Airport Express & optical or USB, Help please?

[edplaysdrums42]

Hi All

I am streaming my music from my imac to an airport express then into a dacmagic via the optical output, it is not possible to get my imac close to my set up hence using the AE. I've been hearing different things about the AE causing jitter (something i know nothing about), What i would like to know is the sound quality better from the USB output than the optical, I'm thinking of upgrading my dac but i have been advised that i need to sort out the issue of the AE first, maybe a mac mini but its starting to get expensive!

Any thoughts or advice would be gratefully received

Cheers Ed

 

[professorhat]

If this is the Airport Express, then the USB does not output music - it's there purely to allow you to share a printer over yout wireless network.

 

[edplaysdrums42]

Hi There

Sorry about that, i didnt explain myself properly. What i meant to say was will the sound be better using the USB input on the dac instead of the toslink from the AE. Its just that i cant practically get the imac close enough to my set up. Is the AE the weak link?

Cheers Ed

 

[Anonymous]

You can only get audio out of the optical/minijack port on the airport express, the USB is only for network printers I believe. I'm ready to stand corrected, but the jitter rate (can't remember the units it was measured in) is surprisingly low and unlikely to be too much of an issue. There are DACs that have a ram buffer in them which reclocks the audio data anyway so it becomes completely irrelevant. What is more likely to be a "limitation" of the airport express is it's maximal bit-rate (16-bit/48kHz), which while fine for lossless rips of CD quality, isn't the 24-bit/96kHz beloved of the audiophile geeks amongst us (all of my music is apple lossless rips of CD's and as I'm currently running several airport expresses, to various lower end systems, I'm loathe to pay the £20+ for 24-bit when I should be saving for some new speakers!)

All that said, I'm very happy with them and they'd be the last thing to be upgraded right now!

 

[edplaysdrums42]

Hi Fred K

You are correct on the USB output of the AE, i was gettin me inputs and outputs mixed up!. I'm not bothered about having 24bit files at this stage but maybe a good dac can completely eliminate jitter. I have heard a lot of good things about the Benchmark and Rega dac's. The Benchmark has something called ultralock, does the Rega do the same sort of thing or do all dac's deal with jitter?

Cheers Ed

 

[John Duncan]

No idea what jitter actually sounds like, but my Airport Express sounds pretty fantastic into the back of the Uniti...

 

[edplaysdrums42]

Maybe the AE isnt as bad as what some people make them out to be, Leaving the AE aside for a moment, does anyone have any preferences on the input to their dac? USB, firewire, Coax or toslink? I suppose because of the AE i'm limited to using the toslink?

Cheers Ed

 

[Sorreltiger]

Before you spend a lot of money on the trail of eradicating jitter, it might be useful to know about the rest of your kit.

 

[edplaysdrums42]

Hi There

My Set up is an Imac > AE > Dacmagic > Cyrus 6xp (soon to replaced by an ATC SIA2-150)> ATC SCM11.

To my ears the lossless files sound great but i've had a couple of people advise me that with that set up the AE would have to go and using the USB connection from imac to dac would improve the sound. I cant really afford any more upgrades at the moment but possibly a dac upgrade (i would need to sell the dacmagic). I hope this info helps

Cheers Ed

 

[Anonymous]

If you're using the Airport Express connecting to another DAC then jitter is minimal .

However, the jitter from the Airport Express' own DAC is quite high, but this is bypassed the moment you connect the SP/DIF cable.

The way you have it set up means jitter is minimal and way below the audible threshold, so you don't have to worry.

As others have said, the USB on the Airport Express is for printers only.

 

[Anonymous]

If I'm reading your post correctly, you have a concern that the AE might be having a detrimental effect on sound quality due to jitter. You're using the AE to stream from your iMac as the computer and sound system are too far apart to make running a cable a desired option.

The DAC is connected to the AE via optical, and you're question is would the sound quality be better if you were able to connect the DAC via USB instead.

As others have pointed out, the AE's USB port can't be used for audio, so the only way you could achieve this setup would be to connect the DAC to the iMac's USB port. You'd then need to run a cable to your sound system.

Probably the best way to see if this improves the sound in your opinion would be to temporarily move the iMac and sound system close enough so you can test this setup.

 

[Anonymous]

Mr Lizards advice is spot on, if you can move the iMac closer to your hifi,and compare some different dacs through different connectors,
Keith.

 

[Anonymous]

Mr Lizards advice is spot on, if you can move the iMac closer to your hifi,and compare some different dacs through different connectors, Keith.

Except the Airport Express is streaming, and produces negligible jitter, so you don't need to do anything.

Straight USB isn't the greatest even from a mac, and may well produce sound degradation caused by more jitter than that produced by the Airport Express SP/DIF. Plus, of course, you'll have a long cable (again not a good idea) and miss out from all the advantages wireless streaming gives you. Given the lack of any real benefit, I'd say it's not worth the effort.

 

[edplaysdrums42]

Hi All

Thanks for all your replies, i am aware that the USB on the AE is not for audio output, i just wondered if the USB input on the dac is better than the optical. I dont want to run a long USB cable to my system from the imac, the other option was to get something like a mac mini but i just cant afford that option right now. It sounds like i dont really need to worry, i'll move the mac close enough to my system and compare.

Thanks again

Ed

 

[edplaysdrums42]

Just put the imac close enough to my set up to compare the USB connectionand the optical from the AE and i can hardly tell any difference, if anything the optical sounded a tad clearer but not enough to get exited about.

Cheers Ed