Hi,

I'm new here and have been recently introduced into the wonderful world of D/A. Naturally my research into the subject has led me here...

Considering getting a Buffalo kit, wanted to know the status of the USB vs Firewire debate? I read something about it here but is the issue fully resolved?

As for USB, if I use the receiver supplied here what am I getting vs. the XMOS (which I read you might be using...) or the Hiface? Sorry for being a noob, the past week has been a harrowing yet strangely enlightening experience for me.


Cheers

Adam

Edited by user Monday, September 27, 2010 4:46:50 PM(UTC)  | Reason: Not specified

Hi Brian thanks for clearing that up. You guys are doing great things for the audio community.

I'm thinking of running WASAPI through an XMOS out I2S into a Buffalo build (if I can ever nab me one!) with RJ45 connector. Good idea or bad?

Also, I just read here that people are getting decent sound through Realtek chips (ALC885 etc). I have an onboard ALC889a HD that I can run up to 24/192 but I've heard so many mixed things about the clocks on this thing (specifically from computeraudiophile.com), noise from the mobo etc but if no-one's encountered any issues with this I'm thinking perhaps ditch the XMOS idea and just use the S/PDIF optical out the card.

Put simply: will the Buffalo modules running optical from the 889 be a better option than straight XMOS I2S? As you can probably tell, I'm trying to avoid another soundcard

Totally out of my depth here and still confused about the best options. Enjoying the ride though!

Thanks

Edited by user Tuesday, September 28, 2010 12:53:43 AM(UTC)  | Reason: Not specified

He plans to send the I2S over the RJ45 (ethernet cable).

I cannot comment on the quality of the Realtek output, but it should be fine. If you are using optical out, it will be limited to 24/96, and on one is making TOSLINK modules capable of 192kHz anymore (which is why our module is now so limited). So, with optical, you get reduced noise, but lower bandwidth, as compared to an electrical (coax) s/pdif output.

If the XMOS module does not offer any advantage over what's out there already, we won't make them. What would be the point?

Your best bet will likely be to use the forthcoming TPA USB-I2S board, but I would recommend building it into the same enclosure as the Buffalo II. Regular I2S should be run as short as possible to avoid problems.
I would go ahead and build a B-II, use it via SPDIF and something like a Hiface for now, and leave room in the chassis to add TPA's new USB solution when it becomes available.
I am getting an Audiophilleo 2 to use with my Buffalo II DAC until the TPA-XMOS USB interface is ready.
RE Firewire, in general, both Firewire and USB have the potential to offer bit perfect, very low jitter data transmission to the DAC-one is not better than the other by nature for a computer/DAC interface-how well either will perform in the real world will depend entirely on how well they are implemented.

Thanks to all for the input.

I2S over RJ45 - bad idea.

Going to test S/PDIF optical as well as coax from Realtek (as well as both these out an old SB Live! Drive II) with a borrowed V-DAC and see what I can get out of those (heard terrible things about V-DAC USB so won't be using that input).

No more TOSLINK 192 is certainly news to me!! Hopefully this will all be rectified with the arrival of the new USB->I2S module, so like you barrows I may just have to wait. Brian, I think you guys should consider the XMOS, I guess we're all waiting for some kind of "perfect" input solution - not that USB is perfect... :)

Still the issue of clocks. I know the Live! auto-upsamples to 48khz (argh), but the Realtek does all sorts of funny things re 48/44.1 as far as I can tell from the datasheet. Also still can't tell if the Realtek's are 'true' clocks or not. I can post the Realtek datasheet as .pdf here if anyone is interested in taking a look (all the info is there) as it is all way over my head.

I really didn't want to harass you guys with noob i/o questions but there really is a lot of contradictory info out there so I definitely appreciate the input.

Edited by user Thursday, September 30, 2010 1:45:36 AM(UTC)  | Reason: Not specified

USB really can be "perfect". In my point of view, "perfect" would be defined as an I2S output from a USB input, which is bit perfect, with extremely low jitter, and which handles all bit depths/ sample rates (up to 24/192, higher might be more futre proof, but I doubt we are going to see much in the way of content above 24/192).
Right now the Wavelength Audio "streamlength" Async USB soulutions offer "perfect" performance, at least as implewmented in the Ayre QB-9 (stereophile measurements of the QB-9 have shown vanishingly low jitter).
I suspect Russ will be able to get "perfect" performance with what he is working on, as it is an async solution, and as long as the implementation is properly sorted (power supplies, clocking, buffering, code, and I2S signal transmission) it should offer the highest possible level of performance. Judging by how well done the B-II is, I am pretty confident Russ/Brian TPA will have a very special USB/I2S interface when it is done.

Kernel streaming or exclusive WASAPI on Win 7 will get you bit perfect output on Win 7 with the Azalia Realtek audio codecs.

Cheers

Thomas

IMO it's more advisable to extend the other end: USB can easily be extended, either by using standard extension cables with built-in amplifiers or by using USB over UTP extenders. Earlier versions of extenders only allowed for 1.1 speeds (1.5/12 Mbit), but nowadays hi-speed is also available. And the fully standard (5m) extension cables are totally within USBs' specs, so those will work for a total distance of 25m anyway.

Perhaps because the receiver used in the toslink kit doesn't do 24/192?

Thank you for your very helpful suggestions chaps. LeonvB, the idea of using a USB extension is excellent and I confess not something I considered!

I've now decided to use the MUX option with both Toslink and co-ax. It will then be a simple matter, given that I can try out a Hi-Face before purchase and the USB extensions are very cheap, to do a direct comparison between long co-ax, short co-ax/USB extension and long optical.