💡 Use mica insulators and thermal grease when mounting 2N3055s to a shared metal heatsink. Fusing: Place 2A fuses on both the +Vpositive cap V −Vnegative cap V rails to protect the transistors from shorts.
A small-signal transistor (like a BC547 or 2N2222) acts as the initial pre-amp/differential pair. The BD139 and BD140 transistors form a complementary pair. 2n3055 Audio Amp Schematic
potentiometer is usually placed here to adjust (to prevent crossover distortion). Output Stage (The 2N3055s) 💡 Use mica insulators and thermal grease when
This stabilizes the gain and reduces total harmonic distortion (THD). Safety & Build Tips The BD139 and BD140 transistors form a complementary pair
as these transistors generate significant heat during operation. emitter resistors to provide thermal stability. Feedback Loop A resistor (typically ) connects the output back to the input stage.
The collectors of the 2N3055s are connected to the positive and negative power rails.