Active Direct Box The Mackie MDB-1A is an active direct box designed to connect a single instrument such as a guitar, bass, or keyboard to a microphone preamp for musicians and audio engineers in recording sessions, houses of worship, and live stage applications. It converts a high-impedance, instrument-level signal via its 1/4" TS unbalanced input to a low-impedance, mic-level output via its balanced XLR 3-pin jack. A 1/4" thru jack allows simultaneous connection to an amplifier or pedalboard. A -20 dB pad reduces the input level to prevent distortion when using a high-gain source, and the ground-lift switch inhibits hum caused by ground loops. Additionally, there are switches for polarity and a 120 Hz high-pass filter. The Merge function allows the Thru jack to be used as a second, simultaneous input. Due to its active design, the MDB-1A operates on phantom power. A sturdy steel chassis enables confident use in the studio or on the road.Features: Connect an instrument such as a guitar, bass, or keyboard to a microphone preamp Converts a high-impedance, unbalanced 1/4" input to a low-impedance, balanced XLR mic-level output 1/4" thru jack for routing to an amplifier -20 dB pad prevents overloading when accepting signal from a loud source Ground-lift switch minimizes hum Active design operates on phantom power Specifications: Type: Active Input Connections: 1 x 1/4" TS unbalanced Output Connectors: 1 x 1/4" TS unbalanced 1 x XLR 3-pin balanced Input Impedance: 330 kOhms unbalanced Output Impedance: 150 Ohms balanced Impedance Ratio: 2200:1 Pad: -20 dB High-Pass Filter: 120 Hz Controls: Pad Ground-lift switch Merge Low-cut switch Polarity Frequency Response: 20 Hz to 20 kHz (±0.5 dB) Signal to Noise Ratio: 90 dB Dynamic Range: 130 dB Total Harmonic Distortion: 0.02% at 1 kHz Power Requirement: 48 VDC phantom power Current:
