Id heard good things about Decibel and was excited to find it at the App Store However, Ive run into snags and, while searching for support on the web, learned that there is a 48 hour trial version available at the developer site. I wish Id known this, as I might well have decided not to spend my $32 on this application.
First, when Ive had it working, there is no denying that it presents wonderful sound. I cant say Ive compared it directly to iTunes output because my iTunes library consists only of compressed music and I bought this app to play FLAC files on my Mac, but my computer-based audio system never has sounded better than when playing through Decibel.
However, there are some big "howevers."
(1) This is not really an iTunes substitute in that it retains no library information even when you check the "remember playlist between launches" preference. You cant just start this up and go. You need to load a playlist from files stored on your drive, and that is where the fun begins.
(2) To load the files for a playlist and, later, the saved playlist itself, you may well need to allot a VERY long time each and every time you fire up this app. My FLAC files are stored on a NAS to which my computer is connected by ethernet, and amount to about 450GB or so in storage space; they take at least ten minutes to load, whether by clicking on the directory in which they are stored or by clicking on the saved playlist. This really is very frustrating if you just want to fire up the sound system and let er rip.
(3) There are very few playback preferences and I have not figured out how to take the application out of integer mode. My MacBook Pro is early 2008 and, Ive gathered from doing research on the web, the USB ports on the pre-late 2008 Macs dont generate enough power to allow a USB DAC to use integer mode without causing an audible "clicking" sound during quiet passages. Other applications, like Audirvana Plus, allow you to turn off integer mode, which does alter the sound, but the differences are subtle and "no clicks" is better than "clicks." (A workaround is to add a powered USB hub between your older Mac and your DAC, which is what I ended up doing.)
(4) This app crashes routinely, especially if you try to do other things on your computer while it is up and running. (You wont want to shut it down unless you must, as it takes so long to reload your library, but these crashes make the decision for you.)
(5) Support appears spotty for a premium-priced app. The developer does not publish an email address and instead relies on forums for communication. However, it appears from the forum that the developer himself does not respond to all inquiries. If another user cant help out, theres no guarantee that youll get assistance.
If you have a smallish collection, or you are content to load the tracks a few at a time as you play them, you probably will love the sound quality and the ability to play FLAC files. (For those who advocate the use of Apple lossless instead of FLAC, I know the arguments for conversion, but I run a mixed PC-Mac-Linux network at home and only FLAC will play universally across all combinations of devices.) However, you should try the freebie trial first to make sure that you will get your moneys worth if you buy. I certainly wish I had. (An alternative worth investigating is Audirvana Plus, which has no trouble retrieving the same playlist instantaneously when it relaunches, gives control over integer mode and many other settings, seems more stable, and is not an incrediblely more expensive product.)