copy/paste from Big DiyA
Preceding thread here : https://www.diyaudio.com/community/threads/zms-2sk2087c-musings-phase-one-sissysit-as-cradle.386654/
What was logical precursor/reason to dust off schematic I'm having for some time and to implement it in form of new pcbs, arranged so both Tokin Pucks and Tokin 2SK2087 can be used
Novelty - reason enough for playing with, is full DC connection from input to output, and also current-mirrors based biasing circuit
Nota Bene that DC connection between FE and OS is typical Cheating Papaway - anyway, see it by yourself, draw your own conclusions
Changes vs. SissySIT R.3 - none regarding sound (had my time with farting elephants, life is simpler after that), even steadier output DC Offset and Iq stability, vs. time, temperature, mains fluctuation
As I can see, there is some better drive (shown in clipping level for Big One) but these differences are strictly academic ones, sorta pity that this amp is never going to be considered by Audiophools, having all pizzas for great Drek-selling Story :devilr:
as always, basic pics first