The ART Pro-VLA is a 2-channel Leveling Amplifier/Compressor with Optical Compression, Tube Gain Stage, and Mastering-quality Audio Path. I made some modifications to the unit:
On this unit I have modified the input, output and buffer stages with High performance Burr Brown opamps for optimum fidelity. Coupling and de-coupling is also performed throughout the circuit using premium Panasonic parts for better frequency response, lower noise, longer life and more musicality. The Vactrol is changed and the Tube plate voltage is increased to an acceptable level for the circuit. Low noise NOS Vintage Tubes are installed as a finishing touch. It has a lot of dynamic range and big bottom end. Plus I added Cinemag output transformers.
All this increases the headroom of the unit, widens the frequency response, lowers the noise and increases the detail of the three dimensional image. It also increases the speed of the attack and release times making these cool compressors useable on a broader range of applications. What I end up with is a Boutique sounding Tube Opto compressor that excels! It sounds great on bass, vocals, and even the mix bus.