Is a DAC Worth It With Airport Express

Hi - hoping I can get some guidance on DAC and whether or not I need one. My current system:

Onkyo SR608
KEF Surround Speakers 3500SE
MacBook Pro w/iTunes

I play my iTunes library on my Onkyo receiver / KEF speakers via Airport Express.

I recently saw the PS Audio Digital Link III available at a pretty reasonable price. I know that this type of DAC (and others I'm sure) make CDs sound better, but I never use any of my CDs anymore. I listen to all my music as described above and use Apple Lossless whenever possible.

Would my setup benefit from the PS Audio product? I would imagine the setup would be Airport Extreme --> PS Audio --> Onkyo Receiver, correct?

Or is the DAC on my Onkyo fine as it is and the PS Audio just a waste of money?

Thanks so much!!!
You're correct about the Airport Extreme --> PS Audio --> Onkyo Receiver setup, using a Toslink to mini-Toslink optical cable between the Airport Extreme and the DAC. You can buy optical cables that are Toslink on one end and mini-Toslink on the other or just use a mini adapter on one end of a standard Toslink cable.

I don't have any experience with the PS Audio DAC or with your Onkyo receiver but have used three different DAC's between an Airport Express and my amp and it's quite easy to hear the differences among them.

The only way to know if the PS Audio, or any other DAC, would sound better than the internal DAC of the Onkyo is to listen to them but given the relative costs of the two pieces it's a good bet it would be.
Cg27288 - I use AE with Benchmark DAC1 driving directly power amp. You might encounter few problems:

- digital output on AE is cleaner (only 250ps jitter) than analog output but Toslink might introduce some jitter (that Benchmark DAC1 suppose to suppress)

- AE losses sync at the gap (no streaming to DAC). Benchmark recovers fast but on some other DACs it mutes first second of the track. Possible workaround is to use crossfade in Itunes.

I also use ALAC and as far as I know AE uses this format for transmission making it easier on the processor.

I had Cambridge CD4SE before - a very nice CDP but DAC is much better in every way.
A Pacific Valve Moon DAC (now "Fathom") sure made an easily heard improvement in our upstairs small system. I've not had issues with cutouts as the post above describes.
I'm using a very similar setup, only I have a the mac mini feeding directly into the ps audio instead of through the AE. I love the set up.
How much better any DAC will sound will depend on several factors. First and foremost are your ears and preferences. It'll also depend on the quality of the internal DAC in your AVR, and the overall resolution of the system. If the AVR isn't good enough to show the differences between DACs, then it won't make a difference or not enough of a difference to justify the cost.

I can't say I'd definitely hear any differences or not, as I don't know your gear.
Yes a DAC ought to be a big improvement. Audio out on Apple products have long been a weakness.

But a big factor in how much improvement you get will be how well the DAC handles jitter. After the initial model (which measured well) Airports have become notorious for their high jitter. So a DAC that handles jitter well ought to really help things out.
Go for an asynchronous type DAC and you will get an audible improvement. Not night and day but usually audible if you listen very carefully/crticallu. I have used a Benchmark DAC1 with AE and heard an improvement. It is like removing noise - everything is a little clearer with less hash.
Great responses. Thank you.

Any thoughts on my set up with the soon to be released Peachtree DAC'it?

Thanks again.
Again, it all depends on the resolution of your system and the quality of the DAC in your AVR. I'd assume you'd hear a difference, improvement and/or worth the cost is another matter that's up to the individual.

If you can try one risk-free for a period, that should answer your question. You may find that the money would be better spent elsewhere. Only one way to ultimately find out.
Anyone know if the McCormack DAC (original) handles jitter very well? Thats what I am using from the AE