Cambridge Audio CXN V2 DSD

Audio Gear Talk Cambridge Audio
22

I have the cxn. And agree that the cxn cannot decode dsd.
That we all agree.

I know that is I stream dsd to the cxn, it will not play. Periods.
Now if I stream using Dope, dsd over Ethernet works fine.

We all know how dop works.

Now
Question.
Is I stream dsd using dope protocol, can I output using coax dsd untouched.??
I ask because I can stream dsd using dope and output to my adi 2 dac fs.
The adi shows dsd 176 bits 24.
Is the cxn converting dsd over internet DOPE, to 176?
Or is the cxn outputing dsd within pcm.

I ask because spdifs should bypass any conversion.

Any one know?

23

The simple answer is no. It may well limit any pass through to 192khz too.

24

Henry.
I have been coax out from cxn to my adi 2 dac fs.
I did a test, I played a Dsf aka dsd. File on the cxn outputting to the adi. Now the adi 2 can play dsd over coax.
The adi will not allow dop using headphones, on adi

If I try to play dsd from computer… to adi using headphones it switches off direct dsd, and converts to pcm All fine there.

Now if I play a dsd file on cxn then out using coax to adi. The adi reports Cannot play direct dsd converting to pcm.

So the cxn must be sending dsd out of the coax?
The adi is detecting dsd over pcm.
Therefore the cxn isn’t converting to pcm. What’s your opinion?

25

I imagine it’s passing through as DoP and bypassing the internal DAC so no need to convert it to PCM as it would using its own DAC. . But it will be limited DoP as that’s the only way to get it via coax. DoP is still DSD encoded it’s just wrapped in a PCM wrapper for transport. The RME supports DoP and will see it as DSD and convert to pure PCM. Nothing seems odd here. Roon won’t know it’s being connected to an external DAC via coax though so might throw Roon a curve ball as it knows the CXN DAC can’t handle it.

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26

Hi Terry, the original DSD specification for spinning disks prohibited the passing of DSD over SPDiF/coax. It looks like that is relaxed when playing files. If that is the case then it does look as if the DAC is being bypassed or it is respecting the PCM envelope and leaving the DSD unchanged if DOP.

27

Yes. That’s what I think.
You see the adi 2 dac will except dsd 64 - 256 coax input dop format.

I always thought that cxn wouldn’t output dop on coax out.

But the adi 2 dac tells me dsd 176khz so it looks like cxn isn’t processing.

Thanks for your answer cheers.

28

That is sort of what I’d expect. It is telling you it is DSD(64) but that it is in a 176k PCM envelope. But normally a DAC doesn’t go into that detail. It has me wanting to play with a CXN v2 just to see for myself!

29

Henri.
I was told the cxn can. Only output 192 max coax.

It definitely passes the dsd as dop untouched.

I definitely think that it’s dop untouched.

For instance… the adi 2 dac turns dop off and converts dsd to pcm ONLY when using Headphones.

Xlr and rca are dop.

Now if I play dsd from cxn coax… and I turn on direct dsd on adi, adi dac say…cannot play dsd direct using headphone, Then switches to pcm.
So yep cxn passes dsd untouched coax out.
Brill.

30

henry…
iam a little late on updates but i have noticed dsd out on coax may not be dsd DOP.
I noticed on adi 2 dac read out that along with dsd also shows 24 bit…

DOP Shouldnt show 24bit.

seems to me that the cxn is converting dsd though coax out , and retaining DOP header, hence adi shows DSD . All very strange.

31

I can now confirm.

The cxn passes bit perfect from coax and optical. And usb.
I ran tests on adi 2 dac fs.
The test play files
44.100 16 bit
44100 24 bit
96 24 bit
All the way up to 192 kHz,

The adi shows if each file is bit perfect.
Either fails or displays test passed bit perfect.

The files played are special files.
I can play them from comp. or usb stick and drive attached to cxn.
All passed.
And it there was a any jitter or change in signal it would show failed.

So it puts all doubts to bed.
Outputs coax toslink from cxn are bitperfect

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32

Use external old DAC (PCM 63pk) by coax from CXN V2. The dsd64 files failed but wav, flacs are ok.
This might confirm coaxial only deliver DoP but not PCM.
Anyone knows how to change it?

34

I’m a bit confused here. I know Cxn upsamples everything to 384…but when playing a DSD64 file via Roon through the CXN to my Denafrips Ares II, the Ares shows that it’s playing a DSD track. Shouldn’t it show 384 due to the upsample?

This also happens whether streaming 44.1, 48 etc. always shows proper sample rate despite upsample.

35

As far as I know, the CXN only upsamples when it is being used as the DAC. If it is just passing the signal on, it is untouched.

36

Interesting.

Odd because i see the upsample in the Roon signal path. Wonder if ROON just assumes I’m using the internal DAC in the CXN?

37

That information is being sent to Roon by the CXN, so Roon is just showing what it is being told by the Cambridge.

38

The CXN does not switch between outputs, they run in parallel. The CXN behaves differently dependent on output but to be Roon Ready it is obliged to report what it would do via its analogue outputs. My view is its digital outputs can not be viewed as properly Roon Ready but I’ve no idea if the disparity is properly reported in any of the manuals. If you use the digital output you dispense with accurate reporting of what is happening in the signal chain.

39

So all outputs are “hot”

40

That is not what I been told by their support,which claimed
There’s non conversion when you use a usb stick

“Is the DSD file is translated to pcm before decoding to analog on the CXN - the answer here would be no.In this case,the CXN is just reading the DSD file from the drive and converting that signal to analog 2 channel stereo “

41

Well, unless there has been a change in their processing since 2020. See post above from Roon’s own product support.

42

Now I am more confused then ever,you are saying. Cambridge support don’t even know their own product?