Universal Mono Pre-Amplifier Kit - K1803 by Velleman. Intermediate level soldering kit Power supply: 10-30V DC / 10mA (not incl.) Adjustable output level: max. 40dB. Max. input signal: 40mV Frequency range: 20Hz to 20kHz  3dB PCB dimensions: 1.2 x 1.7" Electronic kit. Soldering and assembly required.