This simple circuit of low power with an LM386 includes the highly sensitive audio preamplifier whose gain is controlled in the 100k pot. The volume is controlled in 10k pot. The source must be symmetrical with at least 300 mA of current. Signal input cables must be shielded because of the great sensitivity of the circuit. Among the applications suggest a stage of highly sensitive audio signals or step for experimental receivers. The power will be of the order of a few hundred milliwatts.
