Not only that, audio CODECs have analog filters designed specifically for audio capture and reproduction, sometimes even configurable. The advantage of having

Not only that, audio CODECs have analog filters designed specifically for audio capture and reproduction, sometimes even configurable. The advantage of having a cheap tiny board is that you can build a system like a polyphonic synth with very capable voices with relative ease. And since each one has inputs too, you can interconnect signals giving a lot of flexibility (aka modular synth).