Teletronix was an American manufacturer of audio equipment that was founded in the 1950s by James F. Lawrence, an electrical engineer who specialised in developing vacuum tube-based technology. In its early days, Teletronix produced a number of innovative and highly regarded audio processing devices, including the LA-2 Leveling Amplifier, which became a classic piece of studio gear and was widely used in recording studios around the world. The LA-2, also known as the “Silver Box,” was a tube-based compressor/limiter that featured an electro-optical attenuator and a unique gain-reduction element that imparted a warm, musical character to the sound. Teletronix was acquired by Universal Audio, another prominent manufacturer of audio equipment, in the late 1990s.