This is what you said "sunshine" and to my point, you are essentially making a different amp. The one who doesn't have any decent tech knowledge is you. I have designed many amplifiers, discreet and on integrated circuits, hence why what you post sounds so ridiculous to me. You can't simply change an output stage on a power stage between MOSFET and BJT. It don't work that way sunshine. Now if you had any tech knowledge you would know:
Actual "tech", not a cut and paste tech ....
- Typical output stages have 0 voltage gain so quoting in this case that they have higher voltage gain is silly.
- In an amplifier, output current is mainly a function of thermal limitations. I can cheaply buy a 100A MOSFET, more than enough for almost any power level so to say a BJT can handle higher current is just wrong. That has not been true for decades.
- Output impedance is a function of device and circuit, not just the device so making a claim a BJT has lower output impedance is specious. You can try to make the claim there is less difference in base/emitter voltage compared to gate/drain voltage over loading, but higher biasing of the output stage with modern FETs can negate that advantage. As well a BJT requires a very high current to drive it and that current gain is variable w.r.t. output current leading to distortion inducing mechanisms elsewhere in the amplifier that a FET amp may not experience ..... And also why you cannot simply swap the output stage! ...and have it work properly.
Actual "tech", not a cut and paste tech ....
There’s a post a member put up a couple of weeks ago (go find it), who does mods for his customers, where he takes a Mosfet amp removes the complimentary N/P channel Mosfet output stage and replaces it with complimentary NPN/PNP Bi-Polar (BJT), and he and his customers say it all in their description of the sound change.