Refer Silicon Chip July 1994 This tiny preamp was specifically designed to be used with the ³Champ² amplifier KC-5152. Unless you have a signal of sufficient amplitude the ³Champ² will not produce its maximum power output. The ³Pre-Champ² is the answer with a gain in excess of 40dB, which is more than enough for most applications. You can vary the gain by changing a resistor and theres even provision on the PCB for an electret microphone. Power requirement 6-12VDC. Kit includes PCB and electronic components.