iPad with Airplay directly to Airport Express. Does it make sense?

[bunterharlekin]

Hi guys,

do you know if thats a good idea to get a digital signal out of my iPad? Is the output of the Airport Express bitperfect? Is the file changed in any way? I am using mostly ALAC.

 

Cheers

Axel

 

[bixby]

With 16 bit 44khz you are fine, the ae is bit perfect. All other sample rates are converted to 16/44 so not bit perfect.

As to sound quality, you don't mention how you plan to use the ae. If analog out, My bet is that the ipad itself hooked up via analog will sound better.

 

If you plan to use the digital out of the ae to go to a dac then it may depend on how good the dac is. Maybe an ipad owner who has used straight digital out form it to a dac can comment.

 

Just because something is bit perfect however, does not mean it will sound great!

 

[bunterharlekin]

I want to use it with a DacMagic. I have to admit that the direct output (analog) is pretty good. So I am not sure how big the benefit will be. I am using it with the Denon Headphone (biggest one not sure how its called).

 

[Codifus]

....I don't get it. If you have an iPad then you must be using iTunes for your application downloads and music, and any music on your iPad is in your iTunes library. Why not take advantage of the existing setup and have iTunes plays your music? You could use the iPad as a remote control for your iTunes to boot.

 

CD

 

 

EDIT: This would apply to the DACmagic as well.

 

[willmanus]

I have an Ipad and Airport Express and have attached a Musical Fidelity v-dac (equivalent to you dacmagic) to the express. To be honest it sounds much better than analogue straight out (to be expected right..) but I can't tell the difference between using the ipad to control my itunes library on the mini thus streaming apple lossless and streaming 256kbps AAC directly from my IPad but we're not talking a high-end solution here really. It sounds good enough for a second system in my opinion.

 

[willmanus]

he doesn't want to leave the mac switched on the whole time or to have to boot it up every time he wants to dance in the living room.

 

[bunterharlekin]

Thats exactly the point. I don't want to have everything running the whole time. If sound quality is not affected (or acceptably low) then I think its fair enough to leave the big system off.

 

[Codifus]

Thanks for the clarification.

 

 

EDIT: OK...had to add this:)

 

The latest Mac mini is reportedly one of greenest computers out there. You only need the screen, keyboard and monitor to set it up. Once its configured, everything can be done remotely. The monitor and keyboard would be removed from the system. I'm doing this now on a legacy, and much much less green PowerMac G4.

 

CD

 

[Miska]

For a bedroom system I'm using iPod Touch (ALAC) over Airplay to AE with optical link to DacMagic. It's really nice, convenient and the sound quality is pretty good. So I think this being quite good combo.

 

I also have Onkyo ND-S1 in the same set, in case I want to dock the iPod for charging. Works nicely, since the DacMagic has two optical inputs.

 

[bunterharlekin]

Can you here any differnces?

 

[bixby]

If your going to be listening with headphones only, don't bother with an external dac. If you are using the ipad to power a stereo system then you have the opportunity to introduce jitter by using an external dac. Yes the analog out of the ipod may not be as good as an external dac and ae, but my guess is that it will be close.

 

[poop]

Bixby your comments don't make sense to me. Why would you advise not to use an external DAC if using headphones? How would a headphone system benefit less than any other from a DAC upgrade? Introducing any DAC better than that currently within the iPad (not hard) will likely improve sound quality. Jitter is likely to be no worse than that from the iPad's DAC, if anything I'd expect an improvement here too.

 

I'd say go for the DACMagic if that's the DAC that has impressed you. In the price range, it's a pretty solid contender with good connectivity. I'd be very surprised if you didn't hear a worthwhile difference over using analogue out of an iAnything.

 

[bixby]

Axel is asking about using his Denons connected to headphone jack on ?????????? connected to a DacMagic using an Airport express as the transport source. Based on my use of a less jittery source than the AE express, (Apple TV) into a good dac with some jitter reduction merits (Benchmark ) and to some great phones via the Benchmark hp out, no I would not recommend that route.

 

Rather I would use the ipad directly to the headphones or to a good headphone amp and skip the steps that will invariably add jitter and degrade the signal. Ipads and ipods seem to have relatively low jitter out of their analog outs because they do not have to get converted to spdif and suffer the consequences of spdif transmitter/ receiver/ cables and generally sound pretty decent when run into a good headphone amp.

 

Axel does not tell us what analog source he plans to use on the end, but based on my ears I would take a good clean line out from an ipod or ipad and run it into a good hp amp and be much happier than through the jitter laden world of an ae or atv.

 

Just my experience, but you or alex are certainly open to try whatever you like. And it may be that the Dacmagic can minimize the signal damage coming out of the ae and it may feed his analog amp with a source that maybe is a bit better than the direct feed from an i device.

 

Let us know Axel, how does it sound?

 

EDIT:

 

I meant Axel

 

[Miska]

into a good dac with some jitter reduction merits (Benchmark )

 

Based on the measurement results I've seen of DacMagic with S/PDIF inputs, it probably has quite good jitter rejection. Since measurements I've seen have shown jitter values < 50 ps...

 

And it probably has fairly large buffers too, due to upsampling in DSP processor.

 

At least I've been happy with the sound using DacMagic, with both ways of feeding from iPod Touch (AE and dock). I used iTunes + Apple Remote with AE before Airplay support in iOS 4.2.

 

[bixby]

While I am sure the dacmagic sounds good with your setup I have my doubts about that 50ps figure. While we all know there are no standards when it comes to measuring jitter, it is just this sort of "spec" that misleads folks. I am sure the spec you refer to is the inherent jitter published by wolfson on their data sheet for their receiver chip. It does not however, mean that the dac as a whole is jitter free.

 

Regardless, let's just say the good dacs like the benchmark and dacmagic can have an impact on existing jitter and can produce a good result for many systems.

 

 

 

[Miska]

I am sure the spec you refer to is the inherent jitter published by wolfson on their data sheet

 

No, I refer to measurement results by Stereophile and HiFi News magazines. Both using the same type of test signal, but AFAIK, different measurement equipment. This was one of the reasons I went for this DAC, since I expected the source jitter to be on high side.

 

USB results seemed to be bad due to adaptive interface type and especially due to lack of galvanic isolation.

 

I use only optical connections and DacMagic has it's own power filter in my setup. I have not bothered doing measurements in my setup, since it sounds OK for the bedroom system and way better than the analog outputs of the devices. Wireless part disabled in AE since it has ethernet cable (STP) connected and I have a separate WLAN access point. I'm not overly critical about the bedroom system though, I'm trying to relax there and not think about work too much...

 

Edit: I don't see a Wolfson receiver chip there http://img380.imageshack.us/img380/6193/dacmagic1sy6.jpg

 

[Miska]

A little bit of critical listening (while reading emails) over AE Airplay and Onkyo dock, both over optical to DacMagic... Both with minimum phase filter.

 

With Onkyo the soundstage seemed to have more depth, AE was a bit flat. So possibly Onkyo gives less jitter on it's output.

 

This with iOS 4.2.1. Still, I think 3.x was a bit better, but hard to say since it was a while ago...