The LA-2A Leveling Amplifier is an audio compressor invented by James F. Lawrence II, founder of the Teletronix Engineering Company in Pasadena, California in the early 1960s.
The LA-2A is a hand-wired, tube-based, compressor.
It uses an electro-luminescent panel together with a cadmium-sulfide light dependent resistor to provide gain reduction, which, in the LA-2A, is called the T4 cell. The properties of the T4 give the LA-2A its unique character by making it an entirely program dependent design. The attack time is 10 milliseconds and the release time is about 60 ms for 50% release and 0.5 to 5 seconds for full release, depending on the previous program material.
Three versions of the LA-2A were made until 1969.
The LA-2A was inducted into the TECnology Hall of Fame in 2004.
