mkv - headphone audio - analog??

[Christopher2222]

Need some clarification.
Do mkv's mp4's output analog or digital audio? And the 3.5mm headphone out jack is analog right?

I was playing an mp4 and during a quite passage you could hear almost a background hiss noise. So if I had it playing over HDMI I think it would be quiet right?

Similarly I was playing Shang-Chi on the dvd into my sound bar but the same thing - it was HDMI out into a analog converter to the RCA input jacks on the sound bar - when I upgraded my tv i didn't bother changing the outputs but when I realized it and changed HDMI to HDMI the quiet passages no longer had that background hiss during quiet passages, which I'm assuming is a left over image of the analog conversion. So would that be the similar thing for the headphone jack?

I do have a sound card with an HDMI output I haven't yet installed - if I install the sound card and use the hdmi output. Will that be better audio?

[pandy]

Confusing question... everything in digital file is digital, everything you can hear is analog. Some headphone sockets are able to output digital audio (optically - you can see red light if optical out i activated, there are special TOS link cables shaped as 3.5mm headphone jack).

Hiss can be outcome of poor headphone amplifier (working in D class or similar) and sometimes if filtering is not sufficient then some hiss can be audible, also it may be issue with current ripple from power supply in your audio source. HDMI is digital - signal transferred over HDMI need to be converted from digital to analog in some converter - perhaps it is simply better in one of your sources.