Universal Audio LA-2A

The compressor that launched a thousand imitations - and the reissue that brought the T4 back.

Overview

As EQ (April 2001, p.114) put it when Universal Audio reissued the unit, the LA-2A was the first commercially viable electro-optical limiter. It was a new approach to gain reduction. Most compressor/limiters of the era still used tubes as the gain-reduction element. Those tube-based circuits, the magazine noted, were slow and not particularly transparent. The optical method was a different answer to the same problem, and it stuck.

Mix (October 1999, p.180) opened its coverage of the LA-2A and its sibling the 1176 by saying that "legendary" and "classic" had been worn threadbare by the industry, yet here the terms were earned. The same piece noted that among blackface units there's "quite a bit of variation." Original LA-2As are not a uniform product. They were built across a long production run, and the condition and specific revision of a given example matter enormously.

The T4 electro-optical cell is the heart of the design. Mix (May 2008, p.90) called the T4 cell "all-important," responsible for the ultra-transparent compression heard on countless hit records. Its attack, its release and its particular curve are what engineers mean when they talk about the LA-2A sound. When Universal Audio brought the LA-2A back, Mix (May 2008, p.90) reported that one engineer was among the first to open his wallet.

The reissue also came with a known workflow limitation. Mix (May 2008, p.90) noted that the LA-2A "required a kludgey procedure to stereo-link." The unit was designed as a mono leveling amplifier, and linking two of them for stereo operation was never elegant. Anyone pairing two for stereo work should expect to deal with the linking procedure.

The LA-2A goes hand in hand with the 1176 in the Universal Audio line. Mix (October 1999, p.180) covered the two together as "two audio classics" returning to market. The 1176 is the aggressive, FET-based limiter, and the LA-2A is the smoother optical one. Mix (April 2003, p.111) later observed that both the LA-2A Optical Compressor and the 1176LN Limiting Amplifier had been used on countless recordings over the preceding fifty years, with producers and engineers working with acts ranging from Sinatra to the Stones.

Mix (April 2003, p.111) reported Universal Audio's announcement of LA-2A plug-ins for Pro Tools|HD, and the LA-2A Optical Compressor and 1176LN Limiting Amplifier were both modeled for the platform. Mix (May 2013, p.70) later reviewed the Teletronix LA-2A Classic Leveler collection, noting that the LA-2A Silver was the most modern-sounding of the three variants, with a beautiful tonal range and just the right amount of warmth mixed with hi-fidelity at the top end.

Original LA-2As vary from example to example. The Mix (October 1999, p.180) observation about blackface units differing from one another is the practical warning: two originals are not necessarily the same compressor. A buyer should evaluate each unit on its own merits, and the reissue, while faithful, is its own thing. The LA-2A is a mono optical leveling amplifier built around the T4 cell. Everything else is condition, revision, and the particular curve of the cell in front of you.