MACKIE MDB-1A ACTIVE DIRECT BOX

Product Highlights

• 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, and Polarity Switches
• Operates on Phantom Power

2-channel DI box/splitter, passive Converts 2 separate unbalanced line inputs (e.g. instruments) into 2 balanced XLR outputs for connecting a mixer Switchable to split mode (input 1 routes the signal to both outputs) Switchable input attenuation: 0 dB, -20 dB, -40 dB Ground-lift switch eliminates ground loop problems 2 signal inputs via XLR/jack combo connectors 2 low-impedance XLR outputs Modern convex housing design Full rubber housing corners for safe operation Cables can be routed under the housing

The Stewart ADB-1 is a single channel active direct box that allows an unbalanced source to
directly feed a balanced input. Musical instruments, tape recorders, VCRs and sound projectors
can be run "direct" to the mixing console, avoiding unnecessary degradation of sound quality.
The ADB-1 operates on either phantom power or a 9-volt battery.

FEATURES:
Flat response
Low distortion
Low noise
Wide dynamic range
No transformer
RF protection on input and output
Switchable ground isolation
Flush mounted slide switches

Phantom or battery powered in a rugged steel chassis, with separate Speaker Level input connector
 
The ARX DI-PLUS represents another major step forward in active direct boxes. Packaged in
a single channel stand-alone format, the DI-PLUS represents a fresh look at active D.I. concepts.
Precision engineered
Ultra quiet, ultra clean circuitry delivers maximum headroom whatever the signal. Premium grade
components, plus an all-steel chassis gives excellent hum and noise specifications and superb
audio quality in a tough, roadworthy package.
Level control
The DI-PLUS features a Normal gain high impedance unbalanced input on the front panel, running to
a balanced XLR output on the rear. There is also a separate -40dB Speaker Level input for signal coming
from the External (auxiliary) speaker output of an amplifier. A a global Pad switch drops both the normal
input and the speaker input by a further 20dB, making it suitable for all applications, from the softest
keyboard to the hottest broadcast levels.
 
Battery compartment
The revolutionary simple 'clamshell' action of the DI-PLUS battery compartment makes battery changing
extremely easy, even on the darkest stages.
A 9v alkaline battery snaps into a PCB mounted battery holder for fast, secure location. No fragile battery
clip leads to break, no tools required, no screws to lose. Production crew heaven!
 
Automatic Phantom switching
The DI-PLUS will automatically switch itself to the console's own Phantom Power, if available, and an LED
will indicate this mode. Turn the Phantom Power off and it will instantly revert back to battery mode.
Rugged all-steel case
A lot of direct boxes are fitted into brittle cast alloy cases. Not this one! The tough all-steel inner and outer
chassis of the DI-PLUS provide excellent RF/EMF shielding while making it a sturdy, heavy duty unit that is
hard to dislodge, and hard to leave behind.
 
Rear panel showing XLR connector, ground lift switch, and captive screw for opening up the unit
for battery changing
 
Whether you're a Studio or Live Sound engineer, installation contractor, or broadcast engineer, you want all
the dynamics and clarity of the original sound source transferred to the mixing console. The ARX DI-PLUS
provides a rugged, no-compromise solution to all direct injection and signal balancing requirements.
 
T E C H N I C A L  S P E C I F I C A T I O N S:
Max Input Level
+13 dB Phantom powered
+6 dB Battery powered
Input Impedance 1 Meg Ohm
Max Output Level
+17 dB 10K Ohm load Phantom powered
+12 dB 10K Ohm load Battery powered
+11 dB 600 Ohm load Phantom powered
+12 dB 600 Ohm load Battery powered
Output Impedance 680 Ohms Balanced
Output Signal to Noise
-100 dB unweighted
-104 dB A weighted
Dynamic Range
117 dB 10K Ohm load Phantom powered
112 dB 10K Ohm load Battery powered
111 dB 600 Ohm load Phantom powered
107.5 dB 600 Ohm load Battery powered
Distortion
100 Hz .0027%, 1KHz .0028%, 10KHz .0037%
Frequency Response 20Hz to 20KHz, ± 0.2 dB
Gain through Unit: 6dB (Normal input, Pad switch out)
Pad Switch: -20 dB attenuation
Speaker Input
-40 dB attenuation, equivalent to 100:1 decrease in input level
-60 dB attenuation available with Pad switch
Input Connectors
Insulated jacks (!!!Note that the Input connector switches the unit on
when a plug is inserted. Remove plug when storing to avoid battery drain!!!)
Output Connector
3 pin XLR. Wired Pin 1 Ground, Pin 2 + Hot, Pin 3 - Cold.
With Audio Ground (Pin 1) lift switch
Construction
All-steel chassis, fibreglass PCB
Battery Access
Twist connector opens chassis, snap-in battery holder inside.
No tools required