Transient behaviour when picking the first note

  • Some great examples there, I appreciate your help! One thing that crossed my mind is that at least in my case many (if not all) of the profiles that exhibit spiking have a boost pedal as part of the profile (i.e., _not_ added as a Kemper stomp). Coincidence?


    No word from DonPetersen yet.


    Likely not, as a boost will usually raise the definition parameter.

    "But dignity is difficult to maintain
    stamina requires constant upkeep
    repetition is boring
    and you pay for grace."

  • I have got the same Issue. I realized this a long time ago, but did not bother to start a new topic (my bad)


    I checked my profile and found out I set the pick parameter +0,7. After putting +1,5 in the Compressor and reducing the pick parameter the peaks are softened but not gone.


    I used a Lasse Lammert Cabinet (an old one. I think it was from his Thrash JVM Profile or smething...)

  • Some great examples there, I appreciate your help! One thing that crossed my mind is that at least in my case many (if not all) of the profiles that exhibit spiking have a boost pedal as part of the profile (i.e., _not_ added as a Kemper stomp). Coincidence?


    No word from DonPetersen yet.


    My selfmade profile shows excessice spikes when touching the strings lightly with the pick. No booster or other pedal was involved when the profile was done.

  • Thamks for the pictures.
    I hope you don't want me to change the dynamics of the Profiler to make it look better on a scope :)


    I hope you're joking.


    We want you to fix the profiler to prevent it from clipping on signals that shouldn't be clipped.

    "But dignity is difficult to maintain
    stamina requires constant upkeep
    repetition is boring
    and you pay for grace."

  • Mr. Kemper,


    We feel that it is odd for the profiler output to go red if one just very lightly touches the strings with the pick edge. This event is associated with audible clipping and a spike in the beginning of the waveform, hence all the pictures in this thread.


    The same effect seems to take place often when one starts to play after a period of silence (especially with high-gain profiles and also depending on the playing style a bit, I guess).


    It is also unclear (to me at least) to what extent real amps behave this way.


    Any clarification would be greatly appreciated. :)

  • I put up a short snippet demonstrating the audible clip produced by the spike. Not only does it look odd in the waveform, it also does not fit in the mix that well :rolleyes: . Like Laardi pointed out it happens at the beginning of a new part, picking high strings. No extreme settings on the rig i used, Pick at +0.8.


    https://dl.dropboxusercontent.…Kemper/Click%20sample.mp3


    https://dl.dropboxusercontent.…20sample%20Git%20only.mp3


  • I hope you're joking.


    We want you to fix the profiler to prevent it from clipping on signals that shouldn't be clipped.


    Agree,this strange transient behaviour also occurs on some of the profiles I use. Please give us an update if you plan to fix this one. It's very audible spike. Can post an audio file if it helps.

  • Are they the same profiles that do this for all of you, or are they different?


    The best way to get to the bottom of this would be for everyone who gets spikes to post a list:


    Profile name
    What pickups
    Any fx pedals before the Kemper
    Clean and distortion sense settings
    All of the amp and cab sections settings
    Output settings


    This way it should be easy to spot what is in common with the profiles that produce the spikes (if any). Maybe even as you post your list look at the list posted before you and highlight the ones that are the same(ish) and add a number of total occurrences in all of the lists posted after it.

  • I received my powerrack about three months ago, so I have not done too many firmware upgrades yet. Maybe the spiking behaviour started at some point (since nobody has complained about it before).


    Would it be safe to downgrade the firmware far back in time to see if the old ones behave this way as well?


  • We've pretty much narrowed it down to be dependent on the 'definition' parameter. Above a certain threshold, it starts spiking regardless of pickups, sense levels, amp settings or effects - just 'definition'. Although someone mentioned that setting the compressor to 1.5 improves things (haven't tested it yet).


    Laardi - i'm on 2.1.something, so downgrading one level won't solve it.

    "But dignity is difficult to maintain
    stamina requires constant upkeep
    repetition is boring
    and you pay for grace."

    Edited 2 times, last by Quitty ().

  • I haven't assumed anything - i've just ruled out everything else. I think :P


    Have you tried touching the strings with your pick?
    IIRC, your waveforms looked more like sustained chords.

    "But dignity is difficult to maintain
    stamina requires constant upkeep
    repetition is boring
    and you pay for grace."

  • Those were palm mutes. Just zoomed further away than the pics you posted.


    You mean just lightly resting the pick on the strings? Nope, but one thing springs to mind if that causes spiking: bad grounding. It's possible you're getting very low voltage leaking to your strings and that gets grounded every time you touch the strings. (I was getting this at our rehearsal space that, it turned out, had illegal wiring).

  • Hmm.
    Which FW version are you on? And how are you hooking up to the DAW?


    If you get the chance, i'd appreciate it if you could just touch the strings lightly. That was the most obvious way to pull them off for me.
    Bombed! spikes like crazy when touching the strings, palm mutes do spike but not nearly as hard, low power chords spike moderately, higher power chords don't spike at all.
    Weird.

    "But dignity is difficult to maintain
    stamina requires constant upkeep
    repetition is boring
    and you pay for grace."

  • I got the spikes with a selfmade profile, definition on 6.0, Power Sagging on 2.7, Pick +0.8, Compressor 0.0. The clipping is clearly audible, see my post containing the soundclip for reference. I also had the spikes with the KM - Thrash rig, no alteration on that one (Definition on 10.0). Though it has a lower output than the selfmade rig the spikes show up just the same, lowering Definition to 0.0 does not kill the spikes. I'm using a guitar with EMG-707 with SPC preamp, pretty hot. Clean Sense -12.0 (But the spikes do not get worse even with Clean Sense set to +12.0dB as expected on a distorted tone). I think the spikes occurance is connected to the fact that the high strings are hit in my case ( and in Laardi's too), when just shredding on power chordalong i do not have any spikes, even when plaing heavy palm muted stops.

  • We could spend endless hours trying to narrow this down to something by trial and error. But at least in my case, I cannot easily investigate the effect of pick (and playing style/touch for that matter), string gauge/brand/material, guitar (and its construction/electronics), pickups, cables, audio interface, Kemper settings, firmware versions, Kemper hardware etc ... just because I don't have any extra stuff or extra time!


    So unless we collect a lot of data from many users in a systematic way, I'm afraid such a reverse engineering approach might not lead to a solid conclusion.


    My workaround so far is to adjust "pick", "compressor" and/or rig volume to prevent the peaks from clipping (yes, they are there but not clipping anymore).


    IMO, it would be best to have the mothership comment on this in a serious manner...