Why USB - how about ethernet?

[dpaws]

Evening Guys - I'm hoping some of the technical gurus could enlighten me as to why we're using USB as an interface between devices and not creating a mini closed ethernet network between two devices? I'll elaborate...

 

I have the Meridian Sooloos Control 15 music server, essentially an ATX motherboard running embedded XP and outputting digital audio stream via the USB bus to a dedicated internal audio board via a "proprietary" interface.

 

At the same time that this Control 15 server was under development, Meridian also had the ID40 card for its top of the range processor. The card accepts an ethernet input and converts to digital audio output stream. (Versions of the same card are used in the 861v6, 808.3, 818 and MS600 models in the Meridian range)

 

Why would a manufacturer chose data transfer of a "delicate" digital audio stream over the USB bus rather then sending out data packets via ethernet directly to a remote card such as the ID40? Specifically, why develop a new internal audio board rather than re-jigging the existing ID40 ethernet board and connecting by a closed network?

 

Are we considering the lesser of two evils, have I missed something? I had assumed that if a digital audio stream ever touched an interface it was vulnerable to jitter where as packet data over ethernet by definition is immune?

 

The power supply to feed the ethernet card would be independent and thus free of the noise on the contaminated PC supply. (I assume we can negate the need for a router/switch in between as a crossed network cable achieves communication.)

 

The music server still needs to connect to an external network / internet for album data retrieval and remote control via iPads etc. Surely an additional network card or wireless card would facilitate this requirement?

 

Thanks guys...