JJ Electronic - COMPANY PROFILE
In 1994, JJ Electronic started with the production of three types of tubes. Today, we offer an assortment of more than 40 types of tubes. In 1999, capacitors and tube amplifiers were added to the JJ Electronic manufacturing program.
JJ Electronic began the development and production of vacuum tubes in 1994. Since that time, we have successfully introduced 17 more tubes into production. In 1999 we began the production of tube amplifiers. The first model was the JJ322, a class A amplifier, powered by four JJ Electronic 300B triodes. Today, we manufacture four power amplifier and two preamplifier models. All these products have been safety certified for the use around the world. Also in 1999, we introduced the production of electrolytic capacitors. Three years later, we started production of polypropylene capacitors. These capacitors received certification from international test authorities. We started our company with about 700 sq meter production facilities; today JJ Electronic owns more than 12000 sq meters of production floor.
All materials used in the manufacturing of our tubes comply with the most stringent quality requirements.
In tube manufacturing, the fundamental requisite for the best production results is to maintain as high mechanical precision for assembly as possible. JJ Electronic uses assembly precision of no more than 0.02 mm.
Before they are assembled, all parts are thoroughly cleaned using such methods as the ultrasonic bath, chemical cleaning or annealing in an inert gas atmosphere (hydrogen, nitrogen).
A thorough inspection is performed on every component of the tube internal system before assembly. Assembled systems are then sent to sealing in a glass envelope. During the sealing procedure, the temperature of the glass pass-through joints must be controlled and joints are gradually tempered to relieve the inherent thermal stress.
Next, the assembled glass envelopes are evacuated by mechanical and diffusion vacuum pumps. During this process, the cathode emission coating is activated. All internal parts are heated by a high frequency heater and any spurious dust particles are evacuated. Finally, the getter rings are activated, while they absorb any residual gas inside the glass envelope of the tube.
Every tube is then electrically tested for all parameters which are the key to a flawless operation and a great sound. Specifically, these parameters include: leakage characteristics, internal vacuum level, cathode emission capability, filament voltage and current, anode current saturation level, microphony and others.
Every month, random samples are taken from the production line in order to perform a life time test of 5000 hours under nominal conditions or 1000 hours at maximum specified ratings.