Manley Force, 4-Channel Tube Microphone Preamplifier, Features of each Channel: 120 Hz High Pass Filter, Phase Invert, Input Attenuator (Variable Pad), Gain Selectable Gain LOW vs HIGH, LED Peak Meter, Direct-Input ¼" TS unbalanced (for guitars, bass, keyboards), Silent Input Level Control (Variable Input Pad), +48V Phantom Power switchable; Vacuum Tubes: 4 x 12AX7WA dual triodes, Connections: 4x XLR Input balanced, 4x XLR Output unbalanced, Dynamic Range: 118 dB @ LOW GAIN, 100 dB @ HI GAIN, build-in Power Supply, Housing: 19" 2HE