how do you clculate r20 and r24 in function of k170 idss?
But you can build the mirrored J2 (UDNeSS) and run it as an inverted amp.
Not possible with the mirrored F8.
Patrick
Another interesting option for the F8/Aleph topology would be using an RF LDMOS such as the RD100HHF1 or MRF151A at the lower FET. Very nice package with low thermal resistance but needs RF know how and at least high MHz scope to assure stability and no oscillation.
I am not sure, I just take it as a normal voltage divider for negative feedback voltage reference although its a CFA.
I am trying to simulate a higher voltage version with cascoded input stage and "individual biased" lower mosfets which I guess matching the lower mosfets is not crucial here. Just the higher side mosfet has more stress to work alone.
PS: I am still dreaming to have a dynamic biasing for it to work with lower impedance loads with higher efficiency...
2 new objectives into the circuit:
A. Dynamic biasing adjustor:
I am trying with two optocouplers to bias the circuit, making it to work better with low impedance loads. Instead of Single Ended with only 15w4ohm, its now beyond 35w4ohm. Still figuring a better way...
B. Transimpedance Output like Valve amp coupled with transformer:
Taking the speaker impedance feedback into the circuits. When the impedance increase, the output increase, so the fullrange speakers will sing like a Vshape EQ, hopefully.
Pushing the single ended f8 to work into Class AB region, it can deliver up to 50Wrms into 4ohm. 🤓
There is an error in this picture, but I don't know much about the circuit and can't find the reason. Friends, please take a look.
This is just for interest and DIY fun. I bought other people's imitations on the platform, but I still like authentic products. The original picture was also taken on the XX Voice platform, which was published by friends in Malaysia.
