Part Number: VCA3-103
Function: Voltage Controlled Amplifier
1. Audio Level Control from a DC Voltage
2. Audio Level Remote Control
3. Two Wire with Shield or Three Wire Control
4. VCA with Microphone or Line Level Input
5. VCA with Line Level Output
6. VCA with LED Metering of Operating Level
The 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.
The ST-VCA3 is a high performance voltage controlled amplifier with two inputs and one
output. The line input is designed to accept an input signal with operating levels between -20 dBV and +4 dBu. The microphone input accepts low or high impedance microphones with output levels from –60 to –44 dBu. Only one of the inputs may be used at a time. A multi-turn trimmer is provided for setting the correct input gain according to the dual-LED VU meter located directly in front of the gain control. The intended output level is +4 dBu for 10 Vdc at the CTRLinput terminal. The green metering LED begins illuminating at 15 dB below +4 dBu. The green LED progresses to full intensity at +4 dBu. The adjacent red LED illuminates at +4 dBu.
VCA3 Datasheet / ST-VCA3 Datasheet