This is from Paul McGowan's (PS Audio) daily blog:
"The trouble with iTunes_
Through our mini series on streaming audio we've learned how iTunes
finds and plays a track on your hard drive but we haven't yet learned
why programs that circumvent iTunes, like Amarra, Pure Music and Bit
Perfect exist at all.
If you've managed to keep up with streaming audio in the magazines, you
may have heard of these aftermarket programs that are add ons to iTunes
, and since iTunes is the single most popular music management and
playback program in the world , boasting tens of millions of users,
one would question why anyone would spend money on adding an iTunes
"helper" program like those I've just mentioned.
Here's the deal: iTunes' primary objective is to make playing music
easy and to do that Apple sacrificed the ultimate fidelity that's
important to us Audiophiles. And who can blame them? Although it's
widely accepted that Steve Jobs himself was one of us and cared deeply
about the way audio sounded in his home, Audiophiles make up only a
tiny percentage of music lovers the world over. iTunes is set up to
make sure the user experience is never in question and the net result
of that, from a high-end perspective, is an unfortunate up and down
sampling of all the music that passes through the program.
I think we've shown that once any music player begins to actually play
a track it most go somewhere to be heard: your computer's sound card, a
USB connected DAC, etc. The problem you immediately run into is one of
compatibility. If you are trying to play a 192kHz 24 bit file and your
sound card, DAC or connected device doesn't support that high sample
rate (most don't) then one of two things will happen: you'll get
nothing or you'll get trouble. In either case you won't get music at
192kHz 24 bits, you'll get something less.
Most connected sound cards, USB and network connected DACS are limited
to 96kHz 24 bits and so it is the responsibility of the interface
driver to announce the restriction to the player so things are
seamless. Make sense? The designers of iTunes simply want you to hit
play and not worry about anything else, but we're Audiophiles , and we
worry about everything! So iTunes sends the high resolution file
through a downsampler and converts it to the highest allowed rate your
connected device can handle: in this case 96kHz 24 bits. Ouch!
To make matters worse, iTunes does this with everything , both up and
down. So, for example, if you connect our upcoming entry level DAC the
NuWave (which replaces the venerable DLIII), which can accept 192kHz 24
bit asynchronous signals over USB, iTunes will upsample everything you
play to that sample rate ? even standard CDs and, unfortunately, their
upsample engine isn't all that good (none are) so your standard CDs
end up sounding digital and somewhat unmusical compared to their native
resolution. This is not ever going to be acceptable to any of us , and
if you're an iTunes user you should know this.
You aren't getting what you think you are getting.. ever.
The aftermarket programs like Amarra, Pure Music and Bit Perfect (all
MAC only programs) use iTunes only as a management tool and include
their own player, bypassing the iTunes player and upsampler. That's
why they sound so much better. Unfortunately for Windows users these
programs are not available.
One last nail in the iTunes coffin for Audiophiles: there is no support
for FLAC ? which is the single most used lossless compression CODEC for
high-end lovers today. Sigh.
So in conclusion, if you're a Windows user and are relying on iTunes..
stop. You're screwed sonically. If you're a MAC user and are willing
to convert all your FLAC files to ALAC as well as purchase one of these
aftermarket programs, you?re in good shape."