SPDIF clicks

  • Hi I just got a RME UC and tried connecting my Ti Desktop through the SPDIF but I get clicks under some conditions so had to switch to analog ins. I brought this up at KvR and other users confirmed they also have this problem (and with different interfaces) - here is a test case I can replicate:


    Quote

    Select INIT patch, OSC balance to OSC 1 , Filter 1 to HP now play a high pitch note: say C7 ... turn the resonance up say to 127, and you can 'tune' in the cutoff to hear the clicking (around 80) if you play a different note, you can tune it using the cutoff/resonance


    This seems to happen when the Ti is slaved to the RME, if I make it master and set the RME to slave the clicks go away but that negates the whole point of using the RME as master as it also sets the midi clock for everything else on my system and without that the Ti is out of sync. One reason I went for RME is its strong reputation for this sort of thing.

  • Ive tried this test case, and get exactly the same error.
    Im using a TI keyboard mk1, with a Focusrite Sappire Pro 14.


    (important note: with exactly the same patch, if you route it via the analogue outputs, I do not get the click so it is not a function of the patch/filter etc)


    > RME as master as it also sets the midi clock
    I assume you mean, for the midi message timestamp (rather than the midi clock msg), and yes that true, and very important to use a stable clock source for, and Id prefer to use the Pro14 for the same reason.
    (that and often my TI is not within the setup, and i don't want to have to continually reconfigure this)

  • My UC shows that the Virus keeps losing clock sync -- the SPDIF light flashes every few seconds. I believe the Virus to be the problem, as it doesn't slave correctly to incoming SPDIF at present. Makes it difficult to use the digital input if it won't play nice with the rest of the setup's slave-clocked gear!

  • Select INIT patch, OSC balance to OSC 1 , Filter 1 to HP now play a high pitch note: say C7 ... turn the resonance up say to 127, and you can 'tune' in the cutoff to hear the clicking (around 80) if you play a different note, you can tune it using the cutoff/resonance


    does the problem persist if you lower the volume of the patch? i think it just clicks because it is to loud due to the maximum resonance. also, i don't understand why you need special patch to uncover a SPDIF related problem. if you use a pure sine wave on a low volume, you would hear much more, in case there is something to hear.
    marc

  • > if you use a pure sine wave on a low volume, you would hear much more, in case there is something to hear
    yes you can hear it using a sine wave on osc1, no effects/filter etc... its just a bit harder to hear, and yes its present at low volumes (its not clipping)


    perhaps worth saying... I originally notice this on a normal factory patch, in normal play (I think E-Grand HS)... obviously it was quite subtle,
    but very annoying (and not something you could record/release!), so i then tried to reproduce it, and make it more pronouced,
    so that Access support could reproduce and hear it, and then of course 'eliminate other possible causes'


    and why I assign it to a SPDIF sync issue? because even account for output levels (i.e. matching them) , with exactly the same patches, I don't get this when using USB output and I don't get it when using analogue outputs, and also if I change the Virus to SPDIF master again the same patch is also absolutely fine.


    there have been other reports of this in the past, and here amused and I, are reporting exactly the same issue... despite completely different hardware.


    Were you able to reproduce the clicking using SPDIF, where the virus is the spdif slave? (and you don't do any resampling of the input on your audio interface)
    (your words, "I think it just clicks..." seems to imply not, it implies a logical thought process instead of testing it)


    please, I know, lots of issues are reported that are due to user error, but surely given we have gone to the effort of a reproducible test case, have multiple users reporting,
    ... does this not warrant Access spending a few minutes to see if there is a slight chance there may be an issue?


    you may be right, it may have nothing to do with the spdif... (though I hope you can see why i think it is, due to details above),
    if you test it, I'm sure you will then be able to prove this one way or another, and enlighten us, to how we can prevent the issue arising with spdif, and start using it.


    does this sound like a reasonable way for us to work together to find a solution?

  • Were you able to reproduce the clicking using SPDIF, where the virus is the spdif slave? (and you don't do any resampling of the input on your audio interface)


    slaving the virus _and_ using it in a loop back situation only works for me if i resample at the input. i doubt that i can work another way. if i loop in a lexicon pcm90 for instance, i have to do the same.
    marc

  • yeah, I remembered being told in the loopback scenario i would need to resample. (ie. spdif in -> vir -> spdif out ) e.g. for digital fx loop.


    but this is not in loopback, this is soley, spdif output (no spdif audio input) from the virus with the virus using the spdif clock from the audio interface (which obviously comes over spdif input)


    are you saying the virus can never use an spdif clock input source, it has to use its own clock?


    what i find, odd about this, is when I use USB (which is digital like spdif), the virus is slaved to the host clock, which in my case is also provided by the same audio interface…. (this also works for audio loopback) , so it would appear the virus is quite capable of slaving to an external clock, just not via spdif.

  • are you saying the virus can never use an spdif clock input source, it has to use its own clock?


    if you setup something like master --> Virus (slave) --> another slave device there is no technical reason why it should not work.


    what i find, odd about this, is when I use USB (which is digital like spdif), the virus is slaved to the host clock, which in my case is also provided by the same audio interface…. (this also works for audio loopback) , so it would appear the virus is quite capable of slaving to an external clock, just not via spdif.


    no, this is two different scenarios (from a technical point of view).
    marc

  • if you setup something like master --> Virus (slave) --> another slave device there is no technical reason why it should not work.


    ok, this is complicating matters, simply the issue we have is
    audio Interface (master) --clock over spdif --> Virus (slave) -> audio output over spdif -> (same) audio interface


    with this, we are getting clicking at higher frequency notes, even with a simple sine wave...
    clicking that does not occur, with analog outputs or usb output, and we are not clipping the signal.


    so why the clicks?


    its not just, should it technically/theoretically work... the question is does it work for you?
    (again, assuming you don't resample, which negates the use of the audio clock)

  • sorry, my misunderstanding then ….


    my understanding was you said it could not be used as an fx loop
    i.e. audio interface(master) -> audio/clock -> virus (slave,spdif) -> audio -> audio interface.


    where as now I'm understanding, you meant it more generally:
    you cannot have the virus using a slaved spdif clock, if you are going to send the audio output back over spdif
    (without resampling the audio, but if you do this, there is no point in sending a clock in the first place… no?)
    is this correct?


    so when is it useful to have the virus use an external spdif clock input?
    (my assumption, and please correct, me as it appears they usually are wrong!)
    is that its only useful to use the spdif clock slaved if you are sending an audio signal as input over spdif
    AND then are either:
    i) sending the output via analogue outputs
    ii) sending the output via spdif, but resampling the output on the audio interface.
    correct?


    sorry, if this is all very clear to you, but i think others like me, just assume you plug the 2 spdif cables in, set it to slave, and it just works… so its useful for us to know this is not the case, and what the correct usage is.
    thanks for your patience :)


  • sorry, if this is all very clear to you, but i think others like me, just assume you plug the 2 spdif cables in, set it to slave, and it just works… so its useful for us to know this is not the case, and what the correct usage is.
    thanks for your patience :)


    Yeah, sadly the Virus doesn't appear to clock properly to SPDIF input, making it impossible to integrate this into a digital studio running off a central clock, without clicks and pops occurring.


    Do you by any chance also get the "Clock problem at SPDIF Input" message when trying to config the audio clock?

  • <p>I'll chime in here too, I've had SPDIF working on the past but that was a long time ago with a different Virus OS and computer. I'm unable to get it working properly now, like others I'm getting clicks in the audio along with a &quot;Clock problem at SPDIF input&quot;</p>


    <p>This happens if I have both the Virus SPDIF In and Out connected to my audio interface.</p>


    <p>I don't see the clock problem message if I only have the Virus SPDIF output connected to my audio interface SPDIF input and have the Virus audio clock set to Internal and the interface sync source set to SPDIF, however I still experience audio clicks.</p>


    <p>I am using a Focusrite Saffire Pro 40 and I beleive I have followed these setup instructions to the letter, but I must be doing something wrong as I am still experiencing these issues.</p>


    <p>&nbsp;</p>


    <p><a href="http://uk.focusrite.com/answerbase/how-do-i-use-the-spdif-inputs-and-outputs-on-the-saffire-or-scarlett">http://uk.focusrite.com/answer…n-the-saffire-or-scarlett</a></p>


    <p>&nbsp;</p>


    <p>Any advice on correct set up would be greatly appreciated.</p>


    <p>&nbsp;</p>


    <p>Thanks</p>

  • does the problem persist if you lower the volume of the patch? i think it just clicks because it is to loud due to the maximum resonance. also, i don't understand why you need special patch to uncover a SPDIF related problem. if you use a pure sine wave on a low volume, you would hear much more, in case there is something to hear.
    marc


    Yes, it has nothing to do with the volume because I do not get it at the same volume when the Ti is master, or with the same setup using the analog outs.

  • ]
    Yeah, sadly the Virus doesn't appear to clock properly to SPDIF input, making it impossible to integrate this into a digital studio running off a central clock, without clicks and pops occurring.


    Do you by any chance also get the "Clock problem at SPDIF Input" message when trying to config the audio clock?


    Yes, I think if i insert the spdif in cable after I've turned the virus on (tbh, i can't remember exact situation)
    I did try to troubleshoot this with Access, but they just blamed the audio interface, cables and then finally my TI. when I highlighted that multiple threads on the forum, showed others had the same issues with different Tis and different audio interfaces. they still insisted it was TI hardware issue and I should send my unit to germany for repair.
    Realistically, every one that posts here, seems to have problem with the spdif clock, so there was no way I was going to go to the expense of shipping and repair, and risk of transport damage and be weeks without my TI, only to have my TI shipped back with the repair shop to say they cannot find any issue!
    (after which i still very much doubt Access would acknowledge the problem, they would just blame my audio interface… Id then buy another one, same issue, and so the saga would continue.)
    At that point I gave up with spdif on the virus… figuring it doesn't work properly and it never will.


    p.s. Sorry, Marc, if this comes across as negative, i truly respect the work the support team does, and clearly you help a lot of people with issues, which are due to their setups. I also think Access really has done a great job at supporting products that were released many years ago.
    but the whole spdif saga is really irksome, it truly feels like the devs have no interest into really digging into these issues, doing some proper testing… and find it easier to just say its a user issue, or hardware issue, or its the other audio interface - or any other excuse, which means they do not have to test it.
    (perhaps its part of ploytec code, so outside direct access control?)

  • let me just write a short and final comment on SPDIF.
    the format was never the easiest in terms of sync and also in product compatibility. the main reason for the clocking problems some experience is, that there is no consistent and independent master clock available. the clock is a part of the data stream and that in itself can cause loads of problems. but we have not developed SPDIF, we are just using what the hardware chip in the Virus provides. we have not developed this chip either, btw. the other issue is, that there are multiple variations of SPDIF and those are not necessarily compatible. my comments above illustrate the only, relatively save way to avoid clocking issues but all that will only work, if the individual SPDIF components of the equipment used will be 100% compatible as well.
    best, marc