Fizz on Kemper (audio clip)

    Quote from Jaywarren

    Here is a link to an audio clip of the issue:-


    https://www.dropbox.com/sh/5ta…ue%20-%20Jay%20Warren.aif


    Did you try the reset as per the wiKPA manual?https://www.dropbox.com/s/2pahwk9nk7ha6x4/Gianfranco%20Di%20Mare%20-%20wiKPA%202013%2002%2003.pdf


    The process is a little bit more than you described earlier - I followed the method on page 19 of the wiKPA manual.mlots of other really useful stuff in there too! Good luck.

    You're damned if you do and damned if you don't

    I have a similar issue (and it persists after a system reset) too. I also hear the fizz at the tail end of chords played. This happens on clean profiles.
    Im not sure why this happens - but am unable to work around this. Would appreciate some help on this as well.


    Thanks a lot!

    Guys who are getting this, where do you have set your channel volumes?


    Afaik, aliasing is introduced into audio when the bitrate lowers and headroom runs out if the volume is ran too high. (At least that's what I gathered from this video):


    http://www.youtube.com/watch?v=oJ6M-JDyeXU


    It could be I didn't understand his lecture at all though. :P


    EDIT: Now that I think about it, just making sure your output doesn't clip should prevent the aliasing he's talking about in the video.

    I hear no big problem it is very subtile on the posted files. My assumption is that the clean sense is set too high. Try to turn it down. You can emphesize this effect by using the wahwah. I hope this helps.

    I tried 1.6.1 and same issue.
    I have recorded another clip with my latest finding!


    I have input sens on 0 and all LED's stay green the whole time. This is now using a different clean amp (Topboost clean again from TAF). The clip starts with the profile as it loads. Then I disable the verb and pedals. Then I take off the EQ and cab. You can REALLY hear the issue then. Next I turn off the amp itself and the clean sound is perfect with no distortions. Finally I turn it all back on to have the same issues.


    http://dl.dropbox.com/u/65467310/Kemper_Issue_v2.aif

    Hey Jay,


    I replied to your PM but thought I'd post it publicly as well. One of Andy's AC30 profile's that I've tried has some weird artifacts going on and I suspect your using it or some variation of it. You should try some other profiles out and see if the issue is consistent.

    Quote from Jaywarren

    Thanks for the info Will. I just tried the Trainwreck profile and a few others and the issue is identical. You can hear the issue pretty clearly right?


    What I hear is a massive amount of low end which sounds like its distorting something either internally in the KPA or whatever interface your using to record. At first I thought I was listening to a bass guitar. The artifact I mentioned doesn't quite sound like that. How hot are you pickups and how close are they to the strings?

    Thanks again for the response Will. So I am hearing this using a Strat, PRS and Tele. Pickups are vintage in the tele and not hot at all. All guitars have recently been setup and the pickups are not too close. This has been recorded using an Apogee Duet 2 into Logic. All levels are healthy and green throughout. I also hear exactly the same thing through headphones directly from the Kemper.

    Hey Jay,


    I hear what you're talking about - but as Will notes - there's a massive low-end in the sounds that you've selected. I have some of the free TAF stuff (with 1.6.0 i.e.) - and to be honest - they're not to my taste in terms of EQ and how I like my guitar to sound. That being said - I do love some of the other stuff that I've heard - and will get some soon. I've used my trusty Ibanez with DiMarzio pickups to record this.


    Anyhoo - Here're links to 2 clips I recorded - off the SPDIF into logic. No post-processing done - what you hear is what was recorded:
    The settings are:


    Input sense was at 3.0.
    Clean1 was recorded using Till's Recto Clean. The first half is only the Amp, tone stack and cabinet - I turned off the pedals and the effects for this one. The second half is the pedals turned off and ONLY effects turned on. Listen to the crackling - very clearly heard over the chords being played - especially watch out when the chords fade out to silence - you can still hear the crackling - and then silence - I dont really buy the 'clipping' argument - sorry. If it was a clipping artifact - I should have only heard it when the signal was LOUDER .. and it should not have been hear when it was fading out, right?


    Clean2 - the crackling is tougher to catch - but still exhibits the issue (which is why I've posted this clip as well). This is based off a Kemper amps SOULDANO profile (love some of the Kemper profiled stuff - TOP CLASS). I've turned off the pedals for this one - and only turned on the effects. Again - input sense is low - it's at 3.0. No clipping was observed ... input LED was green throughout. This was a profile I modified for some stuff that I was doing. The 'crackling' is harder to catch for this one - but still there. It's in fact strange how it presents itself - if you listen carefully - it doesnt happen the first time around (when I strum the G chord and let it fade). But the second time around, when the G chord fades - you can hear it quite clearly. Again - I dont think that this is clipping - and am worried that discrepancies such as this could also creep into other aspects of my TONE :(.


    Clean1 - http://dl.dropbox.com/u/89893924/clean1-spdif.wav
    Clean2 - http://dl.dropbox.com/u/89893924/clean2-spdif.wav


    As many of you who cannot hear the crackling/fizz in these clips can attest - the Kemper STILL sounds pretty AWESOME and extremely useable (especially live). But to my ears - this reveals that - there's still things to be learned about this beast - and I would appreciate an explanation as to how I can avoid these artifacts from creeping into my work from now on (For example - earlier posters mentioned pickup-string distance)? OH - BTW - I can hear this stuff on my monitors - and headphones as well. I have not used fancy spectrum analysis tools to further prove my point - but I can provide a graph if required.

    Gorillabendz, I can hear it on your clips and find it incredibly annoying! It leaps out to me... My clip is pretty gnarly as I was trying to show the issue in its worst state... ;)
    I hope this can be resolved with Kemper as I have spent alot of money on AF models that I can't return!
    Apart from this issue the Kemper is amazing :(

    Ah, now I can hear a slight digital clipping when I listen through my headphones instead of my monitors.


    Sounds sort of similar to what happens when you have your sound card settings wrong, like when the internal bitrate (or something along those lines :P ) is set wrong between the hardware and software.


    EDIT: Yes I can hear it in my KPA as well on the Acoustic profile of Ruppert through the headphone jack. Maybe some sort of foreign element during the creation of these profiles made them glitch? The rest of my clean profiles are clipping free. (ToneKing by And44).


    I'd think the problem lies within the profiles themselves, since only some do this and they're the only variable.