Wiring circuit

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Class A Power Amplifier by IRF530N 78L05

This is the best design I have came up so far!
I use two 6x6x4cm heatsinks per channel. Power supply is unregulated (just transformer, diode bridge and capacitors) but I cannot hear anything even when I put my ear within few centimeters of the loudspeaker. Opamp has very good power supply rejection ratio. I’ve tried to keep everything as simple as possible and basically LM317 would be just one extra opamp

If you are looking for better sound, get separate regulated low power supply just for the U1 opamp, something like +-15V at 100-200 mA.
I have also used one LM7805 to get bias for both channels – you may want to use two separate 7805 in a final amp to get better channel separation. R2 pot is anything from 500 to 50k. I have used 22k.