Airport Express Set-up

quote:

Doesn't that rather go against what you're saying?

Not at all. All they are claiming is that they can get a better result compared to a PCI sound card. Actually that (comparing it to a computer sound card) is also quite enlightening, because it means they are not really expecting miracles from the cheap and cheerful AE - unlike you guys it would seem!

Seriously, I wish the AE>DAC really was the equal of a Mac/DAC -- it would save me a wadge of upgrade cash.

Mr Tibbs

I don't have an AE so I am Mac/DAC and correct me if I am wrong but does not the AE pass on at only 16/44.1 ? It is recommended by Apple audio engineers and others such as the guys at Benchmark to set audio-midi at 24 bits and sample rate as high as your Dac goes, even if you are only playing 16/44 files, so wouldn't the AE hinder that? Or is it just the built in D/A in the AE that can only do 16/44 while the optical out can pass the full rate? just curious.

cheers

Mr Tibbs,

As I thought. The point is that the image is the same, and it's the DAC that's introducing the jitter. Remember that the AE sends a bit perfect file to the DAC, and, since it's difficult to encode jitter, any that appears will come from the DAC. The same goes for a PC/Mac connection, too.

The good news is that you can save that wadge of cash now!

quote:

Originally posted by avole:
Mr Tibbs,

As I thought. The point is that the image is the same, and it's the DAC that's introducing the jitter. Remember that the AE sends a bit perfect file to the DAC, and, since it's difficult to encode jitter, any that appears will come from the DAC. The same goes for a PC/Mac connection, too.

Sorry, but I don't agree with that at all.

If what you are saying is correct then I should hear absolutely no difference between music streamed via an AE > DAC-1 or the same music played direct from the same Macbook > DAC-1, yet the difference is obvious. It's the sort of difference you might expect if you were to upgrade from a good mid-range CDP to a TOTR CDP.

Assuming the bit stream is identical in both cases, then the only other possibility for a difference in sound is that one source has more jitter than the other. I've read nothing in the Stereophile test or on this thread that comes close to providing an alternative explanation.

The proof is in the pudding - do yourselves a favour, try a Macbook direct to your DAC and then you'll realise the AE has its limitations as an audiophile-grade digital source.

Mr Tibbs

As I said, you can't encode jitter. If there is a difference, it's not that. It's far more likely to be what the itunes does before sending files to the AE - itunes does impose restrictions as the article states.

Nevertheless, Stereophile concludes by saying:

quote:

The beauty of this unassuming component, however, is its S/PDIF data output, which allows the AirPort Express to assume a respectable role in a true high-end audio system.

Would love to compare with a mac, but that'll have to wait until the next job comes along...

quote:

As I said, you can't encode jitter. If there is a difference, it's not that. It's far more likely to be what the itunes does before sending files to the AE - itunes does impose restrictions as the article states.

No matter what iTunes does before sending the files (it converts them to lossless if not already lossless, BTW) the output of the AE has been shown to be bit-perfect (same a the native Mac). Therefore, the data is identical so blameless.

quote:

Would love to compare with a mac, but that'll have to wait until the next job comes along...

Please do - then come back and tell us what you hear. I promise not to say 'told you so' :-)

Regards

Mr Tibbs

quote:

No matter what iTunes does before sending the files (it converts them to lossless if not already lossless, BTW) the output of the AE has been shown to be bit-perfect (same a the native Mac). Therefore, the data is identical so blameless.

Ergo it's not introducing jitter, then, and the sound will be entirely dependent on the DAC!

Set up an imac for a friend the other day, actually, and was really impressed, especially with the windows emulation. Upgraded both the mac os and windows - flawless. I'd buy a mac for those reasons alone.

quote:

Ergo it's not introducing jitter, then, and the sound will be entirely dependent on the D

<bangs head against wall> NO, the data is identical in as much as it is 'bit perfect' IE the correct amount of 0s and 1s in the correct order. BUT, the amount of jitter present on the 'bit perfect' data is an entirely independent and separate issue! The AE and macbook push out the exact same bitstream. If we apply your logic (no difference in jitter) then the result would sound exactly the same, using the same DAC.

They don't sound the same, therefore it HAS to be down to jitter.

I'll let you have the last word!

Mr Tibbs

PS yes, mac's are very impressive and useful to have for all sorts of reasons - not just audio.

I dont have a Mac to test the above,I am using a AE with windows laptop and just wanted to point out that I have just had an Apple software update on the Airtunes/AE utility...so I will find out after the weekend if it sounds or preforms any better.

Of to work,Mike.

And also a firmware update for the A/E.

ive done the 7.4.1 firmware upgrade, what are the differences, if any?

According to Apple support, 7.4.1:

* Enables remote administration and remote access to compatible USB connected drives via Back to My Mac (except on AirPort Express)
* Improves reliability when backing up to a Time Capsule via Time Machine
* Includes recent AirPort security updates