CMOS Noise Percussion (CB’s DIY Modular Synthesizer)

Early this morning I built a new module: a CMOS-based metallic noise generator. Inspired by this awesome Hackaday post by Elliot Williams: A series of 6 40106 square wave oscillators get mashed up with each other through a 4070 quad XOR, and what comes out sounds metallic and noisy and great! I don't really understand what the XOR is doing, but it sounds a lot like ring modulation. From what I gather this is similar to the analog cymbals on the