This listing is for four pieces of genuine Toshiba audio power MOSFET 2SK405-Y/2SJ115-Y. These parts are already obsoleted so they are hard-to-find parts.
Toshiba power mosfets are superior to IR/Vishay counterparts in terms of :
1. linearity for lower drain current operation,
2. Vgs variation against working temperature.
The 2 pieces of N-channel and 2 pieces of P-channel are tightly Vgs matched respectively to a variance of +/-50mV.
The matching was done at a drain current of 0.8A to ensure the transistors are well matched for either class AB or class A amplifiers.
We use our in-house designed fixture for the matching. The circuit is as the picture below with drain current running at 1A or higher and use Agilent( now Keysight) 34401A six and a half digit multimeter to do accurate and fast response measurement.
This is our standard method for matching of power mosfets.
Those using simplistic transistor tester ( such as MK-328 transistor tester) cannot give the right results. The 006P 9V battery in the transistor tester is unable to give enough current even to turn on the MOSFETs !
