A dual VCA on a chip, first issued by Curtis Electromusic in 1987. It was designed as a high-performance and physically smaller alternative to the 3330. Being that it had only 8 pins, only one control voltage input for each onboard VCA could be provided. Accordingly, there were two models: the 3381 provided a linear control voltage input, and the otherwise-identical 3382 provided an exponential input. The design offered an improved signal-to-noise ratio over the 3330, and onboard circuity for suppression of control voltage feedthrough. As was the case with the 3330, it was necessary for the designer to provide external buffering for the output of the gain cell.

The 3381 and 3382 were targeted both for use in synths and for high-end audio equipment. Only a few synths used the design, including the Prophet-VS. In the 1990s, Synthesis Technology was able to secure a supply of 3381s, and Doepfer used this supply to offer several models of modular VCAs that used them. However, this supply has since been exhausted and Doepfer discontinued those VCA models in 2008.

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