Digital Signal from Ipod/Ipad/Iphone

[JoeyGS]

In my exploration with the world of audiophile digital source, I have currently created 2 digital sources, mainly, from the Ipod/Ipad/Iphone and the desktop/laptop computers (Mac or WIndows). Both have different digital signal chains as follows:

for the Ipod/Ipad/Iphone:

Ipod/Ipad/Iphone ---> Onkyo ND-S1 Ipod dock -----> coax cable -----> dac -----> preamp/amp

for the desktop/laptop computer:

desktop/laptop computer -----> USB cable -----> Onkyo ND-S1 Ipod dock -----> coax cable -----> dac -----> preamp/amp

OR

desktop/laptop computer -----> USB/SPDIF converter -----> coax cable -----> dac -----> preamp/amp


Now, with the above I would like to retain both sources (Ipod/Ipad/Iphone & desktop/laptop computer) but would like to reduce a component in the digital chain. The Ipod dock and the USB/SPDIF converter are 2 separate gadgets which handles the digital signal and outputs it into the coaxial cable going to the dac.

I am happy with output from the USB/SPIF converter than the Onkyo Ipod dock. Now, the questions are:

1. To get rid on the Onkyo Ipod Dock, and just connect the Ipod/Ipad/Iphone via a LOD cable into the computer's USB port and play via Itunes, will the sound quality be the same as compared to the Ipod/Ipad/Iphone connected to the Onkyo Ipod dock? That means I will play songs in the Ipod/Ipad/Iphone by using Itunes and the computer.

2. In the following digital connection chain,

Ipod/Ipad/Iphone -----> LOD cable to USB -----> desktop/laptop computer -----> USB/SPDIF converter -----> coax cable -----> dac -----> preamp/amp

Am I extracting pure digital information from the Ipod/Ipad/Iphone which is being fed into the computer?

[JackD201]

Hi Joey,

Your portable Mac devices aren't sync'ed with your iTunes? The simplest thing is to just run iTunes and keep the devices for portable use.

I don't know if I've read your options correctly. LODs are analog line out. You won't be able to route the signal to your computer except through the microphone input of the sound card. You won't be able to control or listen to the device from iTunes. If you mean, using the device USB cable, you aren't going to be able to play it through iTunes either. Connecting it and clicking on the device icon will prompt the sync option screens.

The simplest thing I can think of is to sell the converter and the existing DAC and get a DAC that has both coaxial and USB inputs. The NDS1 coax out into the DAC and the Computers' USB outs into the same DAC. Problem solved

For me LODs are DOLR (Devices of Last Resort ). The analog outputs just aren't very good.

HTH Pare

[JoeyGS]

Hi Jack,

Not all of my music are present in both itunes and in the ipod. And I get your point in just separating the portable devices from the main rig. It's just that the Ipod can also be simply hooked up into the main rig via a dock and you need not go into booting up your music server when you need a quick listen. And also, during music sessions with friends, they can just plug their Ipods into the PC music server and listen to their own music material.

I am actually using the Onkyo ND-S1 but still not satisfied with the output. This is because the PC, converter and outboard dac combo sounds way better than the Ipod, NDS1 Dock, and outboard dac combo. Mind you, the HiFace USB/SPDIF converter puts the digital rig at par with some of the best CD players out there, or even better. And I hear now that the Halide Design Bridge (another USB/SPDIF converter) also does a great job in bringing all the music data to the dac less the noise coming from the music source. There are other Ipod docks now in the market but are relatively more pricey.

Also, when I hook up my Ipod to the computer via USB cable, I am able to play the Ipod's music via Itunes. So, the question is...... in doing this, is the Ipod sending pure digital music data into the computer via the USB cable and then Itunes send its either to the computer's sound card or to another USB so its gets processed by an external DAC?

[amirm]

I am not an iTunes user but if you are able to play what is on your iPod using it, then the path is digital as USB does not carry analog audio.

[JoeyGS]

If this is the case then I would be able to compare the following setup:

Ipod/Ipad/Iphone -----> USB cable -------> desktop/laptop computer -----> USB/SPDIF converter (M2Tech Hiface or Halide Design Bridge) -----> coax cable -----> dac -----> preamp/amp

VS.

Ipod/Ipad/Iphone ---> Onkyo ND-S1 Ipod dock -----> coax cable -----> dac -----> preamp/amp

[amirm]

Indeed. Let us know what you hear as the second path has an A/D and D/A converter in it.

BTW, there are digital Docks on some AVRs such as Anthem.

[JoeyGS]

Thanks for the response Amir,

I did quite get what you meant by the "second path"....... is it the Ipod thru the ND-S1? Where does the A/D & D/A happen?

Indeed. Let us know what you hear as the second path has an A/D and D/A converter in it.

BTW, there are digital Docks on some AVRs such as Anthem.

[amirm]

The second path was your second option you listed. In that path, the output that is captured by the Onkyo Dock is analog output. This means the iPod's D/A is being used and then the Onkyo redigitizes it so that it can apply things like bass management to it. And that is your A/D conversion step.

In case of devices like Anthem AVR, they ask and capture the digital stream from iPod so everything stays in that domain until it is ready to be output to speakers and such.

[JoeyGS]

Thanks for the clarification Amir.

Is Anthem Dock out in the market?

Will let you know on the results.

[amirm]

Hi Joey. Yes, the Anthem Dock is shipping but it only works with their AVR. It is not a stand-alone product.