The AVC 2D controls the sound level of a system to a set maximum, if the incoming signal is below the set threshold the AVC 2D has no effect. If the average programme level exceeds the set threshold the AVC 2D will reduce its gain to hold the output level at the set maximum. The gain is reduced slowly so as not to affect the dynamics of the music and is almost undetectable in use.
Once the set threshold is reached any increases the input level (volume) is offset by reducing the gain, so that the system will barely change in perceived level. A 2 X 20 segment multi-function liquid crystal display (LCD) shows the mode in use and the attenuation level in both channels, there is also a clip indicator LED. There is provision to connect remote warning and clip LED indicators.
The AVC 2D is installed in the signal chain before the amplifiers, in modes 1 and 2 the amplifiers must either be locked away or set to maximum gain (so the amplifiers cannot be turned up after the maximum level is set). In mode 3 a microphone is used to monitor the actual sound level so turning up amplifiers will not increase the sound level.
Utilising digital control circuits and a very pure analogue signal chain the audio quality of the sound system is maintained while achieving the required degree of sound level control.
With 3 operating modes currently featured, it is envisaged that upgrades will be available that will allow the AVC 2D to fulfil further functions. e.g. The ability to intelligently adjust the level of a sound system (paging etc.) depending on the surrounding ambient noise level.
Key Features of Formula Sound Digital Automatic Volume Control unit with LCD display
- 3 modes: Stereo, mono and microphone signal monitoring.
- An LCD on the front panel displays all the information regarding set-up and attenuation figures.
- Or added flexibility, the attack and decay times can be adjusted as well as trigger levels.
- Discreet 1db steps of attenuation mean that the fading is not noticeable.
Specifications
- Frequency response: 20Hz - 20kHz, +/- 0.5dB
- Distortion(THD and noise) freq 1kHz: O/P@ any level 0 to +22dBu, Attenuation @ any level: 0 to -90dB 0.01% (typically 0.005%)
- Noise measured 20Hz-20kHz: Equiv. input noise,
- INPUTS: Electronically balanced, connect pins 1 & 3 to screen pin 2 hot for unbalanced use
- XLR Connectors: Pin 1 screen Pin 3 -Ve Non Phase Pin 2 +Ve Phase
- Input impedance: Balanced 20K ohms, Unbalanced 10K ohms
- Maximum input level: +22dBu
- Clip indicator: Indicates @ +20dBu
- OUTPUTS: Electronically balanced, connect pins 1 & 3 to screen pin 2 hot for unbalanced use
- XLR Connectors: Pin 1 screen Pin 3 -Ve Non Phase Pin 2 +Ve Phase
- Source impedance: 100 ohms
- Minimum load impedance: 600 ohms
- Operating Threshold Range: Average level +10 dBu -20dBu
- Operating Modes: 3
- Mode 1: Stereo operation. (A & B channels are controlled together )
- Mode 2: 2 x Mono operation. ( A & B Channels are controlled independently)
- Mode 3: Stereo operation with control taken from an optional microphone which will measure & control actual sound pressure level (SPL) in the venue.
- AUX CONNECTIONS: 1 & 2 Open to Mute 3 & 4 Coms (future development) 5 & 6 Warning LED 7 & 8 Clip LED 9 & 10 close to DIM - 20dB 11 & 12 Close to select level 2
- MICROPHONE CONTROL INPUT: XLR Connector Lo Z Balanced input (15V Phantom internal selection)
- DISPLAY: 2 X 20 Segment Liquid Crystal Display (LCD) Backlight & Contrast are internally adjustable 1 Green LED Power indicator 1 Red LED Input Clip indicator
- POWER: 220-240 V AC 110 -120V AC Operation Internal selection I.E.C. Mains connector Mains Fuse 220V operation 250mA slow blow. 110V operation 500mA slow blow