I decided to write up a not-so-short summary of my saga, mainly because when I was doing research on reddit, forums and review sites, I I had a hard time getting advice and finding reviews of setups that were similar to mine: my music collection is on my PC, mostly as Apple Lossless (.m4a), and played through iTunes. I also have a few 320 kbps mp3s. I have been using iTunes for >10 years and I like it because it allows me to have smart playlists based on play count, time since last play, recently added, most played, top rated etc. So for example when I get add new music, it automatically goes into the Recently Added and the Unrated playlists. I have compared iTunes to Foobar and VLC and cannot say that I can tell the difference, so I have not felt a need to stop using iTunes. Similarly, I have compared CD to FLAC to m4a and cannot tell the difference. Perhaps my equipment is not good enough, perhaps my hearing is not good enough, perhaps my DAC is not good enough, perhaps my generic power cable is not good enough. Or perhaps software and file type are all OK.
My current setup:
PC (motherboard) --> generic SPDIF cable --> Integra DTR 20.3 receiver --> Monster Standard 14G speaker wire --> B&W 683s.
I listen to music in my office (12x16) where speaker placement is asymmetrical, but I have no other way to place them. I am ok with my current setup but want to take it to the next level.
As an aside, I play guitar and bass (also a rabbit hole of chasing the sound dragon). Knowing and being used to what instruments (and a full band) sound like in real life gives me a frame of reference for music.
So I visited a couple of shops in the area and really liked the McIntosh MA252. Yes, visually first. Initially, I saw the lack of a DAC as a disadvantage, but I came around and now I think that since technology depreciates so fast, it's actually an advantage. It will retain its value better and it will allow me to change the DAC component of my setup more often.
Online reviews of the MA252 are for the most part positive, but some report a boring sound and noise issues leading to repairs or returns. I spent 30 min listening to it at the shop and I thought it sounded pretty great. However, given the uniqueness of my setup I asked to bring the demo unit home for the weekend.
I also decided, after a lot of online research, to try the EVGA Nu Audio Pro internal sound card that they developed in collaboration with AudioNote. I could've also easily gone with the Creative Labs Sound Blaster AE-9, but this one was a tad cheaper ($250 vs $350). They both have mixed reviews. I installed the card as far from the GPU as possible, and initially hooked it up to my Integra thru the same generic SPDIF cable I was using, not expecting any difference. To my surprise, even the card's digital output was noticeably better than the onboard one. The headphone amp, as tested with B&W P7, was miles ahead of the Integra. You could discern the detailed tone of each instrument no matter how busy and compressed the song. The bass was fast and proudly present. A true joy. I guess you don't know what you were missing until you see what your headphones are really capable of. Quite fantastic really and much better than their wireless sound quality, already very decent. More info https://www.evga.com/products/product.aspx?pn=712-P1-AN21-KR
One last layover before reaching our final destination. I then switched to an Audioquest Golden Gate RCA interconnects between the audio card and the Integra receiver. So this effectively switched the DAC from the 10 year old Integra to the EVGA Audio Nu Pro. This also brought a noticeable improvement in sound quality, as expected. It made me think perhaps I'd be happy simply by adding the audio card to my setup. I was wrong.
Next came the test of tests, the culmination of weeks of online research and in-store testing, the reason why you are still reading and the trial that would put my modest existing setup to shame or, alternatively, save me thousands of dollars: EVGA Nu Audio Pro --> MA252 --> 683s.
To reiterate, there are 2 aspects that make my setup quite unusual:
I've found that audiophiles very rarely use internal audio cards. Yes, a DAC of similar quality would probably be cheaper, but then I'd need extra desktop real estate and 2 additional cables (interconnect and power).
The MA252 is usually paired with better, more expensive speakers. None of the reviews I found used B&W 683s.
It was also a slow process of upgrading many individual elements in my chain and appreciating the sometimes not so subtle differences, while each time considering if the improvements were worth the cost of each component. Fun weekend project!
Finally, I armed myself with a Talisker and I picked a couple dozen songs that I felt I knew well enough to notice differences and that were of varied characteristics (some acoustic, some loud, some electric, some very vocal, some bassy, etc). I played them one last time with my Integra before switching to the MA252.
First impression: perfect sound. Perhaps the greatest compliment I can give it is "major noticeable difference". Great detail, stage, separation, bass, balanced. After one hour of listening to my favorite music, I was still hooked and wanted more. My ear did not just adjust and get used to the better sound, a most welcome surprise. I was still enjoying each instrument on every song and finding details I hadn't heard before (or was I just paying more attention to it now? Nah, it was the amp). I also found an unrelenting urge to pump up the volume and no need to turn it back down, no matter the type of music. Is this what they mean by "low fatigability"?
Really, I wondered, how much better can this get? Well, in one of the shops I did listen to a $25K D'Agostino integrated paired with a $12K Audio Research CD player and proportionally expensive speakers. I guess that did sound better, but for an absurd amount of money.
Hissing issue: I had read multiple forum posts complaining about this and leading to returns or sales of the MA252, but during the first couple of hours of listening I completely forgot about it and definitely did not notice it. Once I specifically tested for it by muting the source and pushing the volume up, it was VERY obvious. With my 683s, it started being noticeable at 70%, at 80% it was unmistakable, at 90% it's annoying and at 100% it's straight up scary. I tried switching cables, changing the position of the amp, changing inputs, changing power cords, and plugging straight into the wall outlet, but nothing worked. That being said, my usual listening volumes would be 30% for night listening, 40% for daytime listening, and 50% for home alone, scotch-enhanced, balls out listening. As an experiment, I turned the amp to 90% where the hissing was very clear and turned down the computer volume. I couldn't go much higher than 20% on the computer without being too loud for my taste. So yes, the issue is there, at least on the demo unit (unknown manufacturing date). It is not subtle at higher volumes, but fortunately it only happens at volumes that I would very rarely use, and most of my music is loud enough to drown it. I did check the audio card with the Integra at full volume and it did not have any background noise. The hissing issue is also present when using headphones, ruling out the speakers or speaker cables as the source. It was worse because with headphones, the issue starts becoming apparent at 60%. I called McIntosh and they said it's normal for this unit given how many components are crammed into such a small space. They said that if I listen to music at levels where it's noticeable, then this unit is not for me and to get a MA352 which reportedly has much less background noise. I was hoping it'd be an issue with this unit only, or with older models only. I guess I'd have to order a new one to see if they fix whatever issue is causing the noise.
Speaking of headphones, I got to compare the Audio Nu Pro headphone amp vs the MA 252. Since switching between the 2 was quick and easy, I was able to compare more objectively. Made me wish I could go back and forth as simply between the Integra and the Mc. Anyways, as great as the EVGA amp is, the MA252 beats it. More detail at every frequency, more oomphy bass. I'd probably be happy with the EVGA as far as headphone listening goes (i.e., the improvement in SQ is not proportional to the cost). But if you're getting the MA252 anyways, the headphone amp is the cherry on top. Except for the hissing issue that makes it unlistenable after 60-70% volume, especially for quiet genres.
The final test was going back to the Integra after spending a few days of the McIntosh. What I had previously described as perfectly ok sound was now lacking life and much less engaging. Music became a background. Higher volumes were piercing after a while. It was like losing music lost a dimension. Using the headphone output left a similar impression. I truly didn't know what I was missing. I went back to a couple of stores and auditioned a couple other amps in the same price range, including the M33, Atom Unity and STR, usually to more expensive speakers and in a better room than mine. I did not feel any of them were better than the MA252 and so decided to buy one. ETA is 4 weeks.
TL;DR: after much research and spending a few days trying one at home, I decided to pull the trigger on the McIntosh MA252 for my PC + B&W 683s setup.