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My PC Audio Question Journey

I finally took the step of getting an external DAC (Maverick D2) allowing me to stream iTunes from my computer via an Apple TV. So far, I have only used a PC, but purchased a Macbook Pro over the weekend that will become the primary computer in the near future.

My system is the following:
Computer with iTunes (Apple Lossless)
Apple TV
Maverick D2 DAC (tube and solid state outputs)
Yaqin MC-30L amplifier
Focal 836v speakers

As a baseline, I have been unable to tell a difference between the solid state DAC output and my Elite SACD player. I am also aware that the Apple TV streams 48 kHz instead of 44.1 kHz which, in theory, is weakness in the digital signal.

Overall, I'm satisfied with my current sound, but I could be convinced to upgrade the Apple TV to an Airport Express and also to use a parallel software that works with iTunes (as long as Airplay is still supported) if I was convinced that an objective improvement could be expected in my system.

There's several layers to the discussion so I thought I'd ask my questions one at a time in an effort to keep things focused.

TOPIC 1:
The goal when ripping a CD is to create a "bit perfect" digital copy on the hard drive. Should it be expected that using iTunes will achieve this goal? If not, is there an objective way to validate that another software performs this step better? Is the primary reason that most recommendations are to not use Apple Lossless vs. other lossless formats is because it is propriatary to Apple making it the most limiting format in the future?
mceljo
kijanki's avatar
kijanki
4,410 posts
 
That's the beauty of the network bridge - computer, playback program etc make no difference since no timing is involved. PCM stream like S/Pdif coming directly from computer to DAC can be affected since computer creates timing.

Timing on the DAC side is recreated with new clock. AE is a little jittery and limitted to 16/44.1 but there are better choices. Logitech stopped making Squeezebox Touch but Sonos makes Wi-Fi Bridge.
doggiehowser
672 posts
 
The thing is that there is still inherent jitter in the devices, especially if you use a SPDIF connection again from the Sonos/Touch to a better quality DAC.

I can see the appeal of devices like the Sony HAP Z1ES, the Lumin network player and the PS Audio DS/PW DAC with the network bridge.
mwheelerk
121 posts
 
I would use XLD for the reasons stated and because it is still an active and evolving software with updates (though infrequent) and MAX to the best of my knowledge has had no updates in several years.
mceljo OP
1,351 posts
 
How does one look up the jitter spec on a given device? For example, I have had people make statements about the AE being ok for jitter using the optical output, but very jittery analog. What does "a little jittery" mean?
kijanki's avatar
kijanki
4,410 posts
 
Mcelio, Stereophile measured 258ps jitter on Toslink output. Jitter
artifacts on analog output corresponded to about 2400ps jitter.

Little jittery is very loose term. To me 258ps is still OK (requires some
suppression) while 2400ps is pretty bad. I remember reading that 50ps is
already audible and very good clocks are much better than that.

Jitter is a system thing - even 1ps AE would still suffer higher jitter
created by system noise since Toslink transitions are pretty slow. Coax
output would be faster but then you have to pay attention to characteristic
impedance of the cable and impedance matching. I have both AE and
DAC plugged into power conditioner to avoid any system noise that could
possibly come from mains. In addition Benchmark DAC1 has pretty good
jitter suppression. Benchmark DAC1 in comparison to CDP (Cambridge
CD4SE) sounded too clean at first. Many people perceive jitter also as
poor image and harshness, perhaps because noise screws-up everything.

My AE is first generation (model A1264), perhaps I should upgrade to
second generation that has lower jitter (but not always) - discussion
below:

[url]http://www.computeraudiophile.com/content/466-measurements-
first-and-second-generation-apple-airport-express/[/url]

Interesting review of latest AE:
[url]
http://kenrockwell.com/apple/airport-express-audio-quality-2014.htm
[/url]
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