API 3124mb+, w/ stereo mixer plus transformer bal outputs, 4 channel preamp, same microphone preamp circuit that is used in all API consoles, RE-115K microfontransformer and outputtransformer, channelswitches: 48V Phantom, Phase, Pad -20dB, Mic/Line, on the front High-Z unbal. input for guitar or bass, (up to +22dB), output up to +30dBm, channelgain 65dB, in/outs backside XLR,