Key Features
- Connect an Instrument to a Mic Input
- Converts Unbalanced to Balanced
- Converts High Impedance to Low Impedance
- 1/4" Unbalanced Input
- 1/4" Thru Jack
- XLR Balanced Output
- Switchable Pad Prevents Overloading
- Ground-Lift Switch Minimizes Hum
- Merge, Low-Cut, & Polarity Switches
- Operates on Phantom Power
Description
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: <4 mA DC
- Construction Material: Heavy-gauge steel chassis
- Dimensions (H x W x D): 1.5 x 3.4 x 5.8" / 38 x 86 x 147 mm
- Weight: 0.8 lb / 0.4 kg