There are only 2 major manufacturers of vacuum tubes in production today that are available for electric guitar and bass amplifiers. Many other companies "relabel" these tubes with their own logo, but a few of them like Tube Amp Doctor, ARS, and Mesa Boogie do extensive testing and matching before boxing and shipping to the customer.
1. The JJ/Tesla plant founded in Czechoslovakia, has been around since the 1920's but are now building in the Slovak Republic.
2. The Xpo-pul plant in Saratov, Russia, builds for Mike Matthews, CEO of Electro Harmonix. He has the rights to Sovtek, Tung-Sol, Genelux, Electro Harmonix, Svetlana, and Mullard.
$ 265.00
A.F. BEAM PENTODE. KT88 is a beam output pentode with an octal base and power of 42W. Very powerful, with strong bass and very bright highs. It can also be...
$ 75.00
POWER PENTODE 7591 S is an octal power pentode with power of 19W. Special tube for some types of vintage amplifiers.