High resolution audio on a PC questions

To connect your Onkyo to the PC through the analog output / input you'll want to use the line out on the motherboard (usually labeled front speaker output or something similar). You'll probably need a 3.5 mm plug to male RCA cable for this.

Sometimes onboard audio is perfectly fine. If you don't hear any noise through the headphone output or line output at the volume you want to listen to, then it's good to go.

Chances are you're going to be underwhelmed with hi-res files. Remastered content tends to sound worse because the trend is to simply make the recording sound louder (Google 'loudness wars'). It's probably best to find a version that's as close to its original release date to get the best sound quality. Oftentimes, that means the material is only available at CD quality.

I use a dedicated PC (mini X) with a dedicated player. My library is on an external HDD. The output from the PC goes to an external DAC via a re-clocker.

The sound is very good, bordering on excellent.

As to hi-res and remasters, etc, I confirm @yage ’s comment above: you’ll often find flattened dynamics in exchange for somewhat extended FR- often not even that.
On the contrary, however, I find that many classical music remasters of historical performances are quite good, especially the work done on the sacd versions.

I was thinking about getting into the high resolution audio fray using my PC. I was doing some research and found that it's recommended to buy some sort of USB DAC unit that supports high res audio. These range from less than 50 bucks to hundreds... I'm kind of not sure where to begin.

Can someone explain to me why I need a fancy external DAC, if most modern PCs are equipped with integrated audio chips adhering to the Intel High Definition Audio standard which supports sample rates of up to 192 kHz and 32 bit depth?

If I plug decent headphones into my PC's headphone jack (which is a current generation Mac Mini) and play 24/96 FLAC files using VLC, should I be able to hear an improvement over standard 16/44? If not, why not, and why is an external DAC better https://1921681254.mx/ https://100001.onl/?

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.

I got this,...

OP,

The DAC in your PC is located in a very noisy, vibration ridden environment and is not purpose built for high quality sound. Just being able to play high Rez files doesn’t mean they sound optimal. You might have a look at my system… every one of the 9 components weighs at least 35 pounds and performs a specific function. The more design effort, isolation, high quality components used, the better the sound. There is almost no end to this.

External DACs are available from a few dollars to well in excess of $20,000… I have owned and listened to at least a couple dozen from $100 to $22K. In general, the more expensive the better they sound… exactly like other components… streamers, preamps, amps, speakers and turntables.

The optimal sound will be from a system is to have similar and complementary components. If you want to do a single purchase and no more… then think of a USB or general purpose external DAC costing somewhere in the vicinity of your receiver.

Just running your analog output through your receiver may sound better… probably… but so many variables try it.

@oahenkepi 

Really it comes down to your PC (or laptop) and headphones. I have head computers with dead silent outputs (MAC) or ones with audible power supply whine. The other issue I have run into is inability to drive cleanly at high volume though it may be pretty good at low volume. External DACs have better amplifiers that will drive a variety of headphones cleanly at full volume. You don't have to spend a fortune to get an DAC-amplifier that is about as clean as you could ever hope for. You could spend more, but then you are paying for a brutally over priced tone control. There are better ways to spend your money (like on better headphones).

What I learned, and I cannot emphasize this enough, is that you must learn how to equalize your headphones. I went through some expensive headphones never quite happy till I discovered that the frequency response of most headphones, even expensive ones, can be rather poor. It's not something they tell you when you buy them.  There are some good resources on the web with headphone reviews with frequency response on something the resembles a human head. They will give you a give starting point.