Go with a lossless format - FLAC, Apple Lossless, etc. FLAC is the most universal one and is supported by more hardware and software.
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. 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. The authors suggested that different mixes for the two formats might be causing perceived differences, and commented:
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.
Just use AIFF which is a Mac native uncompressed file. FLAC and ALAC (Apple lossless aufio codec) are both compression schemes. Hard drives are cheap. The only thing that might be better than AIFF is WAV. WAV does not support file tagging in a way that is acceptable to most people, even though it is documented by many to sound the better. If you so choose, you can convert from one to another. Nobody seems to really understand why (if at all) one could be different than another as they end up being the same bits. Ultimately the best thing to do is rip a few well recorded cuts and in the formats that interest you and see if you can discern a diff. I was amazed/chagrined. Later you can batch convert. What ever seems to be going on, it appears to be in "real time" playing, not the ripping. Once you get the rip correct conversions are easy, albeit painful to us OCD audiophiles.
The bit about SACD is really moot. One cannot directly compare as the SACD files are not compatible with most DACs.
RW- The op stated that he was running Mac and iTunes. Foobar does not run on Mac, and in another thread recently Jax2 suggested FLAC for Mac as well. I am questioning that logic.
I am not sure what restrictions you are taking issue with. DRM or the fact that you cannot port stuff downloaded from iTunes. Neither should be an issue. An audiophile has no business buying mp3s, and DRM is the law.
Speaking of rope and hogtied, Windoz comes to mind faster than OSx. A stronger, more robust os with $30 updates vs the tiered licensing and $100 updates for windows. I run both btw...
I think the squeeze box likes FLAC to make matters more confusing. Jax2 uses SB IIRC. There are Mac players that do use FLAC. I use iTunes as a database only for the player AyreWave. I have no empirical evidence, but I question wireless transmission for listening. I use Firewire.
ALAC and FLAC compress about 40%.
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.
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.