Nanofader

Introduction

The Nanofader is an open-source active scratch mixer which is designed to be as simple and cheap as possible. It uses standard jellybean CMOS chips rather than expensive specialised VCAs, and can easily be assembled on a prototype board if needed.

It was originally created to allow high-quality faders to be used with portable turntables such as the Numark PT-01, but the same circuit could be adapted to a number of different uses.

Circuit description

Here is the nanofader circuit in its simplest form, with no input or output buffering or power decoupling :

This requires only