The historic site of Jean Marc Plantefeve will change host, its old site will therefore no longer be accessible, here is the address of the new one
https://2adiy.ovh/
https://2adiy.ovh/
designer notes:
PS: the modern LSK170A can make way for the old Toshiba 2SK170GR, the modern Exicon can make way for the old Hitachi 2SK1058 and 2SJ162.
The ECX10N20 and ECX10P20 are like the 2SK1058 and 2SJ162, with slightly better characteristics. The S models are also stamped with a color band which allows a first N/P pairing even without measurement.
In the idea of an accepted non-zero distortion spectrum (gradient harmonics), it is not necessarily necessary to pair, but to measure to calculate the upstream polarization resistance.