Making sense of clean sense (audio clips added)

  • OK, I know that clean sense has no bearing in Kemper land other than ensuring that clean profiles and distorted profiles are adjusted to the same level.


    That said why on earth does my Kemper sound different if I reduce the clean sense while playing through a distorted profile? For a test:

    1) Set your clean sense to 12 and then play the profile (ignore the input LED if it clips, as Kemper Amps has told us, use your ears and not your eyes)

    2) Set your clean sense to -12 and play the profile.


    When I say sound different, what I mean is that my input signal seems thicker and the profile more "congested/saturated" (for want of a better word) when I have the clean sense set high.


    But when I lower clean sense, I also notice that the signal seems to clean up and so does the resultant sound... An overly hairy profile suddenly becomes less hairy, sort of like if you were using lower gain pickups.


    Here's what Kemper Amps says:

    Clean Sens

    Different types of guitars produce different output levels depending on their pickups and string gauge: for example, humbucker pickups generate higher voltages compared to single coils, and active guitars generate even hotter signal levels. If you feel that clean sounds are either very loud or very soft compared to distorted sounds, you can adjust Clean Sens to a level where clean sounds have the same perceived loudness as distorted sounds. Clean Sens determines the volume of clean sounds, but not the way that the amp or the effects are driven. A guitar with low output level stays cleaner; a hot guitar will still distort more easily.

    Extremely “hot” guitars can generate unwanted distortion, indicated by the INPUT LED flashing red. This is only relevant for clean sounds, however - prominent amp distortion will completely mask a subtle clipping of the input.



    One more thing I don't get:


    INPUT LED (2)

    The LED reflects the level of the input signal. Its base color can be changed from green to blue with the option Signal LEDs Blue in System Settings.



    OK, so it reflects the level of the input signal and nothing else.


    If that's the case, why does it stop clipping if I reduce clean sense on a guitar that blinks red?


    At work, but I'll try to do a recording tonight if I can to demonstrate high clean sense versus low clean sense.

  • nightlight

    Changed the title of the thread from “Making sense of clean sense (again)” to “A bone to pick: Making sense of clean sense (again)”.
  • https://www.dropbox.com/s/6bma…sz/Clean%20Sense.wav?dl=0


    Here's a clip.


    First part of the clip is the clean sense set to -12. The second is +12. Then a short section with palm mutes at -12 and ends on +12.


    I can definitely hear more chunk and sustain on one part than the other, but what's weird is that when I flip to the palm mutes, I think the one with less chunk and sustain sounds better than the one with more.


    Now here's the first part for both tracks, -12 and +12.


    https://www.dropbox.com/s/roaq…lean%20Sense%201.wav?dl=0


    https://www.dropbox.com/s/4n4e…lean%20Sense%202.wav?dl=0


    I'm totally convinced it's not just a difference in the way I'm playing it. On the +12 track, I can hear more saturation or compression. On the other, I hear less. I can even hear it on my Mac speakers, but it's even more audible when I use my room treatment plugin and listen over monitors.


    There isn't a way to do This with a DI track unfortunately, otherwise I would have taken the difference in playing out of the equation.


    Given that the LED doesn't matter at all according to Kemper, seems to indicate there may be benefits to setting clean sense on a per patch basis...


    That is assuming everyone hears the same difference I do.

  • nightlight

    Changed the title of the thread from “A bone to pick: Making sense of clean sense (again)” to “Making sense of clean sense (audio clips added)”.
  • As far as I can make out Clean Sense is actually BOTH an input gain control AND a master balance control between clean and distorted profiles.


    Therefore, reducing the input gain makes the LED

    Stop flashing red. Increasing the input gain (Clean Sense) means that more signal is also hitting the distorted profiles so fattens them up.

    However, I believe the unit has so much headroom and employs soft clipping that the input gain function is almost irrelevant hence the reason the manual doesn’t really explain it.


    I could be wrong but that’s definitely how it appears to me.

  • I think it’s spot on and is exactly what I've come to believe as well.

  • From everything I’ve tested clean sens is output only. It just affects the level of the amp output when the gain dial is lowered. Thus it allows you to control the balance of volume between gain settings to overcome the amp getting quieter as gain is lowered.


    You can test this by placing a distortion stomp in line and seeing whether it reacts (cleans up or not) as you adjust clean sens. It will not


    Distortion sens meanwhile also doesn’t affect input volumes, even though you might think it does because it lowers the distortion instead it’s actually simply modifying the gain level of the amp. You can likewise test this with stomps seeing what is affected and where.

    What I have noticed with the Kemper is that any clipping at all, no matter how small will result in nasty digital clipping artifacts. It has no “soft clipping”. If you want to accurately represent a profile you need to make sure that most importantly your output LED never ever touches yellow. Green and bright green is as far as it should ever go. Yellow indicates that some clipping is occurring, red means more than a certain percentage of the waveform is being clipped (maybe 50%? Not sure how much but enough to devastate the tone). Anyhow, in general I have clean sens set to bare minimum to avoid the fizzy distortion effect, but keep volume even-ish between clean and dirty settings.

  • I should have added - If you are finding clean sens is thickening up the distorted tone it is because you are adding hard clipping to the output. This at lower levels this seems to thicken the tone because it’s introducing smaller quantities of aliasing harmonics, these can be any frequencies at all rather than the usual even/odd. The more hard clipping that occurs though the more fizzy or rather fuzzy the tone becomes until eventually it breaks down completely. I believe this is often the “characteristic Kemper tone” that some people complain about or “sameness” and is to me purely user error.


    Basically Kemper output is hard clipped. Surprisingly the input seems much more forgiving.



  • Not at all what Kemper Amps says though when it comes to what it does. Read the manual, it's only supposed to be used to balance clean and distorted tone volume levels.


    Mods have also said several times, clean sense only affects volume balance between clean and distorted tones. That's why I posted the test, it just doesn't work that way.

    From everything I’ve tested clean sens is output only. It just affects the level of the amp output when the gain dial is lowered. Thus it allows you to control the balance of volume between gain settings to overcome the amp getting quieter as gain is lowered.


    You can test this by placing a distortion stomp in line and seeing whether it reacts (cleans up or not) as you adjust clean sens. It will not


    Distortion sens meanwhile also doesn’t affect input volumes, even though you might think it does because it lowers the distortion instead it’s actually simply modifying the gain level of the amp. You can likewise test this with stomps seeing what is affected and where.

    What I have noticed with the Kemper is that any clipping at all, no matter how small will result in nasty digital clipping artifacts. It has no “soft clipping”. If you want to accurately represent a profile you need to make sure that most importantly your output LED never ever touches yellow. Green and bright green is as far as it should ever go. Yellow indicates that some clipping is occurring, red means more than a certain percentage of the waveform is being clipped (maybe 50%? Not sure how much but enough to devastate the tone). Anyhow, in general I have clean sens set to bare minimum to avoid the fizzy distortion effect, but keep volume even-ish between clean and dirty settings.


    Ah, but Per , assuming your input is clipping, how do you fix that?


    Do you (surprise surprise) lower clean sense?


    Also, you should read those references to the manual. Kemper Amps says that just occasional excursions into the red don't matter with the output. Neither does red flashes on the input. And if indeed clean sense has no effect on the input, it is moot point anyway, since you will never be able to stop the clipping.


    Also, did you listen to my clips. Definite difference in tone. Yes, there is a difference in the playing, wince I couldn't reamp, but there's also definitely a difference in tone.


    Anyone can do a recording and verify this.

  • You adjust the volume pot on your guitar.


    Try what I suggested. Just because these settings are in the input section doesn’t mean they actually affect the input.


    I absolutely disagree with the manual on the clipping, again experimentation will show you exactly what the effect is. It certainly will “thicken” the tone, but not in a good way. Try just raising the output volume on the same rigs to see the difference.

  • Not at all what Kemper Amps says though when it comes to what it does. Read the manual, it's only supposed to be used to balance clean and distorted tone volume levels.

    As Shakespeare would say “a rose by an opt name would smell as sweet” or to put it another way : if it looks like a duck, walks like a duck and quacks like a duck- it’s a duck ?


    if you reduce the clean sense to -10db (perhaps there’s a clue in the choice of measurement too) the input led will go to green or even very faint green depending on pickup strength. If you increase it to +10db the led wil glow full red with even relatively low output pickups. That looks a lot like a gain control to me.

    I thought I remembered even Kemper saying previously that it performed a dual function but the no longer do. My thinking is that they stopped saying this because people were fixating on setting the gain level which in reality is almost irrelevant as there is so much headroom and the input and output soft clip anyway. Or maybe I am just dreaming it ?

  • You adjust the volume pot on your guitar.


    Try what I suggested. Just because these settings are in the input section doesn’t mean they actually affect the input.


    I absolutely disagree with the manual on the clipping, again experimentation will show you exactly what the effect is. It certainly will “thicken” the tone, but not in a good way. Try just raising the output volume on the same rigs to see the difference.


    Lowering the volume knob on your guitar seems like the least optimum way to do this, I would think. I wouldn't do that with any real amp, and there's absolutely no need to do this with the Kemper either, imho.


    I thought I remembered even Kemper saying previously that it performed a dual function but the no longer do. My thinking is that they stopped saying this because people were fixating on setting the gain level which in reality is almost irrelevant as there is so much headroom and the input and output soft clip anyway. Or maybe I am just dreaming it ?


    I don't think they've ever said that. They've continuously maintained that clean sense is only to balance the volume between clean and distorted profiles.


    The clips I provided seem to indicate that there indeed is a difference in tone, leaving the worries about clipping aside.


    Here, I did a bunch of tests and experiments in this thread a gear or two back What are your ideal settings?

    I did a test too, did you check the clips? I could do the tests again and the results would be the same.


    In that thread, you mention clipping in the output section. I wouldn't mess with clean sense for that, reduce rig volume.


    As far as clipping in the input section, Kemper Amps says use your ears not your eyes.


    But that whole direction doesn't explain why the tone changes with different clean sense while using distorted tones.

  • Hey there, yup I check out your files. Actually I should clarify. input sens modifies the output volume/clean blend for the amp block. You can see the methodology I used to determine this in post 16 of that thread.


    If you have any effects after the amp block they will be affected by input sens settings. Check what’s there on this rig.

  • But if you put a Loop in Stomp A and send this to an amp, interface or dask and check the level hitting them you will see that this also happens for literally the first point in the chain. Therefore the logical conclusion seems to be that it does work on the input section not the output.


    You can also see this on the KPA itself by monitoring the input LED. High CLean Sens settings turn this bright red whereas low Clean Sens leave it green. That should be monitoring the input signal not the output. The LED measure doesn't change even when no processing is being applied. You can test this by turning off all blocks (Stomps, Stack and Effects) just for good measure. Now set Main Output to Git + Processing. The manual clearly says that this mearly sends the input guitar signal straight through at the same level as it came in but it passes through the AD/DA converter first. Changing Clean Sens makes no difference to the audible output level (which is confirmed by the input meters on the desk). However, the LED still changes from green to red and if I hit the strings hard enough I can make the sound clip even though the level hasn't changed. To my mind, that implies the signal is being clipped on the input AD convertor but the level is being adjusted later in the chain before sending back out through the DA converter.

  • nightlight there is clearly a massive difference in the sound of the two profiles you posted. However, I can't replicate that effect at my end. Is that one of your own profiles or a commercial profile?


    I have kust reamped a quick riff using one of the factory profiles OLA - Haende KY RHY


    Recorded it three times 1 ) Clean Sens -12db, 2) 0db 3) +12db There may or may not be slight differences between the three but definitely not anything to write home about.


    Clean Sens test

  • But if you put a Loop in Stomp A and send this to an amp, interface or dask and check the level hitting them you will see that this also happens for literally the first point in the chain. Therefore the logical conclusion seems to be that it does work on the input section not the output.


    You can also see this on the KPA itself by monitoring the input LED. High CLean Sens settings turn this bright red whereas low Clean Sens leave it green. That should be monitoring the input signal not the output. The LED measure doesn't change even when no processing is being applied. You can test this by turning off all blocks (Stomps, Stack and Effects) just for good measure. Now set Main Output to Git + Processing. The manual clearly says that this mearly sends the input guitar signal straight through at the same level as it came in but it passes through the AD/DA converter first. Changing Clean Sens makes no difference to the audible output level (which is confirmed by the input meters on the desk). However, the LED still changes from green to red and if I hit the strings hard enough I can make the sound clip even though the level hasn't changed. To my mind, that implies the signal is being clipped on the input AD convertor but the level is being adjusted later in the chain before sending back out through the DA converter.

    I found you need to ignore the input LED. Check my post in the linked thread.


    It's possible that once a loop is used it changes the location within the signal chain of the change, however you can demonstrate that when no loop as active the clean sens only affects things after the amp block.


    The easy way to see this is simply using the test case in the linked thread. As you know, a distortion stomp will sound more distorted the higher gain the signal going in to it. This makes it easy to determine if there's an actual change in signal level reaching that stomp. Place the distortion stomp before the amp block and play with the sens settings. The distortion will not change. Place the same stomp after the amp block and then when you play with the sens settings the distortion will increase and decrease with the sens values.


    This makes sense too, as sens is listed simply as the level balance between distorted and clean settings on the amp block. If clean sens actually modified the input gain then the amp would become dirtier the higher it got, the same as with a real amp. The same as if you raise or lower your volume pot on your guitar. It doesn't. Instead you get a clear blend between two signals clean and distorted if you raise it too high. It's sort of a parallel path behavior.

  • This is a great thread but it has left me with some confusion as a new Kemper owner.


    1) If my input blinks a light red, do I need to worry about it? IF yes, what is the first thing I should be lowering?


    2) What is the best way to match volumes between clean channels and distorted channels? Is it with the Clean sens or rig volumes?

  • It’s a confusing subject because the assumption is that the sens settings being in the input section would affect the input. They don’t.


    Even worse they affect the so called Input LED. But it doesn’t even appear to be the input LED, it’s the output LED for the clean portion of the signal at some location in the signal chain.


    Clean Sens is not Input Gain.

  • nightlight there is clearly a massive difference in the sound of the two profiles you posted. However, I can't replicate that effect at my end. Is that one of your own profiles or a commercial profile?


    Clean Sens test



    I'm not sure how to assuage that concern other than to shoot a video while capturing the audio.


    Re: your clip. Comparing the first to the third. There's definitely a difference in the amount of compression and saturation. I can even hear that on my phone.


    Anyone else can have a listen and see whether they agree.

    The easy way to see this is simply using the test case in the linked thread. As you know, a distortion stomp will sound more distorted the higher gain the signal going in to it. This makes it easy to determine if there's an actual change in signal level reaching that stomp. Place the distortion stomp before the amp block and play with the sens settings. The distortion will not change. Place the same stomp after the amp block and then when you play with the sens settings the distortion will increase and decrease with the sens values.


    This makes sense too, as sens is listed simply as the level balance between distorted and clean settings on the amp block. If clean sens actually modified the input gain then the amp would become dirtier the higher it got, the same as with a real amp. The same as if you raise or lower your volume pot on your guitar. It doesn't. Instead you get a clear blend between two signals clean and distorted if you raise it too high. It's sort of a parallel path behavior.


    I think framing this as something that affects distortion is not accurate. Listen to Wheresthedug 's clips and listen to mine. It's a similar difference between the -12 and the +12 clips in terms of the compression/smoothness and sustain/saturation of the tone. The distortion is pretty much the same.