Hi, I also had this choppy sound issue, but I was able to fix it. Now the sound is clear and loud. Potentiometer works also. - No shielded wire to the speaker, just two 0,14mm^2 wires. No ferrite toroids. - Soldered two 100Ohms resistors to the right side of 'R15' and 'R16' and connect them both to ...

@Helder: Thanks for your great job.