This kit has been developed as pre-module for a number of audio applications where there is insufficient input signal. Applications as a microphone pre-amplifier or for level correction.Specifications:* power supply: 10-30V DC / 10mA* output impedance: 1Kohm* adjustable output level: max. 40dB* frequency range: 20Hz to 20kHz ± 3dB* max. input signal: 40mV* PCB dimensions: 1.2" x 1.7"