I expect the jFet/trimmer is for a dc feed to the TDA1541, being 2mA.
[I went through my pile a few days ago; similarly had a stacked AD844 I/V ]
Years ago I tried 3 or 4 piggybacked, but they got very hot. I don't know why. There is no oscillation or any side effect. They sound good. Just the temperature is a bit too high for me. Eventually, I moved to OPA861 I/V.
The quiescent current depends on the Vb voltage; like 8V supply is what I used as ideal in my build.
I forgot to report but i also tried ssms scheme from post #21 of this thread, to bias into class A.
Indeed it works as he suspected, all higher harmonics are greatly attenuated, and it doesnt seem to be harmful in damaging the chips (at least from my testing).
But the increase in H2 you get is much higher than the decrease for H3 and up, so overall distortion goes up (this was at least my finding).
So if you want to turn your AD844 into spectrum that would make a SET blush go ahead.
I already bruteforced mine solution with stacking so no need
Indeed it works as he suspected, all higher harmonics are greatly attenuated, and it doesnt seem to be harmful in damaging the chips (at least from my testing).
But the increase in H2 you get is much higher than the decrease for H3 and up, so overall distortion goes up (this was at least my finding).
So if you want to turn your AD844 into spectrum that would make a SET blush go ahead.
I already bruteforced mine solution with stacking so no need
How far do you want to 'clone'?
A basic diamond is like the LeClasse-A circuit by Hiraga, just use the feedback as input and ground the normal entrance, that can be a starting point. . . The bandwidth is about <2Hz-240kHz. [ Made one last week with a Jims Store pcb - he had a kit with matched transistors, the N and P all Hfe 481 and Vbe within 2%.]
A basic diamond is like the LeClasse-A circuit by Hiraga, just use the feedback as input and ground the normal entrance, that can be a starting point. . . The bandwidth is about <2Hz-240kHz. [ Made one last week with a Jims Store pcb - he had a kit with matched transistors, the N and P all Hfe 481 and Vbe within 2%.]
