[mjn]

> can a digital filter provide a close enough approximation of that colouring that going through the analogue path is no longer necessary?

In principle yes, but it's surprisingly tricky, to the extent that even some very simple analog audio things, like '70s-era voltage-controlled-oscillator synths, are only recently able to be emulated reasonably well. The research field is called "virtual analog synthesis". I'm not sure if there's a canonical overview, but some googling turns up this 2014 PhD thesis: http://lib.tkk.fi/Diss/2014/isbn9789526055862/isbn9789526055...

[dharma1]

I've got a bunch of friends who have worked on this at some point, and I know some of the people cited in that PhD thesis. I can still hear the difference, even with state-of-the art current virtual analog emulations, like Diva.

Have to say the gap is narrowing though.

One approach I haven't seen used yet is using the latest AI/neural networks to learn and model the inherent nonlinearities in analog audio

[ShinyCyril]

I wish I had picked that for my masters dissertation - ML + DSP seems like a really interesting area!