Multichannel DSD256?

[janosch simon]

HM HM HM HMMMMMMMM then it should be possible with even the raspbery pi 3??? D:
where is the bottelneck?

 

[Dimdim]

The bottleneck is that the RPi has absolutely no support for native DSD via its I2S pins. It can only do DoP and that for only 2 channels and up to DSD128 (in case of kernels that can support 384KHz PCM).

It cannot do multichannel PCM so naturally it can not do multichannel DoP.

 

[janosch simon]

bummer hmmm and those xmos usb converter thingys they can do nativ dsd? but only 4 channels?

 

[Dimdim]

That's right.

 

[janosch simon]

damn HMMMM yesterday i played a 5.1 sample sacd and mosts of the music came from the front 3 so i guess the 4 setup is front left and right and back left and right? so center is missing is badddd

hmm perhaps exasound interfere here exaSound Audio Design > e38 > e38 DAC Specifications hihi :d

 

[Kal Rubinson]

any of you guys heard dsd256 live? the files i bought from channel classic i cant play yet only 2 chanel if i give my dvd 3910 a multichanel dsd file it dont plays it GRRRR

Sure. I have and play many of them using an 8 channel (not DIY) DAC: exaSound e38.

 

[janosch simon]

damn lucky you if im right the exasound was born here or?
perhabs he gives little back to the diy community hmmm can you tell us how dsd256 sounds compared to dsd64?

 

[Dimdim]

Edit: it looks like the exaSound does indeed do multichannel DSD

 

[zarandok]

What about this receiver: XMOS Multichannel high-quality USB to/from I2S/DSD SPDIF PCB - DIYINHK?

 

[wealas]

No DSD support, you have to write a firmware to do that.

 

[kazap]

Sure. I have and play many of them using an 8 channel (not DIY) DAC: exaSound e38.

Can you confirm if the e38 can achieve multichannel DSD256 over USB please?



The manual says it can do eight channels of DSD and that it can do up to DSD256 but it doesnt actually say if can run eight channels at DSD256.

 

[Kal Rubinson]

Can you confirm if the e38 can achieve multichannel DSD256 over USB please?

The manual says it can do eight channels of DSD and that it can do up to DSD256 but it doesnt actually say if can run eight channels at DSD256.

I can only confirm that it will do 6 channels because that is all that I can play and all that I have in the way of source files. It is entirely reliable.

I could make up an 8 channel output to test it for you but not for a couple of days.

 

[kazap]

...... unfortunately im not aware of any device that can provide i2s transfer with 768khz i believe is needed for quad dsd? hmmm gmm hmm D:

I still think using PCM for multichannel has many advantages over DSD:

• smaller downloads
• well supported on many platforms
• easy to do computer DSP and volume control

Its great your experimenting with multichannel DSD and trying to extend the boundaries.



I think there might be a way to work around the USB limits for streaming DSD.

Perhaps one example of a hack to think about adapting could be something like:

1. Windows PC (if its powerful you can even try processing 44.1/16 up to 5.1 x 256DSD)
2. Foobar running DSP's and VST's for multichannel native 256DSD out
3. USB 3.0 powered hub ebay
4. Clean 5v power into hub and cut the PC 5v bus on the USB cable
5. three (for 5.1) or four (for 8 channels) usb xmos native-dsd 256 boards eBay
6. Ians multichannel FIFO to sort out the timing

I dont use DSD and have no idea if that's a workable proposal. Good luck. Don't give up.

 

[janosch simon]

hmmm hmmm not so easy project thx for the suggestion i hope that one of the guys mentioned earlier in the thread can say something if they have a product in development and your right for just testing its a big hussel. multichannel pcm is already on bd and dvd no need to test it. i want DSD256

cheers janosch

 

[wealas]

Now there is a new kit from MiniDSP that claims 8 channel native DSD support up to 256 MCHStreamer - USB Audio Swiss-Army knife

 

[HpW]

Now there is a new kit from MiniDSP that claims 8 channel native DSD support up to 256 MCHStreamer - USB Audio Swiss-Army knife

Not that beef IMHO...

while no slave mode option for input master clock sync and no USB isolation's.

But now SR with 8 x 384kHz possible

Hp

 

[wealas]

Beggars can't be choosers, this is the first interface I've ever seen that supports multichannel DSD out of the box unless you consider the BeagleBone + botic out of the box.
At least now you can add Ian's McFIFO and get the rest, before there were no options for 8 channels.

 

[maxidcx]

Hi this is both exciting and surprising...
How the hell did they solve the limitation of the 64Mbit/sec for single USB isochronous endpoint which is the foundation of the XMOS library...

but reading the user manual it seems they do it,
example they claim TDM24 at 32bit for 96khz which is 73Mbps slightly above 64
another one PCM384k in 24bits for 8 channels = 73mbps again
and still 8 channels DSD256 = 8*4*44100*64 = 90MBps...

even if they found a trick to tweak the XMOS USB library, I m still skeptical for IOS.
On the Apple web site they clearly state that UAC2 Implementation is limited to 10 channels 192khz
Technical Note TN2274: USB Audio on the Mac

anyone could double check this ?

 

[wealas]

Hehe, you're right, on IOS the board only supports DSD128.
If you read the user manual closely you will see that DSD256 is only supported via native DSD (tiny note in one of the tables) but it also says that IOS only supports DSD via DoP (which is not a board limitation).

Also, due to the output pin mapping, this board won't work with Ian's McFIFO for PCM and DSD output, even for 2 channels. You can wire it for either PCM or DSD due to the fact that Ian uses the same pin for PCM SD and DSD Ch 2 while the miniDSP board uses the same pin for SD and DSD ch 1.

I also do not see any dedicated clocks or clock generators on the board (no mention of it in the datasheet either), wonder what they use, maybe I'm not looking hard enough,

 

[maxidcx]

Hi Wealas,
yes I recall this note 2, but they do not explicitly say if OSX can play or not a DoP128 (which requires the same bandwidth as DSD26), so mystery remains for me

There is only one crystal on the board and the 22/24mhz is either provided by a PLL like CS2100 or a cheap frequency generator like Si5351A. guessing.

the pinout DSD/PCM is also not compatible out of the box with a Sabre multichanel DAC and an external mux is required but they do not mention which of the GPIO reflects a DSD_ON signal...

Also the lack of a slave mode for AKM type of synchronous DACs with local crystal is a bad thing...

So, happy to see that Minidsp modernize their products but still some gaps for extreme diyers