TAD 7025 WA Highgrade Premium RT080

TAD performs quality control for all TAD tubes under strict supervision of their technicians. For this purpose, they have specially designed and built test systems that allow tubes to be tested in actual amplifier circuits under real conditions with voltage up to 600V. However, for TAD, true 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, repeated random tests. These include among other things, testing for consistent parameters, mechanically as well as electrically, performance tests, continuous full load tests, mechanical load capacity and of course the sonic aspects in various known amplifiers. The actual tests require proper burn-in of the tubes to ensure consistent emission from the cathode. Since this is usually not the case from the factory, TAD has developed its own burn-in system. Each TAD tube is tested by qualified inspectors. Each pentode undergoes an optical inspection, is tapped for microphonics while in operation, and at the same time is also listened to via a monitor system for noise, hum, and interference. Only then are the parameters measured and matched according to Ia (PC) and Gm (TC). Each test series includes 400-500 tubes to achieve the tight tolerances of 0.5 mA (PC). All TAD tubes and boxes are labeled with PC and TC values and given a serial number to identify each tube that was tested. The quality of the selection and matching of the tubes are permanently checked by TAD themselves, as their service workshop uses TAD tubes every day and they also install them in TAD amp kits themselves. Thus, TAD has a complete quality assurance system for amplifier tubes.