My experience after lost of 20k$

This is a silly thread, even for Audiogon.  What you need for PC audio is knowledge.  A PC is a fine front end for digital audio, and doesn’t really need to be expensive, although your choice of DAC may be. But there is a lot of knowledge needed to build and configure to get there.  And knowledge not to point at scapegoats and try shortcuts like buying expensive USB cables.  That’s not the way.  

OP's post is difficult to respond to--he/she gives no idea what was tried, what failed, what sorta/kinda worked. What was the gear? What types of files? 

As another poster here put it, my experience w/PC Audio was radically different from OP's. For life reasons to lengthy to list here, I put my high-end 2 channel system in storage in 1991 (it's still in storage). I set up a home office in the late '90s and had a 3rd career there. From day-1 I had computer speakers + sound card, but never regarded this as true audio (ie, to be optimized/perfected).

That all changed in 2006 when I bought a full desktop audio system recommended in STEREOPHILE (Stello DAC; NHT sealed/powered monitors + sub), a huge/audible upgrade. I gradually began experimenting with computer files, ripping CDs to the HD.

I've upgraded my system continually/intensely since then and now have what I consider a very good 2 channel set up on desktop (preamp + Wyred4Sound ST500 amp + ATC SCM 12 Pro passive monitors). This is crossed over to a single SVS sub using a Marchand external/electronic crossover (XM44). This system is also heavily optimized for headphone audio--not the highest of the high end in that regard, but getting up there.

I do a lot of streaming of music while I work; and for close listening via monitors or headphones, typically use ripped .wav or .flac files on HD (most are 44.1, not high-rez).

IMO, the one ingredient that is the "secret sauce" of good PC audio is the DAC. Without a really ideal-sounding DAC, you can't get to the true quality of your speakers/monitors, headphones & amplification. I own several multibit DACs made by Audio GD. The NOS DAC in particular (NOS 19) totally changed my desktop audio sound quality. My "DAC journey" pretty much ended there.

Is all the the equal of the big system I had set up in the '80s (including vinyl, tube amps, tube preamp)? No, of course not. But for a small home office, it's very good & evolved audio. And when it comes to headphones (which didn't even exist back then), it's very high quality. 

@desktopguy  Excellent post with quality points. Wish we had more posts like yours (across all threads). 

In general, don't understand why folks say PC audio sounds awful. I have a hard time with hiss and pop of vinyl. + Bass from vinyl systems can cause feedback at concert level volumes + digital bass just sounds better to me. I have thoroughly enjoyed 24Bit recordings (if truly a master recording not up-sampled)  although a direct to disk recording is very good just not as good imo.  I have a windows based $600 pc with JRiver software (wonderful software). the ripped data or HD goes to a PS Audio/Cullen modified DAC (fairly cheap) via an high end Audioquest TOS link. Yes at very rare times the TOS looses sync for a few seconds but sounds better than USB stuff I tried (AR DAC 8 was good but not as good for me). For $20K something not right....