Discontinued Products
Pro VLA
Pro Two Channel Compressor with Vactrol®

"I feel the best aspect of a Switchfoot performance is the vocals." says Ryan Nichols, Front of House Engineer and Production Manager for Switchfoot. "Jon's lyrics have a true positive message. So making the vocals clear, warm and present in the mix is really important. The fans want to hear and feel every word. The MPA Gold and Pro VLA give me everything I need to make that happen." The MPA Gold™ is a versatile, two-channel tube microphone preamplifier with variable input impedance and provides warm, natural tones for vocals, electric and acoustic instruments. The Pro VLA™ is a powerful two-channel tube compressor / limiter is a multi-purpose tool for live audio engineering and studio recording. Used by professionals around the globe, The MPA Gold™ and Pro VLA™ from ART are the affordable and essential combination for any live or studio application.

The PRO VLA (Vactrol® based Leveling Amplifier) is a multi-purpose tool for audio engineering and recording. Enclosed in a 2U(3.5" high) rack-mountable chassis are two independent channels of analog leveling/compression designed to work seamlessly with any recording, sound-reinforcement, or electronic instrument setup. ART's PRO VLA circuitry is a hybrid design utilizing the latest and most advanced analog and tube technology. Using a transformerless design throughout, the PRO VLA maintains exceptional signal integrity and extremely low noise. Its VCA-less design utilizes optical electronics (Vactrol) coupled with a 12AX7 vacuum tube gain stage for superior musical performance.

The PRO VLA is a soft knee leveling amplifier by design. Although it is capable of providing a thoughougly "squashed" signal, the PRO VLA was designed to excel in areas where transparent, expressively musical dynamics control is desired. In addition to making signal levels more manageable, it is common practice to apply compression or limiting to a signal to make louder or more "in-your-face". The benefit of using the PRO VLA for these applications is in its design. By utilizing opto-electronics, the PRO VLA allows you to add more compression without sounding like you're squashing the daylights out of the signal. Unlike typical compressors which use VCA's to control level detection, the PRO VLA is very musical. The nature of its operation is much like the way your eye adjusts to light. Just as your eye transparantly adjusts to changes in light, the PRO VLA adjusts to changes in signal level.

Developed in partnership with studio and live sound engineers, the PRO VLA possesses a "sound" that is not available from any other compressor on the market - at any price! The PRO VLA was designed and constructed with the absolute best components, assuring a lifetime of quiet, reliable performance.

Vactrol® is a registered trademark of EG&G Vactec Inc., St. Louis, MO, USA

  • VCA-less Design Provides Unrivaled Musical Performance
  • Provides Superior Dynamics Control For Every Compression Application
  • Variable Threshold, Ratio and Output Controls
  • Smooth, Silky and Transparent Sound Quality
  • Variable Input and Output Gain Controls
  • Professional Backlit VU
  • Input/Output Level Metering
  • Ten Segment Gain Reduction LED Array
  • XLR and 1/4" Inputs and Outputs
  • Mastering Quality Audio Processing
  • WINNER - ELECTRONIC MUSICIAN EDITORS CHOICE AWARD
  • Five Year Warranty

Please click here for a .pdf version of the spec sheet.

Controls Input/Output level meter select switch; Attack Time select switch; Release Time select switch; Channel Active/ Bypass switch; Variable Threshold control; Variable Ratio control; Variable Output Level control; Stereo Link switch; 10 segment Gain Reduction bargraphs; Input/Output signal level VU metering
Equivalent Input Noise -99dBm (XLR to XLR, 'A' weighted); -97dBm (1/4" to 1/4",'A' weighted)
Input/Output Connections XLR (Balanced) & 1/4" (TRS)
Maximum Attenuation 30dB; 100-125VAC, 25W - (USA) Internally fused
Input Impedance 20K ohms (XLR); 1M ohms (1/4")
Output Impedance 600 ohm (XLR); 300 ohms (1/4")
Maximum Input Level +21dBm (XLR); +21dBm (1/4")
Maximum Output Level +27dBu (XLR) (RL = 100KW, THD = 5%); +21dBu (1/4"):(RL = 100KW, THD = 5%)
Frequency Response 10Hz to 20kHz (+/- .5dB)
Dynamic Range > 100dB (20-20kHz)
Attack Time Fast: 2ms; Slow: 15ms (20dB comp.)
Release Time Fast: 300ms; Slow: 100ms-3sec.
Total Harmonic Distortion <0.1% (typical)
Power 100-125VAC, 25 USA (Export units configured for country of destination)
Slope Variable: 2:1 to > 10:1
Dimensions 19"W X 6.5"D X 3.5"H
Weight 9 lbs
This is beta software, use at your own risk!
Pro VLA - Pro Two Channel Compressor with VactrolŽ