Schematics and general files:
Stereo audio DAC schematics:
Disclaimer: Please note that PINE64 SBC is not a "final" product and in general certification is not necessary. However, PINE64 still submit the SBC for FCC, CE, and ROHS certifications and obtain the certificates to prove that the SBC board can pass the testing. Please note, a final commercial product needs to perform its own testing and obtain its own certificate.