About TAD premium tubes:
TAD does all TAD Tube quality control processing in-house under strict control of our technical staff. Our techs which are also musicians and guitar players, developed and constructed our custom tube testing systems and aging rigs to run tubes in real amplifier circuits and operation conditions.
For TAD, real tube quality control is way more than just a simple test. Before a TAD Tube gets accepted at all we perform extensive sample evaluation testing for consistency, power test, shock resistance test, soak test (long term operation at full power) and of course a musical test in known amplifiers to learn about its sound character in different styles. The main tests are made after a propper pre-aging to stabilize the cathode emission. While most tube test equipment does work at 250V as a maximum we built our test rig to operate at voltages of 360 to 600V depending on the tubes being tested. Every TAD Tube is tested by our qualified staff. Each pentode is inspected,tapped while operating and listened for noise floor, hum and odd noise.