2SK135 - 2SJ50 -12W

[buzz2]

Can you please give me your opinion on this old schematic?
I sincerely welcome any suggestions to further improve this schematic.

Thanks in advance to anyone who can help.

[AndrewT]

The 2sj50 is shown upside down.
These are Lateral mosFETs. Diodes seem an odd choice for generating the bias voltage.
This is an inverting topology. Is that what you want?
Maximum output is specified as 13.7Vpk.
Using +-24Vdc supplies for only 13.7Vpk seems odd.
No gate resistors.
DC coupled

This looks more like a "test" for students, "work out want is wrong and give your solutions".

[jez]

Originally Posted by AndrewT

The 2sj50 is shown upside down.
These are Lateral mosFETs. Diodes seem an odd choice for generating the bias voltage.
This is an inverting topology. Is that what you want?
Maximum output is specified as 13.7Vpk.
Using +-24Vdc supplies for only 13.7Vpk seems odd.
No gate resistors.
DC coupled

This looks more like a "test" for students, "work out want is wrong and give your solutions".

All agreed. Plus I doubt that the voltage drop across the 2 diodes would be enough to make it other than pure class B.
The rails to the op amp are a lower 21V BTW.

[buzz2]

Originally Posted by AndrewT

This looks more like a "test" for students, .

Andrew, this is old schematic from "Electronic-Life" Vol.12, 1988 [12w Fet Power Amplifier by Sakasegawa

[CBS240]

It is good for conceptual understanding, but as far as a practical circuit it is rubbish.