You Can DIY! Building a Guitar-Controlled Synthesizer: VCA & VCF

Ethan Winer offers his fifth Guitar-Controlled Synthesizer article where he describes how to make two key modules needed by every analog synthesizer: the Voltage Controlled Amplifier (VCA) and Voltage Controlled Filter (VFC). This article explains two different VCA circuits, with a simpler one that works fine for one-off projects where precise unit-to-unit repeatability isn’t needed, and a second circuit similar to the VCA in the original Moog synthesizers. This article was originally published in audioXpress, August 2022.

The August 2022 issue of audioXpress, Acoustics Focus, gives a unique overview of market trends in acoustical products, with great articles on Acoustic Diffusion, Distributed Subwoofers for Room Modes, and Reverberation Control and Measurement. Michel Nieuwenhuizen proposes an improved microphone preamp for condenser microphones, Aren van Waarde builds a minimalist preamp using only discrete transistors, and Ethan Winer shares circuits for VCA and VCF analog synthesizer modules.

THAT Corporation, the leading vendor of high-quality audio integrated circuits (ICs) from Massachusetts, announced the appointment of industry veteran Denis Labrecque as IC Sales Manager. In this role, Denis will lead THAT’s global IC Sales organization, as well as manage THAT’s worldwide network of IC distributors and representatives.

Sound Semiconductor announced single and dual channel VCA additions to its product lineup, the ProCircuit SSI2161 and FatKeys SSI2162.The ICs are part of a family of affordable high-performance VCAs from the company, now offering a single, dual and quad versions. The SSI2164 offers four VCAs in a compact SOP package with lowest cost-per VCA, while the new SSI2162 is a versatile building block for high-performance audio applications, and the single-channel SSI2161 provides lowest noise.