Category Archives: Pre Amplifier



Pre-Amp + Tone Control with TDA1524A

This is a low noise and distortion pre-amplifier and tone control circuit in one module. Using a special IC TDA1524A, this simple circuit is easy to build and will drive most of power amplifier. Schematic diagram:

Low Noise Portable Mic Preamp

This is the circuit diagram of portable mic preamp. This circuit consumes low current supply (about 2mA), so will have a long battery life for supplying the circuit. Harmonic distortion is about 0.1% @ 1V RMS output for all frequencies. Maximum input voltage (level control cursor set at maximum) = 25mV RMS. Maximum input voltage… Read More »

HiFi Audio Pre-amp

This is a HiFi pre-amplifier circuit diagram with low noise output. Very wide range frequency from about 10Hz until up to 100Khz  will be gained by this preamplifier for maximum audio performance. This circuit uses BC550C / BC560C transistors as active component. Use regulated power supply 15VDC for maximum result.

Low Impedance Microphone Amplifier

This is the circuit diagram of low impedance microphone amplifier. The circuit designed for use with low impedance (~200 ohm) microphones. It will work with regulated voltages between 6-30VDC. If you don’t build the impedance adapter part with T1, you get a microphone amplifier circuit for higher impedance microphones. In this case, you should directly… Read More »