Pc -> Dac, How ?

[tritosine]

that xmos thing looks very very nice if you have a good D/A idea too. Hopefully its around 150usd?
I really hope we see some decent D/A ideas , because this interface talk is getting old

[NeoY2k]

This XMOS thing is great news! We could now more easily develop audio interconnection. The remaining thing would be to develop a low latency audio network for pro uses (it has Ethernet, Audiorail skipped the MAC and TDM audio data... Straightforward, cheap, works...).
When I see the code for an i2s receiver (given as sample code), I can't stop thinking: just setting the registers of a TC Dice or stuff like that is more complicated.

Plus you can do anything you want with that thing!!!!

[tritosine]

I would make a (cough) digital (cough) crossover . I would keep the 'pro' and 'oversample' , 'upsample', 'ringing' words out of it , as these are gathering very bad meaning nowadays...

-Journalists, you know...

[jkeny]

It strikes me that these ICs could form the basis for a nice DIY project(the non-BGA ones anyway). Come to think of it, even the BGA ones can be used if a protoboard would be suitable SchmartBoard - The world's best circuit prototyping system Expensive at $45 each but maybe?

So who's going to be first to put one together? USB or Ethernet?

[Telstar]

<snip> I like this thingy

Originally Posted by anbello

USB audio class 2.0 is capable of 8 x 24/192K channels

I hold my opinion until i hear how they sound, compared to firewire. The real bandwith is a little lower in usb 2.0 (theoretically higher), but in practice the sharing common to all usb devices can cause issues for critical tasks as realtime audio. In the worst case a dedicated pc is using at least another usb device (mouse or keyboard), usually two or three (VFD, IR).

When USB audio class 2.0 drivers will be available for all OS you can use these kind of device without proprietary drivers

Do you know when that'll be? I have Windows7, but I dont think it supports usb 2.0 audio yet. Maybe even linux will move sooner.

[Pjotr]

Originally Posted by Telstar

I hold my opinion until i hear how they sound, compared to firewire. The real bandwith is a little lower in usb 2.0 (theoretically higher), but in practice the sharing common to all usb devices can cause issues for critical tasks as realtime audio. In the worst case a dedicated pc is using at least another usb device (mouse or keyboard), usually two or three (VFD, IR).

FYI, I am encountering no issues with my EeePC (1.6 Gig Atom CPU) running XP-Home, over USB 2.0 with my Musiland USB converter. Also connected are an USB mouse and USB IRC. Even playing a CD from a hooked up external Plextor USB DVD drive performs flawless. But ok, playing a CD doesn’t take the USB to its limits.

[Telstar]

Originally Posted by Pjotr

FYI, I am encountering no issues with my EeePC (1.6 Gig Atom CPU) running XP-Home, over USB 2.0 with my Musiland USB converter. Also connected are an USB mouse and USB IRC. Even playing a CD from a hooked up external Plextor USB DVD drive performs flawless. But ok, playing a CD doesn’t take the USB to its limits.

Good to know
But you are not using 8 channels with ASIO, which are for me requirements for my crossover. I think some proprietary (or good opensource) asio drivers are needed, I dont consider asio4all up to the task.

[anbello]

Originally Posted by Telstar

I hold my opinion until i hear how they sound, compared to firewire. The real bandwith is a little lower in usb 2.0 (theoretically higher), but in practice the sharing common to all usb devices can cause issues for critical tasks as realtime audio. In the worst case a dedicated pc is using at least another usb device (mouse or keyboard), usually two or three (VFD, IR).

I'am not an USB expert but on ICH8 datasheet (an example of what you could have as I/O controller Hub on your PC) i read:

"The ICH8 contains five USB full/low-speed host controllers that support the standard Universal Host Controller Interface (UHCI), Revision 1.1"

"The ICH8 contains two Enhanced Host Controller Interface (EHCI) host controllers which support up to ten USB 2.0 high-speed root ports. USB 2.0 allows data transfers up to 480 Mb/s using the same pins as the ten USB full-speed/low-speed ports. The ICH8 contains port-routing logic that determines whether a USB port is controlled by one of the UHCI controllers or by one of the EHCI controllers"

I Think this implies that if you have up to 2 high-speed devices and 5 full/low-speed devices there is no sharing of bandwidth and each devices talk to his UHCI or EHCI.

Example:
1 USB audio 2.0 device <--> EHCI1
2 USB 2.0 external HD <--> EHCI2
3 USB 1.1 mouse <--> UHCI1
3 USB 1.1 [other device] <--> UHCI2
...

Do you know when that'll be? I have Windows7, but I dont think it supports usb 2.0 audio yet. Maybe even linux will move sooner.

I don't know when but i think that if there will be enough device of this kind microsoft will develop the driver and so will do some linux developers (i hope so)

Ciao
Andrea

[dwk123]

That xmos USB2 kit does look very interesting. More of a general purpose cpu environment rather than an FPGA which might make it a bit more accessable. If the price on the USB2 kit is low enough, it definitely seems to be worth a look. Maybe time to research the status of USB2 audio drivers in Linux.

[anbello]

Latest news on the XMOS solution:
XMOS USB Audio 2.0 reference design provides highest quality audio solution | XMOS

"The design works with the Mac OS-X 10.6 (Snow Leopard) Audio 2.0 native class driver, and XMOS has teamed with Thesycon to provide Audio 2.0 Class driver support for Windows."

Nothing on linux front.

They sell the board here:
https://www.xmos.com/products/develo...kits/usbaudio2

Ciao
Andrea