MJK's SSSchadeode

[sulcorebutia]

Recently I have purchased some DN2540 from mouser for CCS project. When searching among forum's post for further information, I accidentally encountered MJK's enlightening idea of Schadeode idea:

Most linear triode-strapped pentode

Schadeode

And the following Soild-State Schadeode is the most fascinating:


However, it doesn't seems I can get IXGH6N170A and IXTP01N100D outside USA by any chance. As I have some tube transformers & DN2540 sitting around, why not give it a try? A quick simulation yield the following:



4W output power on 8 ohm loading with 0.31% Total Harmonic Distortion, not bad

So, here comes the questions:

1)M1 is biased to 14.5W at idle, is it too risky to run M1 close to its maximum power dissipation 15W?

2)If we target output power for 3W, any better operating points for both M1 and M2?

3)How to bias M1 so that we can incorporate the B+ to cathode capacitor like MJk's original circuit?

4)I notice that if the input of M2 is lower than -1.2V, M1's current will go crazy and possibly burn itself out , how can we limit the maximum current of M1? Shall we add a CCS for M1? or cascaded M1 with another DN2540?

Any input, any discussions are more then welcome!


P.S. The attached zip file contains the LTspice circuit, mosfet library for you to tweak of