid g1 Pin 6 Not used Pin 7 Heater Pin 8 Cathode beam platesTypical class A amplifier operationAnode voltage250 VAnode current140 mAScreen voltage250 VBias voltage 15 VAnode resistance12 kilohmsTypical class AB amplifier operation Values are for two tubes Power output100 WAnode voltage600 VAnode current100 mAScreen voltage350 VBias voltage 45 class AB2 ReferencesSuper Radiotron Valve Manual Amalgamated Wireless Valve Co Australia June 1962 Radio Valve Data Eighth Ed Ilife Books Ltd London 1966 Contents 1 Features 2 History 3 Characteristics 4 See also 5 References 6 External linksFeatures editThe KT88 fits a standard eight pin octal socket and has similar pinout and applications as the 6L6 and EL34 Specifically designed for audio amplification the KT88 has higher plate power and voltage ratings than the American 6550 It is one of the largest tubes in its class and can handle significantly higher plate voltages than similar tubes up to 800 volts A KT88 push pull pair in class AB1 fixed bias is capable of 100 watts of output with 2 5 total harmonic distortion or up to about 50W at low distortion in hi fi applications The transmitting tubes TT21 and TT22 have almost identical transfer characteristics to KT88 but a different pinout and by virtue of their anode being connected to the top cap have a higher plate voltage rating 1 25 kilovolt and a higher power output capability of 200 watts in class AB1 push pull 1 The screen grid is sometimes tied to the anode so that it becomes effectively a triode with a lower maximum power output History editThe KT88 was introduced by GEC in 1956 as a larger variant of the KT66 It was manufactured in the U K by the MOV Marconi Osram Valve subsidiary of G E C also labelled as IEC Mullard and in the U S Genalex Gold Lion 2 nbsp Four KT88s installed and powered As of 2022 KT88 valves are produced by New Sensor Corporation Genalex Gold Lion 3 and Electro Harmonix brands in Saratov Russia JJ Electronic 4 in Cadca Slovakia and Hengyang Electronics 5 Psvane brand at former Guiguang factory in Foshan China NOS examples in good condition are extremely rare Due to its availability and characteristics the KT88 is popular in hi fi production amplifiers Historically it has been far more popular with high fidelity stereo manufacturers than guitar amplifier builders given its characteristics of high power and low distortion Due to these characteristics it is regularly used to replace 6550 tubes by end users seeking a guitar amplifier tone with less distortion 6 Some of the amplifiers which shipped with the KT88 power tube include the Hiwatt Marshall Major and some Ampeg models 7 Characteristics edit nbsp Anode characteristicsSee also editKT66 KT90 6L6 6CA7 EL34 6V6 807References edit https frank pocnet net sheets 086 k KT88 pdf KT88 Datasheet Barbour Eric 6550 KT88 Power Kings Part II PDF worldradiohistory com Vacuum Tube Valley Quarterly 2003 Issue 19 Retrieved 23 April 2021 Genalex Gold Lion KT88 New Sensor Corporation JJ KT88 JJ Electronic s r o Classic Series KT88C Changsha Hengyang Electronics Co Ltd Fliegler Ritchie Jon F Eiche 1993 Amps the other half of rock n roll Hal Leonard p 15 ISBN 978 0 7935 2411 2 Aspen Pittman 2003 The Tube Amp Book Backbeat pp 125 ISBN 978 0 87930 767 7 External links editReviews of KT88 tubes Tube Data Archive thousands of tube data sheets Retrieved from https en wikipedia org w index php title KT88 amp oldid 1140508163, wikipedia, wiki, book, books, library,
