Native DSD in DSD playback strategy

Audio Gear Talk Raspberry Pi
21

@spockfish yes I have a the usb dac we discussed connected on the RPi

22

I have pressed the feedback button with UiD f01446ab9916a199 if thatā€™s of any help
Thanks

23

Ok. I already see the problem. it failed to download Roon Bridge because it had no connection during install.

I suggest you do a retryā€¦

24

@spockfish Hi Harry,

Please can you work some magic with the Matrix X-SPDIF 2? :slight_smile:

[root@ropieee ~]# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: X2 [X-SPDIF 2], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

[root@ropieee ~]# cat /proc/asound/card*/stream*
Matrix Audio X-SPDIF 2 at usb-3f980000.usb-1.4.1, high speed : USB Audio

Playback:
  Status: Stop
  Interface 1
    Altset 1
    Format: S32_LE
    Channels: 2
    Endpoint: 1 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000, 705600, 768000
    Data packet interval: 125 us
  Interface 1
    Altset 2
    Format: SPECIAL
    Channels: 2
    Endpoint: 1 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000, 705600, 768000
    Data packet interval: 125 us
  Interface 1
    Altset 3
    Format: S32_LE
    Channels: 2
    Endpoint: 1 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000, 705600, 768000
    Data packet interval: 125 us

[root@ropieee ~]# lsusb
Bus 001 Device 012: ID 20b1:2004 XMOS Ltd 
Bus 001 Device 011: ID 1a40:0101 Terminus Technology Inc. Hub
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
25

Iā€™d love to, but you need something from your DAC supplier.

To be able to do native DSD the kernel needs to be patched, but this output above should mention at least an Altset with a Format that looks like this:

Format: SPECIAL DSD_U32_BE

As this is a DAC equipped with the Xmos set you maybe should ask for the lastest firmware. Whatā€™s even weirder though is that Maxtrix has other DACā€™s that are supportedā€¦

26

Now, the interesting thing is that this is the second XMos DAC that annouces an altset like this, without the DSD identifier.

I need to see if I can get in contact with those guys to ask whatā€™s going onā€¦

27

Appreciated. I asked Matrix about DSD support:

has this deviceā€™s USB ID been added into the Linux kernelā€™s list of native DSD capable devices?

and got the reply

X-SPDIF2 USB ID has been added into the main stream Linux kernel, such as ubuntu

Not sure what that means TBH.

28

I do know what the mean.

The first question is ā€˜noā€™, but thatā€™s something I can do.
And their second reply says ā€œhe, our previous DACā€™s have been added so this should workā€.

So you have a RoPieee lying around? What I can do is build a new kernel (even with this notation) and we can just see what happens.

29

WEll, on second hand, their second response is weird.

ā€œmain stream Linux kernel, such as Ubuntuā€.

Thatā€™s justā€¦ a strange answer. There is nothing as ā€˜main stream Linuxā€™. What he just means is that the USB ID itself is added to the USB ID table, but thatā€™s totally not important (itā€™s just a translation from ID to string).

Anyways, I would say: letā€™s build us a kernel and test.

1 Like
30

I guess it was a not 100% fully informed answer from a support person, not a dev.

31

Ok. Couldnā€™t help myself, so I started a kernel build. Will take until tomorrow though.

If you got a RoPieee lying around we can do some testing tomorrow.

1 Like
32

Morninā€™ @joel,

Iā€™ve got a new kernel for RoPieee lying around to test this DAC.
So let me know if you want to test this.

Regards,

33

Sure! What do I do?

34

Get a RoPieee up and running, preferably a beta one: http://image.ropieee.org/ropieee-beta-20170816.img

Then Iā€™ll push the new kernel to the update channel and you can test.

35

I have a normal one (I think) up and running. Is there any way to switch channels or do I need to re-install?

36

@joel Oh cool. Then you can switch channels on the ā€˜advancedā€™ tab of the web interface.

37

Okay, I switched channels and rebooted. Currently Iā€™m showing:

Screen Shot 2017-08-30 at 11.12.03.png815Ɨ198 9.92 KB

38

Ok. Now you need to wait for the update (will take 15 minutes), because the kernel should say ā€˜4.9.32-2ā€™.

39

Well it now shows 4.9.43-2, which seems to make more sense as itā€™s a higher version than I had before. Did you mean 4.9.32-3?

40

no youā€™re right. :slight_smile:

ok. now it needs one more reboot.