A while ago, when looking to archive my vinyl, I invested in Pure Vinyl software for my Apple computers.
Primarily a really sophisticated vinyl capture system, the software package also features many facilities that have helped me to substantially improve the performance of my hard drive audio set up. The difference compared with iTunes is substantial to my ears, the sound has far greater depth and texture making the music far more engrossing over long listening periods.
Simply put, the iTunes Music Server feature uses iTunes as a music database and user interface, while all audio is rendered and played via Pure Vinyl's "low CPU overhead" audiophile quality 64 bit resolution playback engine.
Just like Amarra, it allows automatic SRC for bit perfect playback, it now features a properly dithered volume control as well as being compatible with Apple Remote. Unlike the cheaper Amarra package, it's fully compatible with 24/192 files as well as offering high quality upsampling as an option.
I've held off on commenting on this package as the first release of V3 was very much a work in progress and was frustrating in operation. The latest release however corrects pretty much every bug I experienced and works seamlessly with my iPod Touch. There is a slight lag, but this is quickly adapted to and switching tracks every ten seconds is not something a serious music lover does anyway.
It's worth pointing out that the original raison d'etre for the Pure Vinyl software was the digital archiving of precious vinyl collections and the software package includes a comprehensive solution including a high quality digital RIAA facility allowing users to dispense with their phono stages. The couple of recordings I have done have been very impressive (recordings at up to 24/192 again) as has been the ease of their integration with iTunes.
I have not really had the time though to even listen to vinyl recently let alone explore the possibilities with this side of the package. It's incredibly fully featured and that means, to someone like me, the learning curve is steep and time consuming. I hope to report soon once I get some time to start archiving my collection.
For me, the software is now reasonable value for the iTunes jukebox alone. I've been a heavy critic of PC audio on the forum - but this solution has led to a change of heart. The good news is that at just $229 it's also half the price of even the cheapest Amarra package - yet offers everything you find in the top Amarra solution plus a whole lot more. It's not been possible to compare them side by side of course so I am only assuming that without altering the signal, there is only so much you can do when bypassing iTunes on a Mac. It would of course be interesting to hear them side by side one day, but in the meantime anyone can download a trial from Pure Vinyl anyway should they want to experiment. It would be interesting to get other's opinions.