Need a safe check of my ADC PCB
First time KiCad user here, with little knowledge in electronic !
I'm starting from an existing design, a PCB that digitizes 4 audio channels simultaneously, imported from Eagle (original format) into KiCad.
Here's the original design in KiCad, ADC 1.0:
SCH ADC 1.0 (first picture) / PCB ADC 1.0 (second picture)
The first problem is that the 6-pin oscillator reference (U1, top right) used by the original circuit (DSC1101BI5-024.5760) no longer exists — it's out of stock everywhere.
So I replaced it with a much more widely available 4-pin model (SX3M24.576B10F20TNN). It seems compatible to me, and my wiring seems sound, but I'd like to get confirmation on that:
PCB ADC 1.1 (third picture)
Next, the goal would be to be able to plug 4 electret microphone capsules directly into this circuit. For electret capsules (which need power, but generally only have 2 pins total), you need a power supply (MICBIAS) plus additional capacitors and resistors to make it functional.
I got this wiring diagram to help me understand what was needed (fourth picture), with 4.4µF capacitors and 2.2KΩ resistors.
Does that seem right to you?
Based on that, I made ADC 1.2, replacing the entire bottom section:
PCB ADC 1.2 (fifth picture)
What do you think of the final logic and KiCad file? Does it seem viable to you?
Thanks!