[sdiy] Module power - regulated or filtered (passively)?

[Neil Johnson]

Hi,

> A good op-amp should have an excellent power supply rejection ratio, meaning that a nominal amount of power supply noise should not appear in the audio (or CV).

Ummm... no.

https://www.analog.com/media/en/training-seminars/tutorials/MT-043.pdf

Also note the slope of the PSRR curve: -6dB/oct.  Which a simple RC
filter will neatly cancel.  In the example device given in that app
note the lowest -3dB point is around 400Hz.  A 10R resistor and 47uF
capacitor will comfortably keep the PSRR up until you get into
frequencies where the inductance of the capacitor comes into play.
You could probably make do with 10R+22uF as well depending on
application.

Neil