The White 2A Leveling Amplifier is based on a legendary vintage unit that is entirely valve based. It is a totally different device in terms of construction, where all the compression magic happens inside an optically coupled element formed by a fluorescent panel and some photocells: the famous T4A element. There are no electronic circuits involved with the compression itself. It's just a tube amplifier with photo resistors, illuminated by a fluorescent panel powered by the output signal. At the time of this invention, there weren't many ways to make an audio compressor: just variable-mu and optical. Optics was the simplest and if elements suitable for both the light emitting panel and the photocells were combined, magic happened.

Compared to another great classic compressor, the 1176, the White 2A is very simple to use, yet very effective: just adjust the peak reduction knob to get the desired limiting effect and adjust the gain knob to adjust the level of exit. The result is a smooth, warm, plump compression. It's magic leveling out dynamic ranges where smooth, consistent compression is needed.

Probably the most used compressor/limiter on vocals in the history of music, it made them stand out in a mix by giving them a consistent level and less need to touch the fader. When used intensively it brings out the personality of the tracks, also thanks to the valve output stage and its enriching harmonic effect.