ART Pro Audio Pro VLA II - Two Channel Vactrol-based Compressor - Manual (Page 4)

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INTRODUCTION
Thank you for purchasing Applied Research and Technology’s Pro VLA II
. Offering a superb level of sound
quality, the Pro VLA II
 has a unique design that will enhance the sonic textures of your audio system for
years to come. The Pro VLA II
 is one of the finest audio compressors available. Developed in partnership
with studio and live-sound engineers, the Pro VLA II
 possesses a “sound” that is not available from any other
compressor on the market - at any price! Unlike typical compressors which use solid state feed-forward
circuitry to control level detection, the Pro VLA II
 is very musical. The nature of its operation is much like the
way your eye adjusts to light. Just as your eye transparently adjusts to changes in light, the Pro VLA II

adjusts to changes in signal level.
The Pro VLA II
 was designed and constructed with the absolute best components, assuring a lifetime of
quiet, reliable performance.
The Pro VLA II
 offers:
- Two channel opto-isolator (Vactrol ® )/tube-based leveling amplifier
- Stereo linking of channels
- Master Volume and Balance control in Link Mode
- Hand selected 12AT7 Tubes
- Vactrol ® - Analog Optical Isolators (AOI)
- Non-VCA design = transparent, classic sound
- VU metering of input and output levels
- LED metering of output level with peak-hold function
- XLR balanced inputs and outputs
- 1/4” TRS active balanced inputs and outputs
- Variable Threshold & Ratio controls
- Variable Attack and Release controls
- Variable Output Level rotary controls
- 10 segment Gain Reduction LED array
- 10Hz to 100KHz Frequency Response (+/-0.5dB)
- >100dB Dynamic Range
- Low noise (-99dBm ‘A’ weighted EIN)
- Internal power supply
- 3 year parts and labor warranty
INSTALLATION
The ART Pro VLA II
 may be used in a wide variety of applications and environments. In a rack-mountable,
all-steel enclosure, the unit is designed for continuous professional use. Mounting location is not critical,
however for greater performance reliability we recommend that you not place the unit on top of power amps, or
other sources of heat and/or strong magnetic fields. The tube circuitry needs about a minute to “warm up” and
stabilize from a cold power up.