The CA-2A “T-Type” Leveling Amplifier is modeled after the T4 optical photocell with a fixed attack time of ten milliseconds and a program dependent release time varying between 0.5 to 5 seconds. So now you don’t have to be confused the next time you hear the term “frequency dependent compression ratio”. This was one of the first “program dependent” designs unlike common compressors with attack, release and ratio controls at fixed values, a program dependent compressor will adjust the attack, release and ratio depending on the frequency and amplitude of the incoming signal.
Lawrence II (founder of the Teletronix Engineering Company) and distributed by Studio Electronics two years after acquiring the Teletronix brand in 1969, the LA-2A Leveling Amplifier was a tube-based compressor that applied gain reduction with an electro-luminescent panel combined with a cadmium-sulfide light-dependent resistor…known as the “T4 Circuit”. A lot of people worked very hard to create the CA-2A, so hopefully the small amount of time it will take you to install the Command Center software and download it for free isn’t a complete deal breaker. If you don’t already have a Cakewalk user account, I can assure you that signup is a breeze. Cakewalk has made the CA-2A (their emulation of the legendary Teletronix LA-2A Leveling Amplifier) available as a free download via their free Command Center software, also available on their website.