Is iPod Digital Output Possible?

Steve is correct... the Escient is most likely using an A/D converter and converting the analog line-out into optical and/or coax digital output. I've seen a few other docks like this, even via Bluetooth (e.g. Griffen Bluetrip). The MSB is the only one that does it properly.. that I know of.

Vinnie

Bwhite - The digital iPod docking station is called the iRod, for Hot-rodded iPod. It will essentially replace all of the analog circuits in the iPod with external circuits of my own design. I will bring-out the I2S interface on the docking connector. The connector will dock with my own portable box, which will have rechargable batteries, D/A, headphone amp and analog volume control (Alps). It will use the AD1853 D/A converter and be non-upsampling. I may also try to drive a low-jitter master clock back up to the iPod, locating it at the D/A chip. I am considering putting line-outs on it as well, but it may not have the space.

Steve N.
Empirical Audio

Steve

what is the latest on our project? Have you completed a product that can bring digital out of the iPod to an external dac?

Thanks

Johnmhuntbch - I took an iPod Video apart and mapped-out the signals. The problem in this particular unit is that the signals necessary for I2S are not present. The D/A chip is run from a 12MHz clock. It is a proprietary chip from Wolfsen, cannot find a datasheet. It also uses a half-speed bit-clock. With some effort and logic, I could generate S/PDIF from this externally, but it would be jittery.

The whole point of this was to get a low-jitter I2S out of the thing. Looks like maybe a different iPod is needed. The new ones evidently use the WM8741. This I have the data sheet for. This probably has I2S going in. Not sure which iPod to buy though. This is getting expensive. I managed to put the video iPod back together and I'm giving it to my wife for use when walking the dog...

Higher priority is getting my new Formula One DAC to market right now.

Steve N.
Empirical Audio

Alpine makes a head unit for cars that does not have a CD player. It claims to take the digital output from an Ipod. So it must be possible.
Also, check out Red Wine Audio. They do upgrades on Ipods though not the latest ones. They upgrade the analog section because they claim the DAC is top notch already. One review I read said that the upgraded unit is pretty much reference quality.