Changes to sound while playing

    I have a problem that I can't solve. When my Kemper is working right, it sounds awesome. However, once about every 10 minutes the sound changes from a nice thick tone to a more thin tone with more icepick highs. The crazy thing is that almost anything I do like switching patches, or pulling out my guitar cord and putting it back in, or pulling out the midi cable and putting it back in, etc. fixes the problem. Then it plays fine for awhile but pretty soon, I have the same problem again. I have changed out all of my chords, tried different guitars, bypassed my pedal board, and still this continues. The last operating system upgrade seemed to help a little but didn't completely get rid of it. I have been looking for the answer outside of the Kemper up until now but I talked to a tech at Sweetwater the other day and he said that he had a similar problem with his Kemper and suggested that I post here to find out if others are having that same problem. Any suggestions on a permanent fix will be greatly appreciated.
    Thanks

    This is very interesting. During rehearsal, which last about two hours, there are several moments when I notice the same thing. Originally, I was just assuming it was ear fatigue, but now you have me curious. It would be interesting to hear if anyone from Kemper responds.

    “When the power of love overcomes the love of power the world will know peace.”

    Never had this problen - in 3 years and two Kempers.


    Please try with a naked Kemper - connect just the guitar and headphones - then play and wait if it happens again - if you got the same problem again call support.

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    Great Profiles --> soundside.de

    Thanks for the responses! I also have 2 Kempers and both of them do this. I will try the suggestions and see what happens and then report back here as soon as I have any more information.

    Quote from Raoul23

    Oh boy!!!! Both of them do it??? I can't believe you have 2 faulty ones it must be something else other than the KPA :)


    Yeah, operating the Profiler alone seems the first necessary troubleshooting step. Do not bypass things, just disconnect them


    Also, how are you listening to it?

    Still haven't had time to detach everything and run just the Kemper and headphone but here is a list of what I use in the signal chain that might help trouble shoot this problem.
    I run 2 Kempers into an EV ZLX-12P. The signal chain goes Guitar--Buddy Guy Wah--Boss DS-1--Xotic RC Booster--Visual Sound Liquid Chorus--Radial JX2 Switchbone-----this splits into 2 outputs so one goes to each of the Kempers.-each Kemper monitor out goes to one of the 2 inputs on the EV ZLX-12P.
    Both of the Kempers are always on and I blend the amp profiles together to make one sound like having 2 amps on at the same time.
    Also have an Art X-15 ultrafoot controlling the midi switching on both Kempers

    @flotto....The last firmware before the 2.5


    OK, I spent a few hours today playing each unit individually with everything disconnected except for the guitar and headphones.
    You guys were right, I could not get either unit to duplicate the problem that I have been having.
    Next I connected the midi controller back up and still couldn't duplicate the problem. So now I am still stumped but also excited that the units are not the problem.
    I have a feeling that either the Radial Switchbone or the Liquid Chorus may be the problem because they both have buffers and the Radial has switch options for the second output for a ground lift (which I have ON) and also for polarity either 0 or 180 degrees. (That is set to 0)


    I can't really eliminate the switcher box because that is how I split the signal to run to the 2 channel mixer in the powered speaker but I am up for suggestions. How would you proceed with the next level of troubleshooting?

    Never had this in 2 years, BUT ....


    ... recently I have had some intermittent, strange noises coming from the Kemper after moving to a different location.


    As it turns out it went away completely after pressing the little Ground / Lift button next to the output section on the back.


    Might be worth trying.


    Cheers,
    Martin

    Quote from giletti

    As it turns out it went away completely after pressing the little Ground / Lift button next to the output section on the back.


    Those Ground breaker buttons are life saving feature, especially for us, who do run only small home studio, where KPA is the most expensive equipment and where we don't have access to any external ground breakers.
    Thank you CK for this!

    Quote from tony11122


    I can't really eliminate the switcher box because that is how I split the signal to run to the 2 channel mixer in the powered speaker but I am up for suggestions. How would you proceed with the next level of troubleshooting?


    By adding one unit at a time.


    If the switcheris not used for alternating between the two units, why don't you use a simple Y cable?


    Anyway, slightly OT, be sure your Profilers work with a fixed latency (see System Menu, IIRC). They will sound better, by alligning the phase of the two sounds.


    :)


    Yes exactly. By now I believe these are phasing issues like I wrote earlier.
    Try the 2 Kempers together.
    As soon as the issue occurring switch to fixed latency.
    It should be gone then and not re-occur.

    Quote from tony11122

    Not sure where to go to switch to fixed latency? Got to check the manual as viabcroce suggested and read up on this. Ingolf, should I leave the ground lifts alone?


    Ground lifts can be tried but I don't think a ground loop is the problem.
    The fixed latency switch is in the system menu, one of the pages 7 or 8 I think, try its soft knob.