This guide will provide a brief overview of the Warm Audio WA2A optical compressor, a clone of the Universal Audio Teletronix LA-2A classic levelling amplifier.
1. The Limit/Compress switch sets the ratio and knee — Compress gives you a soft knee and a 4:1 ratio, whereas Limit gives you a ratio of (around) infinity.
2. The Output gain pot controls the output level of the unit.
3. The Peak reduction pot is effectively the threshold of the compressor
4. The VU Meter selection pot changes what is shown on the meter between the gain reduction, or overall outputs of the compressor.
There are no attack or release controls on this unit as they are fixed (not user-adjustable). The attack is set to around 10ms, although this varies slightly according to frequency. The release is level and frequency dependant.