The TLN-442 is a four pole low pass filter built around a Curtis Electromusic Specialties CEM 3320 chip. A built in mixer allows for three audio inputs. The filter frequency can be set using a panel mounted pot, a "one volt per octave" external control voltage, or via two external FM inputs with attenuators (one reversing). Filter resonance can be set using a panel mounted pot or an external control voltage with a reversing attenuator.
A four pole low pass filter built with a CEM 3320 was used in the Sequential Circuits Prophet Five (rev. 3) and Pro One synthesizers.
Total current draw for TLN-442 is 12 mA @+15V and 15 mA @-15V.