6550 Power Valve for Guitar Amplifier (Alt KT88)

The 6550 (KT88) Power Valve for Guitar Amplifier is a high power beam tetrode vacuum tube used mainly as an audio power amplifier. The 6550 was developed in Russia in 1955 by Tung-Sol. The 6550 (kt88) power valve is often found in valve bass guitar amplifiers by makers like such as Marshall bass amps , Ampeg bass amps and the Leslie rotary speaker system. You can buy the 6550 (KT88) Power Valve for Guitar Amplifier below however they are mostly used in, 6550 matched pairs, 6550 matched quads, 6550 matched sextet and complete amplifier replacement valve kits. Use the links at the bottom of the page to find your valve or amplifier.

BUY 6550 (KT88) Power Valve for Guitar Amplifier

Buy 6550 Valve Matched Sets

About the 6550 (KT88) Power Valve for Guitar Amplifier

The 6550 (KT88) Power Valve for Guitar Amplifier design is based on the popular 6L6 power valve. The 6550 was designed to have higher output power and better stability. It operates with a plate voltage of 600VDC, a screen voltage of 400VDC, and plate dissipation of 35 watts.

  • Manufacturer – Tung-Sol was founded as Tung-Sol Lamp Works Inc. in Newark, New Jersey in 1907. The company entered the electronics field in the 1920s. In time they established themselves as leaders in the development and production of vacuum tubes, with their main competition including RCA and Sylvania. Tung-Sol Electric Inc was acquired by Wagner Electric, which itself merged into Studebaker-Worthington in 1967. Tung-Sol was privately held and run like a laboratory. The Tung-Sol brand name is now owned by the New Sensor Corporation, the same company that owns the brands Sovtek and Electro-Harmonix.
  • Alternatives – The KT88, KT90, and 6550, although not identical, are often interchangeable, dependent on external circuit parameters. The glass envelope for the 6550 (KT88) tube was originally wider in the middle than at the top and bottom, but a straight-sided design was later introduced by GE and Philips.

More Valve Products to Consider

Is your Guitar Amplifier not performing like it did when new? Has the output sound begun to degrade and break up? Are you experiencing additional noise and distortion? If yes, then it is time to consider replacing some or all of the valves in your guitar amplifier. Guitar amplifier valves (or tubes as they are known in the USA) are robust and will work for many hours. Performance will be affected by mistreating them or allowing them to overheat. Generally the performance of vacuum tubes starts to degrades with the amount of time they are used and up to 1000 hours is typically the optimum life of a valve or tube. If the performance of your amplifier is failing then it is likely that some or all of the valves need replacement.

When replacing guitar amplifier valves it is best to use matched pairs as this will ensure the valves last as long as possible with the best sound quality. We have a full range of replacement guitar amplifier valves and matched sets available for the most popular amplifier types – see the links above.