https://www.diyaudio.com/community/threads/choked-singing-bush-special-one-for-purists-and-masochists.388480/
OK, this one long in making
I mean - have pcb files and everything for some time, basic functions confirmed but - as is my nature - never working by plan
Anyway - why Purists and Masochists?
List of reasons:
1. you really need properly made high quality choke; 100mH, no more than 0R5 winding resistance, declared for 3A5dc (big Tokin) or 2A5dc (small Tokin)
2. PSU - bummer - heavy filtration; CLC, or C then cap multiplier followed with heacy C cell, or fat switcher ..... most likely also followed (by choice or necessity) with some sort of high-pass filter and followed with fat C cell
3. this time ( even if evidently intended as option) - no Schade Mos Puck; simply too high Rout of part itself (even if normally or even heavy Schaded), resulting in uberfunny transfer function and THD way too high; now - with all my crummy chokes (yes, Plethora of them but all crummy) that's the situation; there is a possibility that Schaded option is viable and worthy if adequate quality choke is used, but that I can't confirm, nor I intend to purchase it, in any way or arrangement
4. looking at all above - simply - cost; you gain something with lesser volts involved (vs. say "regular" Singing Bush) thus lesser heat and lesser Donut and lesser voltage caps and lesser Aluminum in sinks...... but then main choke, PSU choke, yadayada....
5. yes, OPT is an option, for both shown iteration ( Big Tokin, small Tokin), don't have it, easy to try if you have one; same conditions as with choke - do not even try with cheaply made Iron
there are few more reasons, worthy of this list, but I'm lazy to think now .....
Anyway, usual set of introductory eye-pleasing files: