A.F. BEAM PENTODE - KT77 is a beam power pentode with octal base. It can be used in most EL34 amplifiers. It has more power, fatter bass and more headroom than the EL34 and E34L while providing very detailed tones.

JJ Electronic is a world-renowned manufacturer of vacuum tubes, electrolytic capacitors and high-end audio amplifiers. Founded in 1993 by Jan Jurco, a small garage business grew to become a well known and respected in music industry.

JJ vacuum tubes and capacitors are widely used in guitar and audio amplifiers, recording studio equipment and in a variety of applications for audiophiles.
 
We offer more than 35 preamp, power and rectifier tubes. All tubes were developed by our in-house research and engineering teams. In addition, we manufacture electrolytic capacitors for different voltages, both radial and axial types. Today, our manufacturing program also includes a number of high-end audio and guitar tube amplifiers. All of our products are the result of diligent research in the audio field and its continual application into manufacturing.

We are proud of the fact that every component used in our vacuum tube production is manufactured in-house. This enables us to have complete quality control of every part of the manufacturing process. All materials used in tube and capacitor production undergo a meticulous cleaning process such as ultrasonic cleaning, annealing in protective atmosphere and reactive rinsing. The assembly process is carried out by a combination of meticulous manual operations and state-of-the-art production processes.

All vacuum tubes and capacitors go through an extended burn-in period to ensure superior stability. A rigorous final test for tubes and capacitors verifies every important parameter. In particular, the parameters for flawless tube functioning include insulation characteristics, vacuum level, cathode emission efficiency, filament voltage, plate currents, and microphonics. The quality control process includes several thousand hours of reliability testing on samples of tubes and capacitors.

By using our tubes and capacitors in our own line of audio amplifiers, we continually verify their quality and performance in the practical applications.