confused on audio file formats

Agreed about FLAC...unless you want to use iTunes to organize your music. If so, it will not handle FLAC files. If you are using iTunes I'd suggest AIFF. 24/192 represents a sampling rate and not a file format. In this case it represents a very high sampling rate that not many DAC's can handle, and not much music is available in. Music from a redbook CD is 16/44. The high-rez music services like HD Tracks are offering music sampled at 24/96 which most of the modern DACs can handle, and depending on your system and your discrimination you may be able to hear differences from the same material from a CD at a lower rate.

Here's a thought provoking passage from the wiki on SACDs:

In the audiophile community, the sound from the SACD format is thought to be significantly better compared to older format Red Book CD recordings.[35] However, In September 2007, the Audio Engineering Society published the results of a year-long trial in which a range of subjects including professional recording engineers were asked to discern the difference between SACD and compact disc audio (44.1 kHz/16 bit) under double blind test conditions. Out of 554 trials, there were 276 correct answers, a 49.8% success rate corresponding almost exactly to the 50% that would have been expected by chance guessing alone.[36] The authors suggested that different mixes for the two formats might be causing perceived differences, and commented:

Now, it is very difficult to use negative results to prove the inaudibility of any given phenomenon or process. There is always the remote possibility that a different system or more finely attuned pair of ears would reveal a difference. But we have gathered enough data, using sufficiently varied and capable systems and listeners, to state that the burden of proof has now shifted. Further claims that careful 16/44.1 encoding audibly degrades high resolution signals must be supported by properly controlled double-blind tests.[37][38]

This conclusion is contentious among a large segment of audio engineers who work with high resolution material and many within the audiophile community.[39] Some have questioned the basic methodology and the equipment used in the AES study.[40]

Double-blind listening tests in 2004 between DSD and 24-bit, 176.4 kHz PCM recordings reported that among test subjects no significant differences could be heard. However, the youngest participant in this test was 22 years old.[41] DSD advocates and equipment manufacturers continue to assert an improvement in sound quality above PCM 24-bit 176.4 kHz.[42] Despite both formats' extended frequency responses, it has been shown people cannot distinguish audio with information above 21 kHz from audio without such high-frequency content.[43]

Of course who knows what these folks were listening on and what kind of controls the experiments had. Best thing you can do is just get a few different files and listen for yourself and see whether it makes a difference to you.

4est - As I said on the other thread, I uses MAXX to rip and Squeezeserver to catalogue and play. I started out many years ago using iTunes and still store most of my library in iTunes. I don't use iTunes to manage FLAC files. I did not suggest that either here, nor in the other thread. I made it very clear here that if the OP were using iTunes I'd suggest using AIFF. I agree with your here, as I did in the other thread: Stay away from WAV as it's more trouble than it's worth. FLAC is cross-platform, cross-device and very easy to batch convert. That is why I use it. Clear? I prefer Squeeze server because their streaming hardware (Touch and Squeezebox) are superior to the Apple alternatives (AE, Apple TV). That's my personal preference. I thought the SACD bit was interesting on face value because it refers to yet another more resolving digital format. I agree also with your suggestion to simply try the various options yourself and see what works best for you. I'd suggest that with anything in this hobby. Suggestions here or elsewhere are simply a point of departure (or not).

Well, now I'm confused! Way too many confusing ways to skin a cat.

It seems to me there would be a nice profit for someone (or company) who comes out with a simple one way solution to storing and accessing music, beit 16 or 24 bit.

For now , I have the Touch, external 1TB hardrive, and
I tunes.

If you're happy and you know it, clap your hands!

Seriously - if it ain't broke, don't fix it.

Squeezebox Touch comes pretty close to just what you are describing. It switches on the fly right up to 24/96, handles all formats, and even has a pretty OK little DAC in it to boot. Delivers low-jitter digital, and can go wireless or wired via a network. All for a bit more than $200! If you are really after the ultimate from digital just get rid of as much jitter as possible and deliver the digital signal from the Touch to a good DAC. There's are certainly ways to improve on it and get the most from it, some of which have been mentioned here. There's also ways to get the most from rips you do, again, mentioned here. In perspective, this may occur to some as splitting hairs and that's where trying it out yourself and making your own decisions comes in.

But if you like what you've got going - hell, dude, enjoy the music. Personally I'm always interested in other ways to try things and what's working for others. I'm always willing to try and listen for myself to see what works for me. It's not always the same as what works for someone else.

I agree, it's more complex than just popping a disc in a transport and pushing play. But not nearly as complex of all the more physical variables of properly setting up a perfectionist turntable rig. The real point is that the results are far more convenient and addicting in having access to an entire library of music at your fingertips, mixed and matched however you like.