This efficient MOSFET power audio amplifier based on IRF530, IRF9530HEXFETs and BC550C NPN transistor provides about 18W into 8 Ω speakers and up to 30W into 4 Ω speakers with a total harmonic distortion (THD) of less than 0,08% at 1 kHz. This performance is gained by using only some resistors and capacitors except the transistors. So this is a really easy to build MOSFET amplifier.
You must build two of them to use the amplifier in stereo mode.
After assembling the parts, a list of instructions to follow are given in the original circuit page
The circuit requires regulated 40V power supply. The implementation of such a single rail DC power supply and a preamplifier stage are also given in the project page.
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