RDL RUMLD4T, RUMLD4 Data Sheet

RACK-UP® SERIES

Models RU-MLD4 & RU-MLD4T

Mic/Line Distribution Amp

ANYWHERE YOU NEED...

• Distribution Amplifier with Four Outputs

• Front Panel XLR Input / Output Jacks

• Detachable Input / Output Terminal Blocks

• Switch-selectable Mic or Line Input

• Switch-selectable Mic Gain and Phantom

• Gain-Trim on Input

• Each Output Switch-selectable Mic or Line

You Need The RU-MLD4!

The RU-MLD4 is part of the group of RACK-UP products from Radio Design Labs. RACK-UPs feature the
advanced circuitry for which RDL products are known, combined with accessible user-friendly controls and

displays. The ultra compact design permits high-density installations, with three products mounted in a

single rack unit. Optional brackets permit mounting a RACK-UP module above, below, or in front of any
flat surface!

APPLICATION: The RU-MLD4 is an audio distribution amplifier with four outputs. The input and all four

outputs may be connected through the front-panel XLR jacks or on the rear panel detachable terminal
blocks. The input accepts either a balanced microphone or line level signal. Each of the four outputs
provides either a microphone or line level signal. Both the front-panel XLR connectors and the rear-panel
terminals are active at all times. The RU-MLD4 may be rack-mounted with the XLR jacks facing forward,
or may be reverse-mounted using the RDL RU-FP1 Filler Panel/Reverse Mount Kit.

The audio input is equipped with a rear-panel switch to select between MIC and LINE level. Two
additional switches allow setting the MIC input for LO or HI gain and for enabling or disabling standard 24
Vdc phantom. The two microphone gain settings allow the connection of a wide variety of dynamic and
condenser microphones. Each output is provided with a separate rear-panel switch to set the associated
level to either MIC or LINE. Audio outputs are isolated from each other and may be wired balanced or
unbalanced.

Gain trim is provided on a front-panel control. The knurled adjustment is provided with a screwdriver slot
so the gain may be adjusted by hand or by screwdriver. An RDL Dual-led VU meter is provided above the
gain trimmer. The meter is calibrated to indicate +4 dBu for outputs set to line level.

The rear panel provides a detachable terminal block and a power input jack to connect 24 Vdc power. The
RU-MLD4 audio outputs are active balanced. Each output of the RU-MLD4T is equipped with a
studio-quality audio output transformer.

Wherever 1 in by 4 out connectorized mic and line level audio distribution with gain trim is needed to
provide superior audio clarity, user adjustments, reliability, compactness and unsurpassed versatility, the
RU-MLD4 is the ideal choice. Use the RU-MLD4 combined with other RDL RACK-UP, STICK-ON, TX™,
or FLAT-PAK™ series products as part of a complete audio/video system.

RDL • 659 N. 6th St. • Prescott, AZ., USA 86301 • [phone] • FAX [phone] • www.rdlnet.com

RACK-UP® SERIES

Model RU-MLD4
Mic/Line Distribution Amp

LEVEL IS CORRECT
WITH GREEN BRIGHT
AND RED FLASHING
OCCASIONALLY

SET INPUT GAIN
FOR CORRECT
LEVEL ON DUAL-LED
METER

CONNECT MIC OR LINE INPUT TO FRONT OR REAR

LEVEL

LEVEL

+4

+4

GAIN

GAIN

INPUT

MIC/LINE

CONNECT MIC OR LINE OUTPUTS TO FRONT OR REAR

RU-MLD4

RDL

OUTPUT 3OUTPUT 4

MLLMMLML

M = MIC
L = LINE

SET EACH OUTPUT SWITCH TO MIC OR LINE LEVEL

TURN PHANTOM ON FOR CONDENSER, OFF FOR DYNAMIC

OUTPUT 1

MIC/LINE

OUTPUT 2 OUTPUT 1

SET GAIN FOR MIC INPUT

OUTPUT 2

MIC/LINE

LIIM

N

C

HIOLFOFNO

GAIN PHM

OUTPUT 3

MIC/LINE

INPUT

Installation/Operation

EN55103-1 E1-E5; EN55103-2 E1-E4

Typical Performance reflects product at publication time
exclusive of EMC data, if any, supplied with product.
Specifications are subject to change without notice.

UNBALANCED WIRING

INPUT

OUTPUT 4

MIC/LINE

OUTPUT

SET INPUT FOR

24 VDC

MADE IN U.S.A.

CONNECT 24 VDC POWER TO
TERMINAL BLOCK OR JACK

MIC OR LINE LEVEL

TYPICAL PERFORMANCE

Input: XLR (3 pin, front panel) and detachable terminal block (rear panel)
Input level (for +4 dBu output): Switch-selectable (rear panel) MIC (LO or HI gain) or LINE

Mic: -48 dBu to -3 dBu (LO GAIN); -65 dBu to -20 dBu (HI GAIN)
Line: -15 dBu to +28 dBu

Input Impedance:
Mic:

2 kΩ balanced, switchable 24 V phantom (IEC 1938: 1996-12)

Line: > 10 kΩ balanced; may be connected unbalanced

Outputs (4): XLR (3 pin, front panel) and detachable terminal block (rear panel)
Output level: Switch-selectable (rear panel) MIC (-46 dBu) or LINE (+4 dBu)
Output Impedance: 150 Ω balanced; drives high or low impedance lines
Gain Trim: Front panel adjustable; one for each channel
Mic

LO GAIN: Off to 52 dB gain

Mic HI GAIN: Off to 69 dB gain

Line: Off to 20 dB gain

Frequency Response:
Mic: 80 Hz to 50 kHz (+/- 0.75 dB); < 10 dB @ 20 Hz (integral high-pass filter)
Line: 15 Hz to 50 kHz (+/- 0.1 dB)

THD+N:
Mic: < 0.1% (80 Hz to 20 kHz)
Line: < 0.005%
CMRR: > 60 dB (Mic); > 50 dB (Line)
Residual Noise (below +4 dBu LINE output or -45 dBu MIC output):
Mic 40dB Gain, LO GAIN: -79 dB (20 Hz to 20 kHz)
Mic 50dB Gain, HI GAIN: -79 dB (20 Hz to 20 kHz)
Mic 60dB Gain, HI GAIN: -70 dB (20 Hz to 20 kHz)
Line: -85 dB (20 Hz to 20 kHz)
Headroom (above +4 dBu LINE output): > 20 dB

Power Requirement: 24 to 33Vdc @ 90 mA, Ground-referenced

891-3225

Radio Design Labs Technical Support Centers

U.S.A. [phone], [phone]; Fax: [phone]

Europe [NH Amsterdam] (++31) 20-6238 983; Fax: (++31) 20-6225-287