Matrix Mixer

Amplification is a mysterious thing. Whereas many people think of it as a simple linear process, the design of good-sounding audio equipment depends on distinct stages of amplification and attenuation, rather than on straighforward amplification alone — the charm of tube amplifiers is a case in point. A good mixer is rich in gain variation, and much of its acoustic personality comes from its “gain structure” — the sequence of boosting and cutting of the signal as it passes from input to output. [Nicolas Collins, Gain: Reflections on David Tudor]

A passive 3-by-3 matrix mixer based on descriptions in “Handmade Electronic Music — The Art of Hardware Hacking (Second Edition)” by Nicolas Collins. Get your own