Audio circuit diagrams

24 Watt Class A Amplifier

A 24 Watt Class A Amplifier made from discrete semiconductors, built and tested by Marc Klynhans from South Africa.

The GEM Class-A/AB Amplifier

Dynamic Microphone Preamp

A low noise pre-amplifier suitable for amplifying dynamic microphones with 200 to 600 ohm output impedance.

Mini Guitar/Bass Amplifier

Output power: 6W into 4 Ohm load. FET input stage - Passive Tone Control

Op-Amp Mic Preamp

A high quality microphone preamplifier using a single power supply, suitable for dynamic or electret microphones. The op-amp used can be any low noise, high performance type, e.g. NE5534,TL071, OPA 371 etc.

200mW Stereo Amplifier

A small battery driven amplifier with 200mW output. This is a suitable amplifier for portable radios and other battery powered equipment.

Guitar Preamp

A pre-amplifier for electric guitars. The guitar pickup is high impedance, therefore good quality screened cable must be used between guitar pickup and the preamp.

Stereo Line Driver

A stereo line driver for feeding long cables or buffering an audio source.

Audio Indicator

This circuit can be used to remotely monitor a loudspeaker, alarm, or audio source for presence of an audio waveform. It can also be directly connected across loudspeaker terminals used as a peak indicator.

2 Watt Amplifier

A 2 Watt audio amplifier made from discrete components.