1 high-impedance, unbalanced signal input, either XLR or 6.3 mm jack. 1 low impedance, balanced XLR output. 1 instrument loop-through output, 6.3 mm jack. Converts unbalanced line signals (e.g., from instruments) into balanced XLR output signals for connection to a mixing console. Switchable input attenuation: 0 dB, -20 dB, -40 dB. Ground lift switch to prevent signal interference and hum loops. Modern convex housing design with rubber corners for safe standing. Cables can be routed under the housing. Power supply via 9 V block battery (included).