High resolution audio on a PC questions

Get a separate DAC. Then get a separate player.

You CAN NOT discern "high definition" on a PC, no one can, blindly.

Why not?

Noise friend.

Not especially the kind you hear, it just conflicts with the signal.

Try it, you will see.

Digital streamers and players were designed by souls that all started with PC sound. And then they found ways to make music playback breathtakingly better.

That said, you are free to be happy with $0 spend.

If you’re using a current gen Mac mini (i.e. M1 chip) then I think your sampling rate is locked to 48 kHz. No matter what file you play, it will always resample to that rate if you’re using the analog out. This would be the main reason to get an external DAC. It will automatically switch sample rates in addition to possibly giving you the ability to play other hi-res formats such as DSD.

Even if a motherboard adhered to the Intel HD Audio standard, some sampling rates won’t be supported. For example, the Realtek ALC1220-VB codec on my motherboard doesn’t support 88.2 or 176.4 kHz sampling rates (I need the latter for a protocol called DSD over PCM).

Will hi-res files sound better? It depends. Some of them can actually sound worse - particularly if you get a ’remastered’ version of an album first released in the 90’s or earlier. These newer versions simply crush the dynamic range which makes the music sound louder, not better. But this is the result of poor mastering, not anything to do with sampling rate or bit depth. Really, it's the engineering that makes the recording.

The good news is that you don’t need to spend a huge amount of money to get good sound. Companies such as JDS Labs and Topping produce gear that is reasonably priced and well engineered. For example, the Topping DX3 Pro+ is $199 and you get a DAC capable of nearly all hi-res formats plus a headphone amp. It also has RCA line outs to connect to your receiver if you wanted.

If you’d like to learn more about digital audio in general, I highly recommend the following links:

24/192 Music Downloads... and why they make no sense

Digital Show & Tell

The 8-bit vs 16-bit blind listening test

You can always keep the DX3+ for a spare for when your more expensive stuff breaks.

Also, I have an Onkyo TX-8255 audio receiver (it’s completely analog). Would I hear an improvement if I ran the signal from my PC’s headphone jack through the receiver? (it doesn’t have a line out). Sorry if these are stupid questions.

Probably not simply because the signal out of the headphone jack is analog processed by much less quality internal dac of PC. You need to use the USB to get the digital signal out connect to external dac as already mentioned then receiver/amp. The difference in SQ could be night and day.

Here's a simple explanation:

DAC is the acronym for "Digital to Analog Converter"  -- in short, it takes the digital signal from the CD or music file and converts it into an analog signal that can be amplified and played through your speakers -- in other words, an analog signal just like you'd get from a radio tuner, phonograph or tape deck.  

Now ask yourself, do all tuners, phono setups and tape decks sound exactly the same? To most who are serious about their hi-fi setup, the answer is no. That's why you have forums like this where people discuss things in their search for the gear that best suits their preferences within their budget.