DBaldock9
Headphoneus Supremus
It doesn't have a TRRS jack? How does the N3 "support CITA standard headphones" (quote from the Cayin web page)?
Well, without having looked at the Cayin N3 web page, I had tried using this cable, which works to control Play/Pause & Volume on my Nexus 5 Android phone, and neither mode switch position allows any control of the N3 (Play/Pause or Volume) [ https://www.aliexpress.com/item/Wit...5-se425-se535-Se846-LN004900/32702459857.html ].
However, after reading your comment, I did try my VE Monk+ 3-Button Controller version (works with any CTIA terminated Android device ~ with Volume Control for all Android devices), and it did work for single button control. In other words - pressing any of the three buttons Once, will Play/Pause; pressing any of the three buttons Twice quickly, will Skip FWD to the next track; and pressing any of the three buttons Three times quickly, will Skip BACK to the previous track. But the Volume buttons do not control the volume [ https://www.veclan.com/engappliance_sel_one?eng_ApplianceVo.eac_id=4 ].
I guess we need to hear from @Andykong or @CayinSupport to know whether there's a simple digital input (to read presses of a single button), or an ADC input channel (to be able to read the the varying resistances which create a voltage divider when used with multiple buttons).