ST-UMX3 - Hand blender RDL - Free user manual and instructions

Product Type	Universal Audio Mixer
Number of Inputs	3 (switch selectable mic or line)
Input Impedance (Mic)	600 Ω balanced
Input Impedance (Line)	50 kΩ balanced
Maximum Input Signal (Mic)	-18 dBu
Maximum Input Signal (Line)	+25 dBu
Gain Adjustment (Mic)	0 to 60 dB, single-turn potentiometer
Gain Adjustment (Line)	0 to 21 dB, single-turn potentiometer
Output Type	Switch selectable mic or line level, balanced or unbalanced
Output Impedance	150 Ω balanced; 75 Ω unbalanced
Output Level (Line)	+4 dBu nominal
Output Level (Mic)	50 dB below line level
Total Harmonic Distortion + Noise	<0.006%
Intermodulation Distortion (Mic @ 50 dB gain)	<0.04%
Intermodulation Distortion (Line)	<0.008%
Frequency Response (Mic)	50 Hz – 100 kHz (±1 dB)
Frequency Response (Line)	10 Hz – 100 kHz (±0.05 dB)
Noise (Mic @ 50 dB gain)	< -70 dB
Noise (Line @ unity gain)	< -82 dB
Common Mode Rejection Ratio (Mic)	> 60 dB
Common Mode Rejection Ratio (Line)	> 50 dB (50 – 120 Hz)
Headroom	18 dB
Power Requirement	24 Vdc @ 55 mA, ground-referenced
Mounting	Adhesive backing (STICK-ON®) or optional rack accessories
Ambient Operating Temperature	0°C to 55°C
Phantom Power Warning	Mic inputs not protected against phantom voltage; use ST-MPA24 or ST-MPA48 adapter

Frequently Asked Questions - ST-UMX3 RDL

How do I connect a dynamic microphone to the ST-UMX3?

Connect the dynamic mic to one of the three input channels. Ensure the corresponding MIC/LINE switch is set to MIC. No phantom power is needed for dynamic mics.

Can I use condenser microphones with this mixer?

Yes, but the ST-UMX3 does not provide phantom power. You must use an external phantom power supply like the RDL ST-MPA24 or ST-MPA48 in line with the mic signal.

What power supply is required?

The ST-UMX3 requires a 24 Vdc ground-referenced power supply, consuming 55 mA. Many RDL power supplies are compatible.

How do I set the input gain?

Each input has a single-turn gain adjustment potentiometer. While monitoring the output VU meter, adjust the gain until the green LED reaches full intensity at +4 dBu, avoiding red LED flashing.

What is the difference between the mic and line output settings?

The OUTPUT MIC/LINE switch selects the output level. LINE provides +4 dBu nominal, while MIC is padded 50 dB lower, suitable for feeding mic-level inputs.

Can I mount the ST-UMX3 permanently?

Yes, the adhesive backing allows permanent or removable mounting on clean, flat surfaces. Alternatively, use RDL's rack accessories for standard rack installation.

What is the output impedance?

The output is 150 Ω balanced or 75 Ω unbalanced, capable of driving high or low impedance loads.

Is the mixer suitable for line-level signals only?

No, each input is switchable between MIC and LINE. You can mix both mic and line sources on different channels.

How do I interpret the dual LED VU meter?

The green LED intensity indicates level from -11 dBu (minimum) to +4 dBu (full). The red LED flashes when the signal exceeds 0 dBu, indicating potential clipping.

What are the typical applications for this mixer?

It is ideal for combining multiple mic or line signals into one output in small audio systems, conference rooms, broadcast, or as a submixer in larger installations.

USER MANUAL ST-UMX3 RDL

STICK-ON® SERIES Model ST-UMX3 Universal Audio Mixer

• Audio Mixing with Up To Three Inputs
- Switch Selectable Mic or Line Inputs
- Switch Selectable Mic or Line Output
- Add Additional Microphone or Line Level Inputs to an Existing Mixer
- Combine Signals of Different Level, Impedance, or Bal. / Unbal. Configuration

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. STICK-ONs are designed, built and rated for continuous duty in professional A/V systems.

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 individually, or combine it with other RDL products as part of a complete audio/video system.

STICK-ON® SERIES

Model ST-UMX3

Universal Audio Mixer

Installation/Operation

Declaration of Conformity available from rdlnet.com. Sole EMC specifications provided on product package. Specifications are subject to change without notice.

AUDIO WIRING

CONDENSER MIC CONNECTION
(USING ST-MPA24 OR ST-MPA48 MODULE FOR PHANTOM VOLTAGE)

*DYNAMIC MIC CONNECTIONS (NO PHANTOM VOLTAGE)

SELECTABLE MIC OR LINE LEVEL

EACH INPUT AND THE OUTPUT MAY BE SET TO MIC OR LINE LEVEL

LINE LEVEL

MIC LEVEL

ADJUST LEVELS

SUPPLY WIRING

TYPICAL PERFORMANCE

Inputs (3):

Mic: 600 Ω balanced; Line: 50 kΩ balanced

NOTE: MIC INPUTS ON ST-UMX3 ARE NOT PROTECTED

AGAINST PHANTOM VOLTAGE. USE THE ST MPA48 or

ST-MPA24 Mic Phantom Adapter.

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

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)

Ambient Operating Environment: 0^ C to 55^ C

Power Req.: GROUND-REFERENCED, 24 Vdc @ 55 mA