RDL RUMX4L Quick Start Guide

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Model RU-MX4L
Pro Audio Line Level Mixer

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SERIES

ANYWHERE YOU NEED...

• Four Channel Line-Level Audio Mixer

•

XLR Balanced, Phono Jack Unbalanced Inputs

• Mic or Line XLR Output, Switchable

• Unbalanced Line Output and Direct Input

• Studio Quality, Low-Noise Performance

• Expansion Bussing Capability

• Additional Line Inputs Bussed to an RU-MX4

• Output Isolation Transformer (RU-MX4LT)

You Need The RU-MX4L(T)!

The RU-MX4L is part of the group of RDL RACK-UP products. The compact design permits high-density installations, with three
products mounted in a single rack unit. The RU-MX4L may be used alone, or mounted using a wide variety of RACK-UP series
options.

APPLICATION: The RU-MX4L is the ideal choice in many applications where a combination of balanced line and/or unbalanced

line-level signals need to be mixed. All balanced connections are made through XLR connectors. Unbalanced signals are coupled
through phono jacks. The RU-MX4L may be used as a standalone mixer, or may be connected to an RDL RU-MX4 Mic/Line Mixer
to provide four additional line level inputs.

Each of the four RU-MX4L inputs can accept either a balanced XLR line or an unbalanced line-level phono jack input.

A separate unbalanced DIRECT input allows an external audio source to be summed directly into the mix amplifier, bypassing the
front-panel input level controls. The unbalanced phono jack LINE OUTPUT from one RU-MX4L may connect to the unbalanced
input of other equipment, or may be connected to the DIRECT input of another RU-MX4L or an RU-MX4 to expand mixing

capabilities. Up to 3 RU-MX4 type mixers may be rack mounted in a single rack unit using an RDL RU-RA3HD rack adapter. A
power interconnect cable is supplied with each RU-MX4L allowing the rack mounted mixers to run from a single 24 Vdc power
supply.

The RU-MX4L provides one balanced output, switchable for mic or line level. The balanced XLR output and the unbalanced phono
jack output may be used at the same time.

Audio levels are adjustable on the front panel. A convenient label area is provided below each fader knob. A label tab included with
the mixer may be professionally labeled using a commercial lettering machine, or the user may write on the front of the tab. The tab
locks into a protected pocket inside the RU-MX4L front panel for a professionally labeled appearance.

Each input channel is equipped with a front-panel dual-LED VU meter that follows standard VU ballistics. A green LED illuminates
at 15 dB below the optimum input gain, becoming progressively brighter with increasing audio level. The adjacent red LED
illuminates when the input gain exceeds the correct operating level. Maximum headroom and signal-to-noise are assured when
these individual input meters are used to correctly adjust each input gain.

The final mix is displayed on an LED string VU meter featuring a visually comfortable arc motion. An optional security cover (RU­MX4SC) is available to prevent user access to the rear panel switches. The RU-MX4L is electronically balanced. A factory
installed output isolation transformer is available by ordering the RU-MX4LT.

Wherever a line-level mixer is needed to provide superior audio clarity, user adjustments, reliability, compactness and unsurpassed
versatility, the RU-MX4L is the ideal choice. Use the RU-RA3HD rack-mount adapter to mount multiple RU-MX4 type mixers, or to
combine related products (such as audio or video distribution, or audio metering) into a single rack unit!

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

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SERIES

Model RU-MX4L
Professional Audio Line Mixer

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.

TYPICAL PERFORMANCE

Balanced Line Inputs(4): 20 kΩ balanced bridging
Balanced Line Input Level: -13 to +22 dBu for +4 dBu output
Unbalanced Line Inputs (4): 2 kΩ unbalanced
Unbalanced Line Input Level: -25 dBV to +20 dBV for +4 dBu output; -10 dBV nominal
Gain Adjustments (5): Balanced Line: Off to 17 dB gain
Unbalanced Line: Off to 27 dB gain
Output Attenuator: 0 dB to infinity
Frequency Response: 20 Hz to 30 kHz (+/- 0.25 dB)
THD+N: < 0.01%
Residual Noise (below +4dBu output): 4 line level sources (unity gain): < -82 dB (wideband)

Outputs (2): +4 dBu 150 Ω balanced (switchable MIC or LINE); -10 dBV unbalanced
Indicators (17): Dual-LED VU meter for each input; POWER LED;

8-segment bar mode string LED audio mix level meter, 0 dB = +4 dBu
VU ballistic: -20 dB, -10 dB, -6 dB, -2 dB, 0 dB, +3 dB; Peak reading: +8 dB,+12 dB
Power Requirement: 24 Vdc @ 150 mA, Ground-referenced

Overall Dimensions: Height: 1.7 in. 4.3 cm
Length: 5.8 in. 15.0 cm
Depth: 4.8 in. 12.2 cm

Radio Design Labs Technical Support Centers

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

891-3195A

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