Alternative input hiss.

  • Hi! It's my first post, so hello to everyone. I have got an issue with my Kemper Amp. I'm using a wireless system live and I noticed, that when I plug the unit via Jack-Jack cable to the Alternative Input it is realy noisy. But when i plug it (the same signal chain) to any other input it's way quieter (Front/Return). It can be eliminated by Noise Gate on the front, but i have to turn it to values like 6.0 and more and using is too noticeable for me. It's not a problem with my wireless, because when I plug my guitar directly, using a cable, the problem is still present at Alt.Input and disappears at the others. Is my Profiler broken? Best Regards

  • Kemper has indicated the signal to noise ratio is lower for that input than for the front input, and is best suited to low gain sounds - it is in the software Release Notes. None of us would be able to tell you if your particular Kemper has a noisier Alt input than the rest of them without having two Kempers together.


    But, If that input is too noisy for your wireless, use the front input:)

  • What's the noise like? Hiss, or buzz? Did you try switching the ground lift?


    I'm wondering....the Alternative input can be used as one channel of a stereo aux config. Is there an Aux level you may need to turn down in the Output menu? From the manual: "Please do not forget to turn down Auxiliary Input when you are not using it, to prevent unwanted hum and noise being added to your amp signal."


    Kemper has indicated the signal to noise ratio is lower for that input than for the front input, and is best suited to low gain sounds - it is in the software Release Notes.


    Software release notes on hardware specifications? :) The manual indicates that the front input has the greatest s/n ratio. >108dB compared to 105dB for the others.

  • Thanks for responses.

    Quote

    "The manual indicates that the front input has the greatest s/n ratio. >108dB compared to 105dB for the others."

    The noise disappears when I plug it for example to the return input. So other than the front input and quiet. :) But I think, that the difference shouldn't be that big.


    Quote

    "What's the noise like? Hiss, or buzz? Did you try switching the ground lift?"

    It's a hiss. I'll record an audio in a moment.



  • Did you check the Aux In levels in the Output section? They should be at zero.


    EDIT: Nah, that didn't make any difference.


    I just checked the inputs myself, without connecting anything. Yes, there is more hiss when the Alternative input is chosen.

  • Noise Recording
    Guitar Vol is all the time at 0. It is recorded at a high gain profile. I'd understand that noise if at the return it was the same, but it's not. :) Then if I plug a stereo unit in effects loop then one side will be noisier than the other one.


    And the return input seems to be the quietest. Weird.

  • From the Profiler Addendum Manual 2.1, page 6:
    QUOTE:
    When Input
    Source is set to Alternative Input, the Alternative Input won’t work as long as a cable is connected to the front Input.

    The Alternative Input on the rear panel can now be used in rack mounted setups, however is more noisy than the front instrument Input.


    END OF QUOTE



    I think the return can't be used as Instrument input.

  • It can be used as input. I'm preety sure. I'll check that when i get back home, but i think so. But is it normal that the noise amount goes like alternative input>front input>return input? Shouldn't it go like return input=alternative input>front input? Could You please check that on Your KPA in the same way as i did? Is it the same or i should be worried?

  • The Return can not be used as an INSTRUMENT input, i just gave it a try to be sure. It is available as an auxiliary input, you may use it as an FX return in a loop stomp or as input for an external device such as an mp3 player. As the audio signal you feed into the Profiler is not being processed (if you plug your guitar in here you only get a clean, DI-like tone) it is less noisy in your test.

  • It can be used as input. I'm preety sure. I'll check that when i get back home, but i think so. But is it normal that the noise amount goes like alternative input>front input>return input? Shouldn't it go like return input=alternative input>front input? Could You please check that on Your KPA in the same way as i did? Is it the same or i should be worried?


    In what way are you using the return input? Activating a loop in slot A-D, and listening to the resulting noise? I'm thinking the return and aux inputs are the same, but of different sensitivity when used as guitar input/loop input (...just thinking out loud, without coffee 8) ). If you're using a clean amp, is the guitar level the same when using the return/aux inputs?

  • Check out that second video. At first guitar is plugged in the front input, normal sound. Then I plug it to the return input, set that input in input section (return reamp) and i get processed sound. Later i show you that no loop is activated. Just simple JVM preset downloaded from the site.
    Kemper Return Input processing

    Quote

    If you're using a clean amp, is the guitar level the same when using the return/aux inputs?


    Trazan I think you solved my problem. I checked the volume difference between return and alt input and return was slightly quieter. It can be revised by Reamp Sense value (~+7dB).
    Then at hi-gain profile noise at both these inputs is the same. So my Profiler seems to be just fine and i'm a bit oversensitive. Am I right? Big thanks for every response!

  • Check out that second video. At first guitar is plugged in the front input, normal sound. Then I plug it to the return input, set that input in input section (return reamp) and i get processed sound. Later i show you that no loop is activated. Just simple JVM preset downloaded from the site.
    Kemper Return Input processing


    Trazan I think you solved my problem. I checked the volume difference between return and alt input and return was slightly quieter. It can be revised by Reamp Sense value (~+7dB).
    Then at hi-gain profile noise at both these inputs is the same. So my Profiler seems to be just fine and i'm a bit oversensitive. Am I right? Big thanks for every response!


    Yeah, everything seems to be working correctly 8) Btw, the "return reamp" is intended for a line level signal (recorded dry guitar for reamping), not as guitar input. But you may of course use it anyway you like! As you found, you'd need to apply gain with Reamp Sense.