[PROBLEM] No audio from headphone jack (Pi4)

[Phil323UK]

Just to add to Kent's reply.

Raspberry Pi's 1-4 have a 3.5mm TRRS (tip, ring, ring, spacer) socket.

So you will need a cable with a 3.5mm TRRS jack to connect to your amp.

So headphones with an inline microphone should work with no problem. 

https://en.wikipedia.org/wiki/Phone_conn..._standards

Regards,
Phil.