Unwanted Noise In The FX Loop

    I am having a problem that I am wondering if any of you are having. I am getting significant hiss/static whenever I engage a mono effects loop in position A, B,C, or D. I can get a crystal clear sound when the effects loop is disengaged. I have eliminated the possibility that the noise is coming from outboard gear as the noise in question is present even when I plug my guitar directly into the return jack at the back of the unit.


    It is particularly a problem when using the Twin 1 Clean preset


    I have included a link to some recordings so that you can hear the difference between the sound with and without the loop engaged.


    http://www.sfbmc.org/kemper/



    I contacted Kemper technical support and Sweetwater (whom I bought the original unit from). I was shipped several replacement units (six to be exact) because it was thought that there was a fault with the return jack. Unfortunately, the problem has persisted. The folks at Kemper were able to reproduce the problem, but now they are telling me that it is normal noise in an analogue signal path. I heartily disagree. I can successfully string together twenty stomp boxes and rack units and still get less noise that what I am getting with my guitar plugged directly into the Kemper unit with the loop engaged (even with no effects in the loop).


    Is anyone else having this problem? Part of why the Kemper folks are being dismissive is that they say I am the only one with this issue. If the problem is user error, I would gladly be shown the my fault and move on.


    At the very least, let me know if you think the background noise level in the 'bad' recording is acceptable or not.


    Thanks

    Edited once, last by gollum ().

    For a clean sound is quite a bit of noise. What pedal is in the loop? Try raising the pedal volume and lower the loop return volume. It sounds to me like staged gain issue.

    "Music is enough for a lifetime, but a lifetime is not enough for music" Serghei Rachmaninoff


    Thank you for your reply. There is no pedal in the loop. As I mentioned before, the exact same issue is present when the guitar is plugged directly into the return jack on the back of the unit. For this recording, the send was going to my Sound Sculpture Switchblade GL, and then back to the return of the Kemper amp. I get the same result even if I run a short cable from the Kemper send to the Kemper return though.

    The loop is a gain stage, lower the return volume and adjust the rest accordingly. Do you have the comp on before the loop?

    "Music is enough for a lifetime, but a lifetime is not enough for music" Serghei Rachmaninoff


    It is unclear to me how to adjust the gain stage as you suggest. In particular, I am not sure how to adjust the return volume. In the output menu, adjusting the direct out volume seems to have no effect on the level of the output to the loop (also, the text for that parameter is grey as opposed to the dark black of the other output parameters... I am not sure what that means). Adjusting the volume paramater within the 'loop' menu also does not seem to be very helpful. With the volume turned all the way down (which is -5db) the overall signal is lower, but the problematic noise is stillpresent at a similar ratio at to before. I am maxed out as far as input gain is concerned from my guitar, effects, or switching unit.


    I appreciate your help. Please let me know if I am missing something.

    For Testing purposes, I am simply plugging my guitar directly into the front input jack, and running the loop with a short cable going from the rear send jack directly to the rear return jack. In this instance, the only way I can increase the input signal is to turn up the volume on my guitar all the way. What is baffling to me is why so much noise is added to the output when the loop is engaged with this configuration. It sounds great without the loop engaged.


    What I intend to do in the long run is run the Kemper send into my Sound Sculpture Switchblade GL switching unit, and then back out to the Kemper return. This will allow me to patch in and out various effects in various configurations. I am able to run this setup without the Kemper and get excellent signal to noise.


    Thanks again

    The Switcblade GL is buffered, but I remind you that for testing purposes, I am not connecting it, so buffer noise does not explain the problem.


    Also.. the buffers in the Switchblade GL are amazingly transparent. Even when it is connected, i do not think it is contributing too much to the noise issue.

    Since yesterday i have my first real pedal (i only used a compressor and a big muf in front of the kpa until now) namely the G major 2.
    I put the send and return in and put the loop mono in the first spot after the amp (X think).


    There is allot of noise a very loud his. Even with the input and output levels very low on the G major.
    If i use the loop distortion the noise is almost gone. It is still there, but allot more quiet.


    I do not have any other pedal that i can use to put there. Is there some configuration problem?
    I already put the G major in Consumer mode and that lowered the noise. I tried both buttons on the back to lift ground, but nothing changed. I used patch cables and then high end balanced cables. No change.


    At work now, but will do some further testing this evening.

    Could some of you guys log a ticket with Support? I think it makes sense to bring it to their attention.

    "Music is enough for a lifetime, but a lifetime is not enough for music" Serghei Rachmaninoff


    Well as it is my first pedal (although rack mounted) i may be doing something wrong.
    I assume there will always be some noise when connecting pedals, but the noise i got is not playable.


    I will do a reset tonight and try it all again with proper gain staging to try to see where the problem lays. If i'm still stuck then i will log a ticket.

    Simple solution:


    It is mandatory to set the Clean Sens parameter in the Input to a level that is not far too low for your guitar.
    This is what your sound example sounds like.