I am designing an ultralow noise audio board.
On the first PSU PCB (just talking after bridge) I have a CMC to remove switching noise on diodes to undetectable levels (with plenty of capacitance for ripple and inductor to remove high frequency).
This PCB has wires going to main board. I am thinking to use a second CMC on this board so the two CMCs will be in series
My question is:
Should I worry about any impedance characteristic of CMCs? Can I use the same CMC at both places or should I use a lower impendance CMC (lets say 700R) as first CMC while using a 2.2k as a second CMC?