Yesterday I found a surprising way to generate noise: Feed an HPF or BPF's input with the absolute value of its output at a high gain. Depending on the filter and parameters used, it will generate white noise, brown noise, narrowband noise, regular or random bursts of noise, crackly sounds, etc.
I did this in Softube Modular (it works with the Korgasmatron II and the Doepfer VCF-8), and was wondering if someone could try it IRL and let me know if it works. I don't own anything in hardware that has an absolute value function. The two above-mentioned filters have input gain knobs that go to clipping, which helps a lot.
Is this already a known trick?