Best Ways to Connect an Asus X870 MAX Gaming Motherboard to a Sony TA-AN1000 Receiver

Honestly, unless you're using super high-end speakers, you probably won't notice a significant difference between HDMI and a regular 3.5mm connection. Just make sure your audio cables have good shielding to avoid noise. If you want digital sound without HDMI limitations, consider getting a USB sound card that can output optical or coaxial.

You might want to try using the audio out instead. Ideally, you'd connect it via SPDIF for a better audio experience, but since your motherboard only has a header for it, you'd need to get a bracket with an SPDIF connector to link to the motherboard header. It's a little extra setup but worth it for the quality.

HDMI is generally your best bet, but if it's just seen as a display, you can still use the audio output from your PC. Just grab a 3.5mm to RCA cable; they're super common and should work fine if you don't have too much interference. If surround sound is a priority, stick with HDMI, especially if you're connecting through a TV as well.