[brj]

Lately, I find myself considering the use of a laptop as a digital source instead of my initial plan to build a media PC.  With that in mind...

To the best of my current knowledge, my options for sending a digital audio signal wirelessly from laptop to digital receiver are:

1)

USB to S/PDIF conversion option
    Wireless Ethernet output from laptop
    -> Typcial 802.11x base station with USB output
    -> USB to S/PDIF converter
    -> Toslink or Digital Coax cable (depending on converter output options)
    -> Toslink or Digital Coax input on receiver (depending on converter output options)

    Examples:
        - M-Audio Transit
       - Modded M-Audio Transit   
        - MindPrint DI-MOD USB
        - Edirol UA-1D

2) Firewire to S/PDIF option
    Wireless Ethernet output from laptop
    -> 802.11x base station with Firewire output (don't know of any offhand)
    -> Firewire to S/PDIF converter
    -> Toslink or Digital Coax cable (depending on converter output options)
    -> Toslink or Digital Coax input on receiver (depending on converter output options)

   Examples:
        - M-Audio FireWire Audiophile


3) Straight Ethernet to S/PDIF option
    Wireless Ethernet output from laptop
    -> Wireless "media router" type device with digital output (Toslink or Coax)
    -> Toslink or Digital Coax input on receiver (depending on media player output options)

   Examples:
       - Apple Airport Express (Barest bones option that isn't really a server.  Would also need a good mini-optical to Toslink cable)
       - Modded Apple Airport Express
       - Slim Devices Squeeze Box (has PCM passthrough, and seems like a contender for modification)
       - Roku SoundBridge Network Music Player (also looks impressive and seems to have PCM pass-through)
       - D-Link DSM-320 (more extensive device)


4) USB/Firewire/Ethernet to digital-but-non-S/PDIF-signal option (DVI, HDMI, etc.)
    ???[/list:u]
Questions:

1) Does anyone have comments on why they might prefer one of the above methods over the others?
2) Does anyone have a particular hardware recommendation for any of the listed options?
3) Has anyone compared one of these options against the use of a good audio card (Linx, etc.) in a dedicated media PC?

I realize that these questions cover a lot of ground, but hopefully my post approximates a useful distillation of the available wireless driven "complete digital chain" options.

Thanks!

Edit 1: Added Roku SoundBridge Network Music Player

[brj]

Wow, no responses?  Is everyone still recovering from CES?

[EchiDna]

For number 4, I'm unaware of anything matching your request - for now...
although wireless video servers are not unknown and these would have your requisite connection types.

Personally I'm happy with my wired system as I have a HTPC sitting (PCI sound card) in the listening area anyway, so I can't help you with the comparison...

Empirical are offering mods to the M-Audio transit etc... and there are a few posts raving about the concept, but then, the device is not exactly a budget option...

[Jon L]

Wow, no responses?  Is everyone still recovering from CES?

These are still very mirky waters and edge-of-the-art, so obviously there isn't whole lot of personal experience with these topics.  

I guess I have some experience, as I'm running an Audio PC with Lynx card straight into my main system.  I also have Emprical-Audio modded transit, which I've tested with outboard DAC, though not in my system.

I'm also experimenting with 802.11g wireless.  Just bought D-Link DI-624 wireless router and D-link DWL-G132 wireless USB adapter.  

I still can't give you really good answers, but I'd be at least somewhat suspicious of wireless approaches as many of the fast ones actually do internal "advanced" compression/decompression of audio data while doing wireless transmission.  Hard facts about the nature of such compression is not readily available.  My D-link units claim 108 Mbps speed, which is bogus, but they do have high rates by using specialized internal compression.  I suspect other wireless solutions, even Airport Express, does something similar.  How these may affect audio quality, I don't know..

Internal soundcards, like Lynx, have their promise, but I'll just say that everything still matters, such as interconnects, power cords, etc, etc.  I also have some misgivings about PCI interface, though nothing concrete...

USB/SPDIF boxes can be made to work good, but I'm not 100% convinced as of yet.  Perhaps further experiments will reveal more.  

As far as firewire vs. USB, I'd look at what Gordon Rankin has said about problems with firewire approach on Audio Asylum..

As you can see, you just are not going to get an authoritative answer on these matters at this time from anybody.  I suggest you start with good basic platform, such as Foobar2K/FLAC, and experiment for yourself.  That's what I'm doing right now...

[brj]

Thanks for the feedback so far!

Just to be clear, in all of the above options, the only wireless part is the Ethernet connection (802.11a/b/g).  At that point, the audio data (WAV file) is still encapsulated inside of TCP/IP packets.  There should be no additional compression at that point.

The catch is stripping off the TCP/IP layer and feeding the WAV file out through a digital coax or Toslink connection (currently).  I'm thinking about trying one of the Equibit based amp options (modded Panny, etc), so no DAC will be required at all.

The "modded examples" links in my original post are pointers to Steve's work, as I know of no others currently.  (I wonder whether a Slim Devices SqueezeBox or Roku Labs M1000 might offer a better platform for modding than the Apple Airport Express.)

Thanks again!