Cracks with SPDIF recording

  • Hi,


    I've just finished to record a song using SPDIF with the the KPA. After I finished to record everything, I realized that many cracks appear on my recordings, which is really annoying for me to see, since I've spent a lot of time on these recordings and I'm very satisfied with what I played.

    Here is an extract in linked file. I had to compress it to high quality mp3 to upload it here but I can assure you that it sounds the same in wav.


    So my question is: Is there a way to save my recordings and to make these cracks disappear?

    I would really be pissed off if I had to record all my song all over again.

    I do have the DI tracks recorded, but I don't know if they will always make the cracks appear or not, using different software and hardware. I tried to reamp with it but cracks appear again...


    To anticipate some of your questions: Yes I have synced my audio interface with the SPIDF source, and both the Kemper, my DAW and my audio interface were clocked to 48 kHz.

    And my KPA software and Rig manager are updated to the newest versions.

  • So there is no way to save these takes?

    Does it mean that the Kemper's SPDIF connexion is useless and that it's impossible to record the DI track while recording the processed track?

  • I just wrote this in another thread here in the forum on "General Recording tips":

    I usually do it simply via SPDIF out of Kemper to SPDIF in on interface. Output for SPDIF set to Git/Stack so I have the dry signal and the Amp - but no effects from the Effects section. That dry signal has exactly the right level automatically for reamping unless you change anything in the path. Careful when sending it back to the Kemper (I do this via SPDIF again) because you easily can be trapped by your DAW to have level changes or effects put on it. Make sure the pure dry signal is being sent back.


    Whenever I want stereo effects from the Kemper I add analog outs from the Kemper to analog ins on my interface and leave the rest unchanged.


    So the SPDIF out is by no means useless. Vice versa. Let's see how to figure out what your problems are with those recordings. Just one note: If the cracks are really in the recorded tracks then there is almost no way to clean that up. Before you re-record you should make sure that the setup is proper and does not create any unwanted artefacts.

  • P.S.: Cracks could also come from an inappropriate buffer setting. How is your buffer and latency set up? Do you need to monitor yourself through the DAW or are you mixing the signals somewhere?

  • Thanks for your answer. There wasn't any effect on the KPA when I was recording this, not even any tweak or volume change on the profile. I used the git/stack output. The small extract I posted is not a reamp, it's the SPDIF stack recording.


    When I asked if it's useless, I meant: Is there a way to make it work? If it works, of course, it's a great thing, but if it makes cracks when recording, then it's useless.


    I didn't change the buffer size on Logic pro. I just clicked on the "Low latency mode" because if I didn't, I would get a huge and very audible latency. I did put a few plugins in my DAW but they were all deactived when recording.

    The monitoring comes from the interface. If I click on the monitoring button on Logic pro, then I get the 2 monitorings at once and it creates a horrible phasy tone.

    Edited 2 times, last by Xisale ().

  • I would get a huge and very audible latency.

    Okay, that finally answers my question how you monitor yourself. You do it through the DAW and not on any direct way. So, for this you probably have a quite low buffer set up as per your "Low latency mode". That might potentially be a problem. But would also be problem for recording via analog outs. Did you try that already? Different result? Just do a small test to see if the problem remains.

  • The latency is audible only once I have recorded. At the moment where I play, there is no audible latency.

    I have recorded many times with the analog out and there was no cracks. I'll try again today to be sure.

  • To anticipate some of your questions: Yes I have synced my audio interface with the SPIDF source, and both the Kemper, my DAW and my audio interface were clocked to 48 kHz.

    Which Kemper version? If Rack or Toaster please remember that the Kemper needs to be clock master, i.e. SPDIF clock in the interface & DAW needs to be set to external/Kemper.

  • I have the 7.2.2 version (last one available for download on the Kemper website).


    I have followed this tutorial to set my interface :

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    Here is a screenshot of what I did in linked file.

    Did I forget something?

  • Izotope RX7 software is excellent at removing noise and clicks but you'll have to fix them all by hand.


    You could just not worry about it because a lot of issues you hear when solo'd you don't hear at all once the full band is playing.


    I'm not sure why the analog audio outputs don't have the same options as the digital outputs. I've asked several times and never received an answer.

    Pretty sure I started a thread about this awhile ago. I now just use a DI box before going into the Kemper to be able to record the direct if I need to.


    I track in Logic with a 256k buffer when using lots of VI and 128k if it's audio tracks only. I don't use ANY latency inducing plugins until I'm mixing and I only use the Low Latency button if I need to retrack something toward the end of a mix, which I really try to avoid.


    I tried using the SPDIF and ended up having some really terrible ghost in the machine problems, sessions crashing, noise bursts, etc. All kinds of crap and I had a hell of a time tracking it down. As soon as I stopped using SPDIF with Kemper it all went away. The Kemper needing to be the master clock can be problematic depending on the interface you use and your rig. I'm using an RME UFX which is probably the most stable of all interfaces and is known for it's excellent drivers.


    Being a recording musician is a great way to build up your troubleshooting skills! Eliminating one thing at a time and narrowing in on the problem is the only thing you can do.

    These profiles go to 11!

  • To anticipate some of your questions: Yes I have synced my audio interface with the SPIDF source, and both the Kemper, my DAW and my audio interface were clocked to 48 kHz.

    And my KPA software and Rig manager are updated to the newest versions.

    Frist things first,
    -- what Interface do you use ?

    -- what DAW do you use ?

    Kemper has to be S/PDIF MASTER. So eg. Focusrite has to stupid for S/Dif Clock (not Internal)

    If you don't have a track that you can reamp,
    try to remove it with a plugin or manually search for "remove clicks and pops" on youtube

    Be the force with you ;)

  • Thanks for the advises!

    Actually, at this point, I would prefer to spend a few hour in fixing the cracks with Izotope RX7 (if it actually works) than recording everything all over again.

    I did my absolute best to record these tracks and I would really be pissed of if any click would be hearable on the final mix.


    I would still be very interested to hear what would the Kemper engineers would tell us about that. If there is a SPDIF on the Kemper, we are supposed to be able to use it, right?

  • Frist things first,
    -- what Interface do you use ?

    -- what DAW do you use ?

    Kemper has to be S/PDIF MASTER. So eg. Focusrite has to stupid for S/Dif Clock (not Internal)

    If you don't have a track that you can reamp,
    try to remove it with a plugin or manually search for "remove clicks and pops" on youtube

    Hi Yoda,

    I use a Scarlett Focusrite 6i6 interface and Logic Pro X.

    As you can see in the picture I posted above, I synced the Focusrite with SPDIF before recording. Is it enough to make the Kemper the master clock or am I missing something?


    I would still like to find a definitive solution for this. Even if I am willing do to all I can to save these tracks, I don't intend to do these kind of things everytime I record a guitar track.

  • I would still be very interested to hear what would the Kemper engineers would tell us about that. If there is a SPDIF on the Kemper, we are supposed to be able to use it, right?

    I haven't had any problems since I set up my Focusrite Scarlett 8i6 2nd Gen correctly and used a high quality cable.

    Be the force with you ;)

  • Hi Yoda,

    I use a Scarlett Focusrite 6i6 interface and Logic Pro X.

    As you can see in the picture I posted above, I synced the Focusrite with SPDIF before recording. Is it enough to make the Kemper the master clock or am I missing something?


    I would still like to find a definitive solution for this. Even if I am willing do to all I can to save these tracks, I don't intend to do these kind of things everytime I record a guitar track.

    Did you setup the Focusrite control correctly ?

    Be the force with you ;)

  • What about the buffersize DAW ?

    Maybe dropout clicks because off buffer under run or cpu overload ?
    Did you use a backing track with a lot of processor load while recording?


    Only a Idea ..

    Be the force with you ;)