Kemper SPDIF vs XLR

  • Hi,


    I've been using the Kemper for a couple years now. I love it live but my recorded tone has always sounded dull and muddy to me compared to the live tones I get. Like a blanket over my tone. I have been using spdif for some years now.

    I recently bought a Captor x to compare my KPA tones to my 6505+ tone. What I discovered was that the fidelity from Captor X was much better when compared to profiles similar to the 6505+ using XLR. So I decided to plug the KPA in using the same XLR cable and WOW what a difference.

    Like the blanket was removed!!


    My rig: KPA spdif into Focusrite 18i20 G2.

    KRK Rokit 5 G2 monitors.

    Mesa OS 412 for live.

    KPA kone for live.


    The spdif cable I use is an Amazon basics digital spdif.

    XLR is Monster Pro 900series.


    Could the quality of my spdif make that big of a difference? It's digital, why would that matter?


    Thanks for your suggestions.

  • I find the two similar enough that it makes no difference. I often use XLR. SPDIF is real convenient though.


    it sounds as though something is wrong with the input settings on your interface. Are you using combo XLR/TS inputs? Not sure about the 18i20 but these often automatically engage the Mic preamp when you us an XLR. In this case you are often better using a simple TS cable instead of XLR.

  • I find the two similar enough that it makes no difference. I often use XLR. SPDIF is real convenient though.


    it sounds as though something is wrong with the input settings on your interface. Are you using combo XLR/TS inputs? Not sure about the 18i20 but these often automatically engage the Mic preamp when you us an XLR. In this case you are often better using a simple TS cable instead of XLR.

    I will try the TS as you have stated and see if this has an impact. I love the sound I get using the XLR. But the sound with the Spdif is pale in comparison. I would have assumed it would be more polished than XLR or TS. I will experiment and see what results I get.

  • I'm having a similar problem. I'm using 2 solid quality SPDIF cables connecting into my Clarett 4 Pre interface. If I listen to my tones through the headphone jack of the Kemper, they sound amazing. If I then plug my headphones into the headphone jack of the interface, they sound like a blanket is over them. This is also how they sound if I record them and then play them back through my Yamaha HS8 speakers. I haven't tried XLR cables yet because I thought SPDIF was supposed to be the clearest connection.

  • I've heard some say that different SPDIF cables matter? I thought SPDIF was supposed to sound the same no matter what cables you use, they're just transmitting 0's and 1's right?

  • I ordered a Mogami Spdif cable with 75ohm. Once I receive it I'll report back on my results. The spdif is handy for reamping, but I guess I can find an alternative if spdif is a bust. I use high quality XLR and so it stands to reason that high quality spdif would be no different. The audiophiles who use spdif for their elite sound systems swear by their $500 spdif cables. I hope the new cable is a solution.

  • I'm having a similar problem. I'm using 2 solid quality SPDIF cables connecting into my Clarett 4 Pre interface. If I listen to my tones through the headphone jack of the Kemper, they sound amazing. If I then plug my headphones into the headphone jack of the interface, they sound like a blanket is over them. This is also how they sound if I record them and then play them back through my Yamaha HS8 speakers. I haven't tried XLR cables yet because I thought SPDIF was supposed to be the clearest connection.

    I have recognized this very same thing. It has baffled me for years.

  • I've heard some say that different SPDIF cables matter? I thought SPDIF was supposed to sound the same no matter what cables you use, they're just transmitting 0's and 1's right?

    basically yes. As long as the cable is suitable for transmitting those 0’s and 1’s. The problem is that some people use regular cheap RCA audio cables rather than Digital cables. i’m not an expert on it but the key point is that Digital cables have a 75ohm impedence.

  • Ok I'm back with some info. So I got a Mogami 2964 75 ohm digital coaxial s/pdif cable from Amazon.com. What I have found is:

    This cable made a very big difference in quality of sound from the previous Amazon basics digital coax. However, when compared to the analog signal from the Kemper to the Scarlett 18i20 using XLR the difference is still massive. I did side by side comparisons of the Digital 44.1khz vs XLR. I even did a Digital 48khz vs XLR. Where the 44.1 was still a bit blanketed, it was far less than the other cable used. The 48 had better resolution of course, but it was a tad sterile sounding compared to the XLR. It also had a mid bump, at least that was my perception.

    All in all, I prefer the XLR tone and definition much more than the s/pdif.


    Something I had not considered in my experiment was the quality of contacts within the Scarlett 18i20 itself. Again, one would assume 0 and 1 being equal, but this discovery has me questioning the overall quality of the digital in/out on any unit used in this way. Would an UA interface be any different? What about Mackie, Behringer or Presonus spdif in/out?


    Anyway, I found a solution and I hope this thread finds its way to others questioning their digital tones.


    Happy playing and recording!

  • Certainly an interesting result. Would you be able to show us a few recordings with either spdif cable? Maybe just leave the looper playing and change the spdif cable to show the difference?

    Kemper PowerRack |Kemper Stage| Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Adam A7X | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R7 | Fender Stratocaster HBS-1 Classic Relic Custom Shop | LTD EC-1000 Evertune | 1988 Desert Yellow JEM

  • I can do that!

    That would be very interesting. Thanks!

    Kemper PowerRack |Kemper Stage| Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Adam A7X | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R7 | Fender Stratocaster HBS-1 Classic Relic Custom Shop | LTD EC-1000 Evertune | 1988 Desert Yellow JEM

  • I'd like to hear those too. You noticed a big difference between SPDIF at 44.1 kHz and SPDIF at 48 kHz, and between the different SPDIF-qualified cables? That's surprising to me. BTW, are you setting the Kemper as your clock master?


    Are you using any EQ on the analog outputs?

  • Chances are high that the tonal differences in XLR vs. S/PDIF are caused by the (mic) preamp of the interface, see post of lightbox here. If you like what the preamp is doing EQ wise you may analyse it's frequency response by two recordings of e.g. a loop (one XLR, one S/PDIF) with a Match EQ.

  • According to the Focusrite manual the interface will automatically switch to mic sensitivity as soon as an XLR plug is detected at the input.

    This will create a level mismatch between a device like the Profiler that sends a line level signal from its XLR output and the interface.

    A XLR to TRS cable would be the optimum analog connection in such a case.

  • Chances are high that the tonal differences in XLR vs. S/PDIF are caused by the (mic) preamp of the interface, see post of lightbox here. If you like what the preamp is doing EQ wise you may analyse it's frequency response by two recordings of e.g. a loop (one XLR, one S/PDIF) with a Match EQ.

    It's probably not only EQ though.

    Kemper PowerRack |Kemper Stage| Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Adam A7X | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R7 | Fender Stratocaster HBS-1 Classic Relic Custom Shop | LTD EC-1000 Evertune | 1988 Desert Yellow JEM