This kit can be used as a pre-module for a number of audio applications where the input signal is too weak. Applications as a microphone pre-amplifier or for level correction.
Specifications:

1. power supply: 10-30VDC / 10mA
2. adjustable output level: max. 40dB
3. frequency range: 20Hz to 20kHz ± 3dB
4. max. input signal: 40mV
5. PCB dimensions: 30 x 44mm / 1.2 x 1.7"

illustrated_assembly_manual_k1803_rev2.pdf

assembly_manual_k1803_rev1.pdf

resistor_colour_code.pdf

module_diy_kit_guide.pdf