DSD USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN

Technical discussions related to any XMOS development kit or reference design. Eg XK-1A, sliceKIT, etc.
Guho
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DSD USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN

Post by Guho »

Hi there,

Is the USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN compatible with native DSD or/and DoP?

At the description ( http://www.xmos.com/en/products/referen ... ltichannel ) I can't find any information about DSD.
But at "Documentation and downloads" > USB Audio Class 2.0 Driver for Windows Overview (USB-Audio-2.0-Driver-for-Windows---Overview(2.0).pdf ) I read that the multichannel reference design board is fully compatible with native DSD and DoP: https://www.xmos.com/en/download/public ... 2.0%29.pdf

If this is correct then all other information that I find under the "Documentation and downloads" of the Multichannel reference design seems to be outdated.

Are the new MULTICHANNEL REFERENCE PCB's shipped with a new, DSD compatible, firmware?
Is there any documentation available about multichannel reference design DSD support?
Or will the MULTICHANNEL REFERENCE DESIGN be updated with DSD compatibility in the near future? Is there something that I am missing?

I saw the MFA board, but my goal is to build an multichannel DAC with DSD support. MFA only supports stereo, from what I can understand.

Any information about this subject is welcome and will be much appreciated!


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Ross
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Post by Ross »

Guho wrote:Hi there,

Is the USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN compatible with native DSD or/and DoP?
No, its isn't. Sadly the CODEC on that board does not support DSD.

The reference design software does support DoP and a Native DSD implimentation. However, the only XMOS hardware that can support DSD is the "MFA" board (part no xk-usb-audio-u8-2c), but as you say this is stereo only.

The code can of course run on a custom multi-channel hardware with DSD support...

Are you wanting multi-channel PCM with stereo DSD or multi-channel DSD?
Guho
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Post by Guho »

Thank you for the quick reply Ross.

With the CODEC you meant only the DAC chip, so the XMOS chip itself(XS1-L16-128) - and the multichannel reference design board - is compatible with DSD? If this is the case then this won't be a problem because we use an external DAC-board; so we will tap the i2s / DSD lines.

Our goal is to support multichannel PCM and DSD. What is necessary for multichannel DSD support? Do we need to write custom code for this?

Is the MFA firmware usable for the multichannel reference design board (and with the XS1-L16-128) with minor customizations?

The current "XMOS USB Audio 2.0 Reference Design" has "Supported options" for "DSD_CHANS_DAC": 0 or 2. From what I understand this means stereo only.

Is multichannel DSD for the "XMOS USB Audio 2.0 Reference Design" in development? And is there a new MFA board with Multichannel DSD in development? Since the name is xk-usb-audio-u8-2c, 2c suggest 2 channels and the board has just been released.

Thank you again for your cooperation. We're looking forward to your reply.
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Ross
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Post by Ross »

Guho wrote:Thank you for the quick reply Ross.

With the CODEC you meant only the DAC chip, so the XMOS chip itself(XS1-L16-128) - and the multichannel reference design board - is compatible with DSD? If this is the case then this won't be a problem because we use an external DAC-board; so we will tap the i2s / DSD lines.
Yes, by CODEC I mean an external device - that board has a Cirrus Logic CS42448 multi-channel CODEC connected to the L16 via I2S. The CS43448 doesn't support DSD.
Guho wrote: Our goal is to support multichannel PCM and DSD. What is necessary for multichannel DSD support? Do we need to write custom code for this?

Is the MFA firmware usable for the multichannel reference design board (and with the XS1-L16-128) with minor customizations?

The current "XMOS USB Audio 2.0 Reference Design" has "Supported options" for "DSD_CHANS_DAC": 0 or 2. From what I understand this means stereo only.
You are correct, the current reference design firmware assumes stereo only for DSD (no matter how many I2S channels).
Guho wrote: Is multichannel DSD for the "XMOS USB Audio 2.0 Reference Design" in development? And is there a new MFA board with Multichannel DSD in development? Since the name is xk-usb-audio-u8-2c, 2c suggest 2 channels and the board has just been released.

Thank you again for your cooperation. We're looking forward to your reply.
We haven't seen much demand for multi-channel DSD, having said that it should not take much to modify the code for this - I will investigate.
Guho
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Post by Guho »

Thank you for the clear information Ross.

The demand is out there, the market for multichannel DSD is relatively fresh but is growing fast. Big brands like Oppo and Sony make multichannel DSD DAC’s. And Exasound, for example, is a multichannel DSD specialized company which only sells multichannel DSD DAC's.

Multichannel DSD is - for audio applications - really the only thing that XMOS is lacking at this moment.

For our project multichannel DSD support is a must, so if this can be achieved with XMOS, then we will go ahead with XMOS. The support, the flexibility and the open-source approach of XMOS is great.

Please keep this thread updated with your findings, I’m looking forward to the result of your investigation. Thanks a lot !
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Ross
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Post by Ross »

Guho wrote:Thank you for the clear information Ross.

The demand is out there, the market for multichannel DSD is relatively fresh but is growing fast. Big brands like Oppo and Sony make multichannel DSD DAC’s. And Exasound, for example, is a multichannel DSD specialized company which only sells multichannel DSD DAC's.

Multichannel DSD is - for audio applications - really the only thing that XMOS is lacking at this moment.

For our project multichannel DSD support is a must, so if this can be achieved with XMOS, then we will go ahead with XMOS. The support, the flexibility and the open-source approach of XMOS is great.

Please keep this thread updated with your findings, I’m looking forward to the result of your investigation. Thanks a lot !
We are currently working on a multi-channel solution based around the xCORE USB sliceKIT (https://www.xmos.com/products/xkits/slicekit) which could potentially provide this feature.

I will try and keep this thread updated.
Guho
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Post by Guho »

That is great news Ross! We're looking forward to the development.

Will the new slice have I2S/ DSD output by header pins? So that the developer could connect the slice to their own CODEC / DAC ? I am sorry to ask you this in such an early stage of development; but do you have any ETA for this solution? I need to ask you this because we are working on a tight time schedule.

Will the multi-channel solution support 6 or 8 channels?

Would it be possible to start our development now with the USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN together with our own DSD CODEC. And use the audio source code of the MFA to add stereo DSD support to the USB AUDIO 2.0 MULTICHANNEL REFERENCE now? And add the the new multi-channel DSD firmware; when the development is done?

Thank you for your cooperation!
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Ross
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Post by Ross »

Guho wrote:That is great news Ross! We're looking forward to the development.
Will the new slice have I2S/ DSD output by header pins? So that the developer could connect the slice to their own CODEC / DAC ?
Yes, all DSD/I2S lines would be on test points (like the L16 design).
Guho wrote: I am sorry to ask you this in such an early stage of development; but do you have any ETA for this solution? I need to ask you this because we are working on a tight time schedule.

Will the multi-channel solution support 6 or 8 channels?
As I say, it's under-deverlopment. But it is likely that we would stick with a similar channel count to our L16 design (so 8 plus digital interfaces)
Guho wrote: Would it be possible to start our development now with the USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN together with our own DSD CODEC. And use the audio source code of the MFA to add stereo DSD support to the USB AUDIO 2.0 MULTICHANNEL REFERENCE now? And add the the new multi-channel DSD firmware; when the development is done?

Thank you for your cooperation!
The source code for the L16 (USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN) and MFA designs are 99% shared - with extensions for board support (DAC setup etc) and config defines for channel count, feature enabled etc.

So yes, you could start with either of these designs and add multi-channel at a later point via firmware upgrade.
Guho
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Post by Guho »

Thank you for the clear reply Ross. That is really great to hear!

We will start our development with the USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN and add the multi-channel DSD in a later stage; when the firmware update / source code is available. Thanks again!
Guho
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Post by Guho »

Ross wrote:
Guho wrote:That is great news Ross! We're looking forward to the development.
Will the new slice have I2S/ DSD output by header pins? So that the developer could connect the slice to their own CODEC / DAC ?
Yes, all DSD/I2S lines would be on test points (like the L16 design).
Guho wrote: I am sorry to ask you this in such an early stage of development; but do you have any ETA for this solution? I need to ask you this because we are working on a tight time schedule.

Will the multi-channel solution support 6 or 8 channels?
As I say, it's under-deverlopment. But it is likely that we would stick with a similar channel count to our L16 design (so 8 plus digital interfaces)
Guho wrote: Would it be possible to start our development now with the USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN together with our own DSD CODEC. And use the audio source code of the MFA to add stereo DSD support to the USB AUDIO 2.0 MULTICHANNEL REFERENCE now? And add the the new multi-channel DSD firmware; when the development is done?

Thank you for your cooperation!
The source code for the L16 (USB AUDIO 2.0 MULTICHANNEL REFERENCE DESIGN) and MFA designs are 99% shared - with extensions for board support (DAC setup etc) and config defines for channel count, feature enabled etc.

So yes, you could start with either of these designs and add multi-channel at a later point via firmware upgrade.
Hi Ross,

How is the development going?

8 months have passed since you informed me about the development of the multichannel DSD addon for the xCORE USB sliceKIT (https://www.xmos.com/products/xkits/slicekit).

When will the new "slice" for multichannel DSD be released? I would like to buy this board ASAP.

I'm looking forward to your reply!

Kind regards