Radio Design Labs ST-VCA3
Voltage-Controlled Amplifier

OUR PART #  STVCA3


Radio Design Labs' ST-VCA3 is used in applications requiring smooth audio level control from a remote control panel, potentiometer or dc voltage (0 to 10 V). Installation in series with the audio input of a power amplifier allows remote control of that amplifier’s level. For installations where it is preferred to keep the audio localized in the rack, audio controls are extended outside the rack from the ST-VCA3.

Many installations benefit from avoiding long-term potentiometer wear from audio running through the potentiometer. An ST-VCA3 with external dc control provides virtual immunity from scratchy audio. Audio/video system control units often provide 0 to 10 Vdc control outputs that can directly control audio levels using an ST-VCA3.

The ST-VCA3 is primarily intended for line-level attenuation; a high quality utility microphone preamplifier is included in the module. If remote control of a microphone preamplifier is desired, such as a wall mounted level control for a microphone jack, the ST-VCA3 may serve as a remote controlled microphone preamplifier.

NOTE: Radio Design Labs' PS-24AS power supply is NOT included but is required in order to power this product.  Please see the "Accessories" tab or click here for more information on the PS-24AS power supply.

Features:

  • Audio Level Remote Control
  • Audio Level Control from a DC Voltage
  • VCA with Microphone or Line Level Input
  • VCA with Line-Level Output
  • VCA with LED Metering of Operating Level
  • Two Wire with Shield or Three Wire Control

Specifications:

  • Inputs (2):
    - Mic: 200 Ohms balanced; 5 k Ohms unbalanced
    - Line: 30 k Ohms bal. bridging or unbalanced
  • Input Levels (for +4 dBu output):
    - Mic: –44 dBu to –60 dBu (150 Ohms source)
    - Line: -18 dBu (-20 dBV) to +4 dBu
  • Output Signal (normal rated): +4 dBu, 150 Ohms balanced
  • Headroom: 18 dB
  • THD+N:
    - Mic: < 0.05%
    - Line: <0.025% (unity gain)
    0.025% typical at 15 dB attenuation
  • Frequency Response:
    - Mic: 30 Hz to 20 kHz (±1 dB)
    - Line: 10 Hz to 20 kHz (±0.1 dB)
  • Noise:
    - Mic: < -71 dB below +4 dBu output (150 Ohms source; 50 dB gain)
    - Line: <-78 dB below +4 dBu output (maximum gain)
  • CMRR:
    - Mic: > 60 dB
    - Line: > 60 dB, (50 Hz to 120 Hz)
  • Control Input: 0 to 10 Vdc or 0 to 10 k Ohms Linear
  • Attenuation Range: 0 to 90 dB (>90 dB at 0 Vdc control)
  • Power Requirement: GROUND-REFERENCED, 24 to 33 Vdc @ 50 mA
  • Dimensions: 0.7" H x 3" W x 1.6" D (1.7 x 7.6 x 3.9 cm)
Rackmount System for 12 Stick-On Units
Radio Design Labs STR-19A Rackmount System for 12 Stick-On Units
Radio Design Labs' STR-19A Racking System holds up to 12 STICK-ONs in a 19" rack and only occupies two rack spaces.
Stick-On Mounting Rack for 10 Units
Radio Design Labs SR-10 Stick-On Mounting Rack for 10 Units
Radio Design Labs' STR-10 Racking System holds up to 10 STICK-ON units.  It holds STICK-ONs at an angle allowing for control adjustment from either the edge of a STICK-ON, or the top (depending on where the adjustment is located on ...
24 VDC 500mA Switching Power Supply, North American Model
Radio Design Labs PS-24AS 24 VDC 500mA Switching Power Supply, North American Model
Radio Design Labs' PS-24AS is a 24 VDC/500 mA switching power supply with a North American AC plug. Compatible with various RDL products.Radio Design Labs PS-24AS Specifications: Input: 100 to 240 VAC Output: 24 Vdc, 500 mA (UL, ...
Din Rail Adaptor for STICK-ON
Radio Design Labs DRA-35S Din Rail Adaptor for STICK-ON
The DRA-35S is a 35 mm DIN rail mounting bracket that provides positive mounting for any RDL STICK-ON® module. The oblique mounting angle of the DRA-35S allows an installer to mount several STICK-ON modules to a single DIN rail. Access to ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Kit for STICK-ON, TX, or Rack-Up module
Radio Design Labs MB1-RDL Mounting Kit for STICK-ON, TX, or Rack-Up module
Two mounting brackets mounts a STICK-ON, TX, or Rack-Up module to a flat surface.
Rackmount Kit for 10 Stick-On Units
Radio Design Labs STR-19B Rackmount Kit for 10 Stick-On Units
Radio Design Labs' STR-19B Racking System holds up to 10 STICK-ON unitss in a 19 inch rack and only occupies two rack spaces. The STR-19B holds STICK-ONs at an angle allowing for control adjustment from either the edge of a STICK-ON, or ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Frame for Stick/TX
Radio Design Labs SR-4 Mounting Frame for Stick/TX
Radio Design Labs' SR-4 is a universal module chassis that can mount to a backboard, wall or nearly any other support. It provides mounting for 4 STICK-ON power amplifiers or 7 standard STICK-ON modules. TX ™ modules may also be mounted. ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
STICK-ON Series 19"W Mounting Rack for up to12 Modules
Radio Design Labs SR-12A STICK-ON Series 19"W Mounting Rack for up to12 Modules
Radio Design Labs' SR-12A chassis can be mounted in a rack or on a backboard to provide mounting of 12 STICK-ONs.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Strip for STICK-ON Units
Radio Design Labs Smk 12 Mounting Strip for STICK-ON Units
The SMK-12 allows removable surface (up to 6 units) or edge (typically 12, max. 16) mounting of STICK-ON units. They can be fastened to its surface using screws or adhesive foam pads.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Bracket for STICK-ON Modules
Radio Design Labs ST-RRB1 Mounting Bracket for STICK-ON Modules
Radio Design Labs' ST-RRB1 mounting kit contains a bracket to attach a STICK-ON module to a rear rack rail or to any flat surface. The module slides into the holder and snaps into position. The module may easily be removed.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Detachable Terminal Block
Radio Design Labs Dtb Rdl Detachable Terminal Block
Use DTB's to quickly detach and reattach wiring harness to STICK-ON units.

Usually ships in 7-14 business days.
Need it sooner? Call us!

Click to download

Radio Design Labs ST-VCA3
Voltage-Controlled Amplifier

OUR PART #  STVCA3

Product Information:

Radio Design Labs' ST-VCA3 is used in applications requiring smooth audio level control from a remote control panel, potentiometer or dc voltage (0 to 10 V). Installation in series with the audio input of a power amplifier allows remote control of that amplifier’s level. For installations where it is preferred to keep the audio localized in the rack, audio controls are extended outside the rack from the ST-VCA3.

Many installations benefit from avoiding long-term potentiometer wear from audio running through the potentiometer. An ST-VCA3 with external dc control provides virtual immunity from scratchy audio. Audio/video system control units often provide 0 to 10 Vdc control outputs that can directly control audio levels using an ST-VCA3.

The ST-VCA3 is primarily intended for line-level attenuation; a high quality utility microphone preamplifier is included in the module. If remote control of a microphone preamplifier is desired, such as a wall mounted level control for a microphone jack, the ST-VCA3 may serve as a remote controlled microphone preamplifier.

NOTE: Radio Design Labs' PS-24AS power supply is NOT included but is required in order to power this product.  Please see the "Accessories" tab or click here for more information on the PS-24AS power supply.

Features:

  • Audio Level Remote Control
  • Audio Level Control from a DC Voltage
  • VCA with Microphone or Line Level Input
  • VCA with Line-Level Output
  • VCA with LED Metering of Operating Level
  • Two Wire with Shield or Three Wire Control

Specifications:

  • Inputs (2):
    - Mic: 200 Ohms balanced; 5 k Ohms unbalanced
    - Line: 30 k Ohms bal. bridging or unbalanced
  • Input Levels (for +4 dBu output):
    - Mic: –44 dBu to –60 dBu (150 Ohms source)
    - Line: -18 dBu (-20 dBV) to +4 dBu
  • Output Signal (normal rated): +4 dBu, 150 Ohms balanced
  • Headroom: 18 dB
  • THD+N:
    - Mic: < 0.05%
    - Line: <0.025% (unity gain)
    0.025% typical at 15 dB attenuation
  • Frequency Response:
    - Mic: 30 Hz to 20 kHz (±1 dB)
    - Line: 10 Hz to 20 kHz (±0.1 dB)
  • Noise:
    - Mic: < -71 dB below +4 dBu output (150 Ohms source; 50 dB gain)
    - Line: <-78 dB below +4 dBu output (maximum gain)
  • CMRR:
    - Mic: > 60 dB
    - Line: > 60 dB, (50 Hz to 120 Hz)
  • Control Input: 0 to 10 Vdc or 0 to 10 k Ohms Linear
  • Attenuation Range: 0 to 90 dB (>90 dB at 0 Vdc control)
  • Power Requirement: GROUND-REFERENCED, 24 to 33 Vdc @ 50 mA
  • Dimensions: 0.7" H x 3" W x 1.6" D (1.7 x 7.6 x 3.9 cm)
Rackmount System for 12 Stick-On Units
Radio Design Labs STR-19A Rackmount System for 12 Stick-On Units
Radio Design Labs' STR-19A Racking System holds up to 12 STICK-ONs in a 19" rack and only occupies two rack spaces.
Stick-On Mounting Rack for 10 Units
Radio Design Labs SR-10 Stick-On Mounting Rack for 10 Units
Radio Design Labs' STR-10 Racking System holds up to 10 STICK-ON units.  It holds STICK-ONs at an angle allowing for control adjustment from either the edge of a STICK-ON, or the top (depending on where the adjustment is located on ...
24 VDC 500mA Switching Power Supply, North American Model
Radio Design Labs PS-24AS 24 VDC 500mA Switching Power Supply, North American Model
Radio Design Labs' PS-24AS is a 24 VDC/500 mA switching power supply with a North American AC plug. Compatible with various RDL products.Radio Design Labs PS-24AS Specifications: Input: 100 to 240 VAC Output: 24 Vdc, 500 mA (UL, ...
Din Rail Adaptor for STICK-ON
Radio Design Labs DRA-35S Din Rail Adaptor for STICK-ON
The DRA-35S is a 35 mm DIN rail mounting bracket that provides positive mounting for any RDL STICK-ON® module. The oblique mounting angle of the DRA-35S allows an installer to mount several STICK-ON modules to a single DIN rail. Access to ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Kit for STICK-ON, TX, or Rack-Up module
Radio Design Labs MB1-RDL Mounting Kit for STICK-ON, TX, or Rack-Up module
Two mounting brackets mounts a STICK-ON, TX, or Rack-Up module to a flat surface.
Rackmount Kit for 10 Stick-On Units
Radio Design Labs STR-19B Rackmount Kit for 10 Stick-On Units
Radio Design Labs' STR-19B Racking System holds up to 10 STICK-ON unitss in a 19 inch rack and only occupies two rack spaces. The STR-19B holds STICK-ONs at an angle allowing for control adjustment from either the edge of a STICK-ON, or ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Frame for Stick/TX
Radio Design Labs SR-4 Mounting Frame for Stick/TX
Radio Design Labs' SR-4 is a universal module chassis that can mount to a backboard, wall or nearly any other support. It provides mounting for 4 STICK-ON power amplifiers or 7 standard STICK-ON modules. TX ™ modules may also be mounted. ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
STICK-ON Series 19"W Mounting Rack for up to12 Modules
Radio Design Labs SR-12A STICK-ON Series 19"W Mounting Rack for up to12 Modules
Radio Design Labs' SR-12A chassis can be mounted in a rack or on a backboard to provide mounting of 12 STICK-ONs.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Strip for STICK-ON Units
Radio Design Labs Smk 12 Mounting Strip for STICK-ON Units
The SMK-12 allows removable surface (up to 6 units) or edge (typically 12, max. 16) mounting of STICK-ON units. They can be fastened to its surface using screws or adhesive foam pads.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Bracket for STICK-ON Modules
Radio Design Labs ST-RRB1 Mounting Bracket for STICK-ON Modules
Radio Design Labs' ST-RRB1 mounting kit contains a bracket to attach a STICK-ON module to a rear rack rail or to any flat surface. The module slides into the holder and snaps into position. The module may easily be removed.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Detachable Terminal Block
Radio Design Labs Dtb Rdl Detachable Terminal Block
Use DTB's to quickly detach and reattach wiring harness to STICK-ON units.

Usually ships in 7-14 business days.
Need it sooner? Call us!

Click to download

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