TAD 7025 Highgrade Premium RT010

TAD carries out quality control for all TAD tubes under the strict supervision of its technicians.
For this purpose, they have developed and built their own test systems that allow them to test tubes in actual amplifier circuits under real conditions with voltages of up to 600 V.

For TAD, however, real tube quality control is much more than just testing.
Before a tube can be accepted as a TAD tube, it must pass extensive sample series tests and later random tests again and again.
These include
testing for consistent parameters, both mechanically and electrically, performance tests, continuous full load tests, mechanical load capacity and, of course, the sound aspects in various well-known amplifiers.

The actual tests require a proper burn-in of the tubes to ensure uniform emission of the cathode.
As this is not usually the case at the factory, TAD has developed its own burn-in system.
Every TAD tube is tested by qualified inspectors.
Each pentode undergoes an optical test, is tapped for microphony during operation and at the same time monitored for noise, hum and interference via a monitor system.
Only then are the parameters measured and matched according to Ia (PC) and Gm (TC).
Each test series comprises 400-500 tubes in order to achieve the narrow tolerances of 0.5 mA (PC).

All TAD tubes and boxes are labeled with PC and TC values and are given a serial number to identify each tube that has been tested.
The quality of the selection and matching of the tubes is constantly checked by TAD themselves, as their service workshop uses TAD tubes on a daily basis and they also install them in TAD amp kits themselves.
TAD therefore has a complete quality assurance system for amplifier tubes.