Hook into I2S to create an analog output

I have a smart speaker with a PCM5101A chip and would like to hook into the I2S input te generate a clean audio signal. I have tried hooking into the analog outputs from the PCM5101A chip, but have been disappointed with the result. I am looking into using something like this device (audio - How to make PCM5102 DAC work on Raspberry Pi ZeroW? - Raspberry Pi Stack Exchange) to have a separate audio signal that is not being shared with the rest of the PCB that is holding the PCM5101A chip.

Here is the pin configuration of the chip I want to steal the I2S signal from:

Screenshot-2020-02-06-at-10-17-49.png
 
The pins you need are 13 for BCK, 15 for WS/LRCK and 14 for Data. If your I2S endpoint needs a higher speed clock (like MCK) than BCK too, that's on pin 12. Don't forget a 0V connection in addition, from pin19. Keep the wires as short as practical, especially if using pin12.
 
Thanks for your reply!

I created a schematic for the solution you proposed.

  1. What about VIN? Shouldn't it be connected to pin 20?
  2. Pin 8 says "analog power supply 3.3V" on the datasheet. Do I need to connect it to A3V3 in order to power the analog outputs?
  3. About SCK / BCK, do you mean that I will only need one of those?

Screenshot-2020-02-06-at-11-31-57.png
 
I omitted to mention power. Yes you need a power source for your DAC board, it could be from pin20 or perhaps from pin8. Pin8 looks safer as pin20 could just be 1.8V on your particular PCB.

I'd suggest don't connect SCK as the PCM5101A generates SCK itself when not supplied. So connect just 3 signal lines, plus power.