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I'm currently trying out my Lab 90s with a couple of high-end streaming transports, one of which has no USB-Audio out so it has to be connected by S/PDIF.
I get no sound when I play 192/24 files through this transport but as soon as I downsample to 96/24 the music plays.
The Technical Sound Guide says that the Lab 90s can accept inputs of "up to 192kHz" via S/PDIF, but for its other inputs the phrase used is "up to and including xxkHz".
Does this mean 192kHz will or will not work via S/PDIF? Does @GeoffMartin have a definitive answer?
I can’t explain your sound/no sound issue, my friend, but as I read the technical sound guide, SPDIF can accept 192/24...
Currently: BeoLab 17, BeoLab 18, BeoSound Core, Beosound Level, Beosound A1 2nd Gen, BeoPlay S8 Connection Hub, Halo, Essence Remote
Previously: BeoSound 1 non-GVA
Yes, the Sound Guide says it will, though it uses the phrase "up to 192kHz" as opposed to "up to and including", which is used for the other inputs.
Oddly, I've discovered it will accept native 192/24 signals through S/PDIF from one of the streaming transports I'm trying out, but not the other, which requires the files to be downsampled to 96/24.
This could mean that one transport is really outputting at 192kHz and the other is merely claiming to, or alternatively that one transport plays nicely with the Lab 90s and the other doesn't.
I can't decide which.
Deleted.
MM
There is a tv - and there is a BV
As for S/PDIF generally spoken - if sender and receiver are both spec'd to work at 192/24, you can expect it to work.
Seems not to be the case with one of your streamers.
Yes, it's odd that it isn't working. The streamer in question is the dCS Network Bridge, in case anyone is thinking of trying one out with Lab 90s. I may try it again tomorrow with a different coax cable, though since 192/24 worked fine with the other streamer (Auralic Aries G2.1) I don't think the cable is to blame.
The only thing that makes me think it could be a quirk of the Lab 90s is the use of "up to…" and not "up to and including…" in the Technical Sound Guide, which seems to imply that S/PDIF will sometimes work at 192kHz and sometimes not.
Good catch, my friends. Very strange... the SPDIF blurb does say “up to 192” but, for example, USB Audio says “up to and including 192”.
This is a very subtle distinction and I’m not sure why it’s written this way. I’m certain it’s not intended to be misleading so there must be a technical reason, as opposed to a semantics reason, for this. Perhaps Geoff can opine, if he’d be so kind?
Hi,
I finally had time and access to devices to test this.
Firstly, the "up to" and "up to and including" are simply errors on my part... (no conspiracy theories, please...) The Coaxial S/PDIF input can play LPCM at all standard sampling rates up to AND INCLUDING 192 / 24. I know this because, as I type this, I'm listening to high resolution pink noise at 192 kHz / 24 bit sent to the Beolab 90's on S/PDIF from an RME UFX+ sound card. 192 kHz pink noise is the pinkest of pink noises... ;-)
Reminds me of the joke about a priest, a minister and a rabbit that walk into a bar, and the rabbit says "waitaminute.... I'm a typo...."
I'll add the "and including" to the next version of the TGS so this can calm things down.
As to why the dCS is not working, I have no idea. Whenever I can't get Device A to work with Device B, my first test is to connect it to Device C to find out if it works there. If Device A doesn't work with Devices B and C, then the location of the problem is probably not Device B (Always remember that the common element in all your failed relationships is you...) Of course, if one doesn't have a Device C with which one can test things, then there's no telling whether the problem is in Device A or Device B.
One important thing to remember is that SDIF is not the same as SPDIF (the dCS has both) - but this does not seem to be the issue, since the 192 native files are apparently working. It also appears from the thread that the Auralic is working at 192. So, if this is correct, and since "my" RME card works with the Beolab 90s at 192, I would say that there's something strange going on in the dCS... but I can only guess.
@politician: sorry it took a while to answer this. I just saw your email about it on the weekend, and I wasn't able to test this with the sound card until this morning.
Cheers
-geoff
Thanks for the detailed response, Geoff. I don't have a Device C I can include in the test, but since the Lab 90s can accept 192/24 via the Auralic and since I've tried the dCS with two different coax cables I'm presuming the fault isn't with the Lab 90s or the cable. It's either some quirk of the dCS (which seems quite a fussy piece of kit altogether – there's a long list of things it won't or can't do) or simply that it doesn't play nicely with Lab 90s.
politician: Thanks for the detailed response, Geoff. I don't have a Device C I can include in the test, but since the Lab 90s can accept 192/24 via the Auralic and since I've tried the dCS with two different coax cables I'm presuming the fault isn't with the Lab 90s or the cable. It's either some quirk of the dCS (which seems quite a fussy piece of kit altogether – there's a long list of things it won't or can't do) or simply that it doesn't play nicely with Lab 90s.
Agreed... but the question that's bugging me is: why not?...
Maybe I should see if the friends I had at dCS 25 years ago are still working there... and whether they still remember me (we weren't THAT close... )
cheers-geoff
Yes, it's puzzling me as well! I'm likely to have the dCS for the next few days, so if you do discover a workaround in that time I can try it out. I was tempted to ring dCS and ask whether they have an explanation, but since I'm unlikely to buy the Network Bridge (the Aries G2.1 is much more versatile, and offers more exciting sound, though I have a suspicion that the Network Bridge's rendering is more accurate to what's on the master tape), I don't want to waste their time.
I actually wonder if it's a bug... They say in their manual:
SPDIF digital output
The SPDIF output on an RCA connector (C) carries SPDIF data for output rates at 44.1, 48, 88.2, 96, 176.4 or 192kS/s or DSD/64 in DoP format, even if Dual AES mode is On. The maximum output rate is set by the Mosaic Control’s SETTINGS > DEVICE > SPDIF Downsampling section.
Here's my guess - but it's only a guess!
dCS invented the method of sending sampling rates higher than 192 called "Dual AES" mode (the AES/EBU prototcol is almost identical to S/PDIF. The only difference is that the "Copy Protect" flag bit is ignored in AES/EBU. Of course the voltages are different, but that's irrelevant to this discussion.) If I remember correctly, the trick is to send the Left channel on one AES/EBU cable and Right channel on the other, and re-assemble them at the receiving device. However, if they don't invoke the "invalid data" bit in the stream, a connected DAC would wind up playing only one channel in alternating samples at half the sampling rate (since, unless otherwise indicated, a DAC assumes that it's getting a valid signal at the rate of the data itself.... AES/EBU and therefore S/PDIF are based on a self-clocking bi-phase mark carrier).
So, if they forgot to disable the invalid data bit on the S/PDIF when running the AES/EBU at higher sampling rates, then this would cause a DAC to simply not play the signal.
You might want to check that Dual AES mode on the AES/EBU outputs is set to OFF - and that the AES/EBU is also set to a maximum sampling rate of 192 kHz.... If my guess is right, then this MIGHT cause the S/PDIF to work...
Just a shot in the dark - but it might be worth it.
Cheers-geoff
@Geoff Martin
I had a play around with the dCS – there's no option to enable or disable dual AES mode. All you can do is set the rate at which the device splits the AES feed, with a choice of 88.2, 176.4 or 352.8 kHz. I tried it all three ways and also tried toggling the other settings – such as enabling or disabling DSD downsampling – but with the same effect every time: music when S/PDIF is limited to 96 kHz and silence when set at up to 192 kHz. Obviously just some odd quirk of the Network Bridge!