The Acme Opticom XLA-3 from Plugin Alliance is a stunning optoelectric leveling amplifier plugin that serves as a limiter and/or tone box. It is the software version of Acme Audio's high-end hardware unit that was originally inspired by the industry renowned Teletronix LA-2A, circa 1960s. The Acme hardware unit has become a modern classic, featuring an all-tube design that delivers a smooth natural compression. From what I’ve heard from reliable sources, the XLA-3 plugin looks, feels (with a bit of imagination), and sounds spot on.
WHAT IS A LEVELING AMPLIFIER?
According to Barry Rudolph, “The leveling amplifier is a compressor with a medium attack time, a medium to slow release time, a high ratio, and a low threshold.” As the name suggests, the general purpose for a leveler is to help maintain a smoother gain reduction signal. Without getting into a debate about the so-called loudness wars, let me simply say that this kind of compression raises the average loudness of audio by bringing up the softer stuff. The reason for the slow release time is to prevent or at least reduce a pumping effect of the compressor rapidly engaging in and out.
Check out the full Gearslutz Review of the Plugin Alliance Acme Opticom XLA-3