DAC+ connects to the 40-pin GPIO header of Raspberry Pi 1 Model B+, Raspberry Pi 2, Raspberry Pi 3, or Raspberry Pi 4 with no need for soldering or external power.
P1: Analogue out (0-2V RMS). Carries GPIO27, MUTE signal (headphone detect), left and right audio, and left and right ground.
P6: Headphone socket signals. Pin 1: LEFT, pin 2: GROUND, pin 3: RIGHT, pin 4: GROUND, pin 5: DETECT.