What PRE OUT in my Fosi device？

• A pre-out allows you to connect with a powered speaker/subwoofer or an external power amplifier with the passive speaker. Please refer to below tutorial videos.
• Please refer to the video through the link. https://youtu.be/WhYpHkovCWs  (2:44 PRE OUT)
• PS: This pre out is a 3.5mm stereo jack.

If you have any questions or concerns, please don't hesitate to contact support@fosiaudio.com.