RDL STUMX3 Data Sheet

STICK-ON® SERIES

Model ST-UMX3
Universal Audio Mixer

ANYWHERE YOU NEED...

•

Audio Mixing with Up To Three Inputs

•

Switch Selectable Mic or Line Inputs

•

Switch Selectable Mic or Line Output

• To Add Additional Microphone or Line
Level Inputs to an Existing Mixer

•

To Combine Signals of Different Level,
Impedance, or Bal./Unbal. Configuration

You Need The ST-UMX3!

The ST-UMX3 is part of a group of products in the STICK-ON series from Radio Design Labs. The
durable bottom adhesive permits quick, permanent or removable mounting nearly anywhere or it may be
used with RDL’s racking accessories. The ST-UMX3 gives you the advantage of a high performance
audio mixer with a big PLUS, you can put it where you need it.

APPLICATION: The ST-UMX3 is a three-channel audio mixer for combining mic-level or line-level
signals to a single output. A MIC/LINE switch is provided for each input. A separate MIC/LINE switch
selects the output level. Each input features a separate preamplifier circuit, which isolates it from the
other inputs. An audio-taper, single-turn gain adjustment is provided for each of the three input preamps.
Signals from the three preamps are actively summed and fed to the output line-level driver amplifier. The
output amplifier includes an RDL dual-LED VU meter.

The mic-level input circuits accept either balanced low-impedance mics or high-impedance unbalanced
mics. The line-level input circuits bridge any line-level audio source. The output is switch-selectable for
mic-level or line-level, and is capable of driving either high or low impedance, balanced or unbalanced
loads.

Each input level is set while observing the LED output level meter. The dual LED output meter follows
standard VU ballistics. The intensity of the green LED progresses from minimum at -11 dBu to full
intensity at +4 dBu. Flashing of the red LED is equivalent to a VU meter needle swinging above the
0 level. If the output is switched to MIC level, the meter continues to indicate correct operating level. The
output MIC level is padded 50dB below the normal LINE output level.

The ST-UMX3 is powered from ground-referenced 24 Vdc, permitting the module to share a common
power source with most RDL modules.

The flexibility of switching each input and the output between MIC or LINE allows installers to address a
wide variety of mixing solutions with only one product type. Wherever a flexible mic and line level mixing
amplifier is needed, the ST-UMX3 is the ideal choice. Use the ST-UMX3 combined with other RDL
RACK-UP®, STICK-ON, TX™, or FLAT-PAK™ series products as part of a complete audio/video system.

RDL • P.O. Box 1286 • Carpinteria, CA., USA 93014 • [phone] • FAX [phone] • http://www.rdlnet.com

Europe [NH Amsterdam] (++31) 20

-

6238 983; Fax: (++

31) 20

-

6225-287

STICK-ON® SERIES

Model ST-UMX3
Universal Audio Mixer

G
A

I

N

SIGNAL

FROM

BALANCED

LINE-LEVEL

OR *MIC-LEVEL

SOURCE

(SELECTABLE)

UNIVERSAL AUDIO MIXER

INPUTS

1

LM

M L2M L3M L

OTHER
BALANCED
OR UNBAL

MIC OR LINE

INPUTS

M

OUTPUT M

I

C

PWR

SIGNAL

FEEDING

BALANCED

LINE-LEVEL

OR MIC-LEVEL

SOURCE

(SELECTABLE)

L

L

I

N

L

E

E
V
E
L

BALANCED
OR UNBAL

MIC OR LINE

SIGNAL

FROM

UNBALANCED

LINE-LEVEL

OR *MIC-LEVEL

SOURCE

(SELECTABLE)

AUDIO WIRING

OTHER

INPUTS

SIGNAL

FEEDING

UNBALANCED

LINE-LEVEL

OR MIC-LEVEL

SOURCE

(SELECTABLE)

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.

DUAL MIC PHANT

ADJUST
LEVELS
USING
METER

NORMAL

HIGH

MIC

SIGNAL

FROM
BALANCED
MIC-LEVEL

SOURCE

PHANTOM VOLTAGE ADJUS

MIC 1

OUT MIC

MIC 2

OUT

G
A

I

N

21

M L

*DYNAMIC MIC CONNECTIONS

(NO PHANTOM VOLTAGE)

SELECTABLE MIC OR LINE LEVEL

EACH INPUT AND THE OUTPUT MAY

BE SET TO MIC OR LINE LEVEL

M

L

LM

I

I
NC
E

LINE LEVEL

MIC LEVEL

L

MML

I

I

C

N
E

SUPPLY

WIRING

ADJUST
LEVELS

TYPICAL PERFORMANCE

Inputs (3): Mic: 600 Ω balanced; Line: 50 kΩ balanced

Max Input Signal: Mic: -18 dBu; Line: +25 dBu
Gain (each input): Mic: Adjustable from OFF to 60 dB
Line: Adjustable from OFF to 21 dB
Output: 150 Ω balanced; 75 Ω unbalanced
Output Signal: +4 dBu nominal, mic level 50 dB below line level

891-1105

NOTE: MIC INPUTS ON ST-UMX3 ARE NOT
PROTECTED AGAINST PHANTOM VOLTAGE.
USE THE ST MPA2 Mic Phantom Adapter.

Radio Design Labs Technical Support Centers

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

CONDENSER MIC CONNECTION

(USING ST-MPA2 MODULE FOR PHANTOM VOLTAGE)

THIS

TERMINAL

IS COMMON

GROUND

24 VDC

POWER

SOURCE

THD+N: < 0.006%
IMD: Mic (@ 50dB gain): < 0.04%: Line: < 0.008%
Freq. Response: Mic: 50 Hz to 100 kHz (+/- 1 dB)
Line: 10 Hz to 100 kHz (+/- 0.05 dB)
Noise (each input): Mic: < -70 dB (50 dB gain)
Line: < -82 dB (unity gain)
Headroom: 18 dB
CMRR: Mic: > 60 dB; Line: > 50 dB (50 to 120 Hz)
Power Req.: 24 to 33 Vdc @ 55 mA, Ground-referenced