STICK-ON® SERIES
Model STM-2X
Switchable Low-Noise
Microphone Preamplifier
ANYWHERE YOU NEED...
• Quiet Switching of Condenser Mic
• Remote Microphone Soft-Switching
• Switched Mic-Level Source with Mic or
Line-Level Output
• Remote Toggle or Push-to-Talk
• Adjustable Preset Gain on Microphone
Source
You Need The STM-2X!
The STM-2X is part of the group of versatile STICK-ON products from Radio Design Labs, featuring the
advanced circuitry for which RDL products are known. The durable adhesives provided with the STM-2X
permit permanent or detachable mounting. Numerous mounting accessories, brackets and rack-mount
chassis are optionally available to facilitate any system design.
APPLICATION: The STM-2X is the ideal choice in many installations where a microphone preamplifier is
required, and is the ideal choice where either a toggle-type switch or push-to-talk switch is to be provided
for microphone control, particularly if condenser microphones are used.
The STM-2X features a balanced mic-level input, and both a line-level and mic-level output. The input and
each output may be wired balanced or unbalanced. A 25-turn trimming potentiometer is provided for
precise level adjustment whether the module is being used as a mic-level switch, or as a switched
mic-to-line preamplifier. A phantom voltage input is provided for use with condenser mics. The 24 Vdc
power source is typically used as the phantom supply, requiring no other external phantom supply. These
features permit the STM-2X to be used as a manually switched mic preamp, or as a mic-level remote
switch for dynamic or condenser microphones. The mic-level output from the STM-2X may be safely
connected to other equipment mic inputs which produce phantom voltage.
It is frequently necessary to provide user accessible switching for condenser microphones. This may
include a simple mic on/off switch, push-to-talk or a cough button switch. Conventional methods of either
shorting or opening the microphone line results in loud audible pops due to the phantom voltage on the
mic line. For these applications, the STM-2X provides quiet, solid-state soft switching with no disruption to
the phantom voltage. The output of the STM-2X is turned on by grounding the control terminal, either by a
switch or by any of the SLAVE terminals from other RDL products.
Wherever mic signals need to be switched, or switched and preamplified, the STM-2X is the ideal choice.
Use the STM-2X individually, or combine it 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 •• (805) 684-5415 •• FAX (805) 684-9316 •• http://www.rdlnet.com
STICK-ON® SERIES
Model STM-2X
Switchable Low-Noise Mic Preamp
SWITCHABLE LOW-NOISE
G
INPUT PHNTM
A
I
N
SIGNAL
FROM
UNBALANCED
MIC-LEVEL
SOURCE
G
INPUT PHNTM
A
I
N
MICROPHONE PREAMPLIFIER
C
T
R
L
UNBALANCED
LINE-LEVEL
EQUIPMENT
SWITCHABLE LOW-NOISE
MICROPHONE PREAMPLIFIER
C
T
R
L
LINE
SIGNAL
FEEDING
OUTPUTS
MIC
FEEDING
UNBALANCED
MIC-LEVEL
EQUIPMENT EQUIPMENT
PWR
SIGNAL
P
O
W
E
R
G
INPUT PHNT
A
I
N
SPKR USED
AS MIC
AUDIO
WIRING
EACH INPUT/OUTPUT MAY BE WIRED BALANCED OR UNBALANCED
POWER/
CONTROL
P
O
W
E
R
WIRING
LINE
OUTPUTS
PWR
MIC
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.
SWITCHABLE LOW-NOISE
G
A
I
N
SIGNAL
FROM
BALANCED
MIC-LEVEL
SOURCE
G
A
I
N
MICROPHONE PREAMPLIFIER
INPUT PHNTM
C
T
R
L
LINE-LEVEL
SWITCHABLE LOW-NOISE
MICROPHONE PREAMPLIFIER
INPUT PHNTM
C
T
R
L
OUTPUTS
LINE
SIGNAL
FEEDING
BALANCED
OUTPUTS
LINE
MIC
FEEDING
BALANCED
MIC-LEVEL
EQUIPMENT
MIC
PWR
SIGNAL
PWR
P
O
W
E
R
P
O
W
E
R
RDL PS-24
TYPE
SUPPLY
PHANTOM
DC POWER
SOURCE
OR
OPTIONAL JUMPER
TO PROVIDE PHANTOM
VOLTAGE TO CONDENSER
MIC WHICH CAN USE UP
TO 32 VOLTS PHANTOM
24 Vdc
POWER
SOURCE
TYPICAL PERFORMANCE
Input: Mic level, dynamic or condenser
Input Source Impedance: 150 to 600 Ω balanced; 5 kΩ unbal
Outputs (2):
Line Level (1): Balanced (+4 dBu nominal)
Mic Level (1): Balanced (-45 dBu)
Headroom: >18 dB
Gain Range:
Line-Level Output: Off to +65 dB
Mic-Level Output: Off to +15 dB
Frequency Response: 50 Hz to 25 kHz (+/-1 dB)
THD+N: <0.05%
Radio Design Labs Technical Support Centers
U.S.A. (800) 933-1780, (928) 778-3554; Fax: (928) 778-3506
891-0100I
Europe [NH Amsterdam] (++31) 20-6238 983; Fax: (++31) 20-6225-287
OPEN COLLECTOR
ACTUATION
OR
RDL MODULE
OR
SLAVE TERMINAL
SWITCH TYPE
NORM OPEN
NORM CLOSED PUSH TO MUTE
PUSH TO TALK (SHOWN)
Residual Noise (ON): <-70 dB (referred to +4 dBu)
(150 Ω source @ 50 dB gain)
<-75 dB (referred to +4 dBu)
(600 Ω source @ 60 dB gain)
OFF Attenuation:
>85 dB @ 1 kHz (>70 dB 50 Hz to 10 kHz)
Switching Control Input: Connect to ground to activate signal;
15 mA maximum current required
Switching Time: <5 ms on transition;
125 ms initial (30 dB) OFF transition
CMRR: >50 dB (60 or 120 Hz)
Power Requirement:
24 to 33 Vdc @ 30 mA, Ground-referenced
(12 Vdc with >12 dB headroom and
5 ms decrease in ON transition time)
Loading...