S simonbramble Active Member May 23, 2012 #2 it is a cheap (read cheap and nasty) audio amplifier. The microphone input gets amplified by Q1, Q2, Q3 with negative feedback via R2. C1, C2, C3 provide ac coupling (so the dc is not amplified). P1 and SW1 is a combined switch and volume control
it is a cheap (read cheap and nasty) audio amplifier. The microphone input gets amplified by Q1, Q2, Q3 with negative feedback via R2. C1, C2, C3 provide ac coupling (so the dc is not amplified). P1 and SW1 is a combined switch and volume control