Nobody does it? There's massive amounts of plugins that aim to do exactly that, along with DSP-based pedals and amps. For analogue synths, the well-designed VST

Nobody does it? There's massive amounts of plugins that aim to do exactly that, along with DSP-based pedals and amps. For analogue synths, the well-designed VSTs are impossible to distinguish from the real thing in an A/B test. E.g. the Repro 5: https://www.youtube.com/watch?v=uFA_B6pP9AA https://www.youtube.com/watch?v=uFA_B6pP9AA You're right in the strict sense about analog random bias being hard to reproduce, but those are largely irrelevant when it comes to the important characteristics of the sound. In an A/B test, it is impossible to distinguish a well designed digital audio simulation from a real analog device.