whats the point of a digital transport?

1) You can't just use a USB Cable out to a DAC unless its an iPad+CCK or some of those iPhones with some software tweaking involved

2) Depending on the gear downstream from there, it might make an easily appreciable difference between hooking up the iDevice lineout to the amp or getting a digital stream out of it.

For the most part, a $200 or so digital transport plus an iPod Classic gets you a digital stream (through SPDIF, and not USB - but both have their own performance advantages) with lots of storage, especially if most of your music is on ALAC. And some can be had used for a lot less money than a Touch iven they are strictly music-only devices, so you expand storage by getting another iPod.

Personally the way you can just DLNA uncompressed audio out of a Seagate GoFlex Satellite 500gb nowadays, and most headphone-related DACs (ie, those that have a headphone driver circuit built into them) have USB, and if you already have an iPad anyway, this would be the alternative that can give you both storage and a digital stream to a separate DAC.

     Quote:

Originally Posted by sobrietywarrior 

So most portable dacs take analog in from an ipod instead of a digital in?

A DAC is a "Digital-to Analog Converter".  An analog signal from an iPod is already converted by the DAC in the iPod.  An analog line-out would go straight to an amp.

Hope that helps...

Cheers!

-HK sends

    Quote:

Originally Posted by sobrietywarrior 

Oops I meant portable amp. So all LOD cables end in an analog termination?

If I am not mistaken, one of the connections in the iPod socket bypasses the on-board DAC and amp and makes a digital signal available for the dock to receive (or a DAC if you have a special connector).  The Onkyo dock looks like it takes the digital signal and allows it to be sent via SPDIF or optical to an external DAC/Amp.  This allows you to tailor your sound preferences by deciding what DAC and Amp you want to use.  Sometimes people aren't happy with sound straight from the player.  A transport/dock gives them the flexibility to experiment.

Did that help?

Cheers!

-HK sends 

     Quote:

Originally Posted by sobrietywarrior 

Oops I meant portable amp. So all LOD cables end in an analog termination?

As I mentioned, you can get a digital signal from the connector, so it should be feasable for a LOD cable to be wired for digital vice analog...I just don't know how common that is.

Cheers!

-HK sends

Quote:

Originally Posted by sobrietywarrior 

Oops I meant portable amp. So all LOD cables end in an analog termination?

Normally yes ; but keep in mind the whole concept of a dock connector which puts every pin for every imaginable purpose save for the headphone and microphone. some of the pins are for power, some for analog line out, some for the digital data transfer which can be unlocked by a chip to be used as a digital stream. So while normally the LODs we refer to have 3.5mm jacks (or 2xRCA) custome LODs bundled with the Fostex HP-P1 for example are basically the reverse of a Belkin charge-only cable, ie, they are short, data-only cables - since such portable one-box DAC+Amp devices have no traditional dock that keeps the device "standing up" as on an Onkyo NDS-1 or Wadia 170.

by definition any LOD (line-out DOC) would be terminated (and obviously started) in analog.  Otherwise it's just a DOC connection.  Line-out is a specific analog signal.
 

What they said! 

Cheers!

-HK sends