PHAT DAC Which GPIO are in use

… hope this helps!

this photo is helpful, but I am still not sure which pins must be soldered with when used with RPi0?, to left, pin 1,2 and to the right pins 35-40?

Terry, is this indeed correct? Need to solder only 6 pins as u specified to work with RPi0 with phatdac?

By the way, does someone know how to wire the RCA port without RCA connector … Which one from the bigger hole / smaller hole is the signal, and which one is the Ground ?

I was assuming that the small hole is the signal and the bigger one is the Ground. Anyone ?

You’re absolutely right, the smaller holes are for signal and the larger holes are ground.

Recently I received a Pi zero + a pHAT DAC, including the required male/female headers. Are the unused GPIO pins than “passed” through and can I solder wires to them for other applications? (I wish to add two push buttons to my setup).
If this is not possible, how are the other GPIO’s typically used?

Would it differ if I solder the additional wires to the bottom of the Pi, or the top of the pHAT DAC?

of course, those headers are connecting all 40-pins on the Pi… if you contact the points at the top, after soldering, then you are in effect connecting to the GPIO on the board.

… so to answer your last question, no it makes no difference compared to soldering to the bottom of the Pi.