Choctaw - 10 Watt Amplifier, 1 Opamp + 2 MOSFET

Here is my latest final Choctaw.
It has lower distortion and is what you should build.

Choctaw_21 Final.jpg
 
could i use a simpler op amp such us ne5534?
Is it possible to use IRFP240 and IRFP9240 instead of ECX10N20 and ECX10P20?
I do not recommend NE5534 or IRFP240.
Because they will have less than 10 Watt output.
Maybe only 5-6 Watt.
However there are several opamps that can be used.
They should preferably be RRO, rail to rail output. And unity gain stable.
Probably OPA134 (OPA2134) can be used.
 
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Is it possible to use IRFP240 and IRFP9240 instead of ECX10N20 and ECX10P20?
you have to work with a VBE multiplier because the Vgs at EXC starts at 1V and you get 1Amps drain current. IRFP240 need about 2-4V VGS to be in the linear area to get about 500 mA.
so you have to "set" the VGS higher and must keep that stable because Vertical MOSFET´s are negative tempco !!--> thermal runaway!!!
look at the datasheets at the input characteristics.

EXC...

1731922758610.png


IRFP240
1731922799764.png
 
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