Our audio amplifier kit works very well; but if your input is a tape head; magnetic phono cartridge or electric mike; the input level may be too low to do the job. This small preamp can be used in these applications; plus; we have included a mike that may be used with the circuit. Power at 6V to 12V (current at 12V is 3mA; only 2mA at 9V). The gain is more than 40 dB.