Double Bass preamp system - including: 1x bass bridge w/ built-in 3 transducers(1 bass-end, 1 high-end and 1 under saddle) connected to a 3-pin XLRm output plug + 1x "Statement" amplification/ mixer unit featuring: Mix1(bridge signal) and Mix2(top signal) controls/ main volume/ footswitchable mute/ XLR input/Line output(6.3 mm phone jack )/ Mic output(balanced XLR)/ ground switch - Built-in high-pass filter to cut hum and ambient noise - Power supply: 9 Volts battery or 12 Vdc external AC/DC adaptor( both not included), or standard 48 Vdc(phantom).