[Public Beta] PROFILER OS 8.0.0.21450

  • Thanks for testing!

    I can even hear the volume stall at 0 dB. A small drop in volume.

    This is - as said - made by the known volume compensation that rises the amp volume.

    The volume compensation is made for maintaining the output level at low amp gain values.

  • Making a conjecture... maybe the currently discussed issue exists because of Kemper's fixed-point processing -- at a certain point, the drive processing portion's dynamic range runs out and the volume increase does strange things because it meets an overflow limit. Seems a complicated issue to solve/optimize if this is the case. End of conjecture.

    The processor we use is 24 bits, which accounts for a 144 dB of dynamic range. 288 dB when used with double precision.

    There is not even a handful of situations where double precision is needed.

    The AMP Gain range spans through 80 dB.

    Very comfortable :)

  • Any data overflow would present itself as random aberrations, not what is being described. Most processors just go "blue screen of death" and thats it. So no, dynamic range its not the problem, as mr kemper described, 24 bits of dynamic range is pretty much overkill for any function. Except audiophiles, those guys truly believe they can hear the difference in a recording with 24 bits to 32 bits, who knows....

    The answer is 42

  • Thanks for testing!

    :thumbup: Happy to help.


    I can even hear the volume stall at 0 dB. A small drop in volume.

    But is this a normal way of an amp or pedal to react when you rise the volume? I mean, to compress and get more distortion without more volume I understand. But a drop in volume even if it is small, does it happen in real pedals and amps? This is an honest question. I don't know.

  • :thumbup: Happy to help.


    But is this a normal way of an amp or pedal to react when you rise the volume? I mean, to compress and get more distortion without more volume I understand. But a drop in volume even if it is small, does it happen in real pedals and amps? This is an honest question. I don't know.

    No, this does not happen on real amps.

    Because real amps don't feature this volume compensation.

    However, with a guitar connected to the Profiler input the drop will not happen, still you will notice the volume compensation.

    Try it out.


    When you do reamping, you will aim to achieve the same guitar volume. Same result.

    When the reamping volume is much higher, as it might have been in your 0 dB example, then you might experience a plateau or even a volume drop.


    Same happens with just a profile and no overdrive involved, but the Clean Sens set much too high.

    Chose your favorite Rig with just the AMP and CAB active.

    Turn up the Clean Sens to exagerated +12 dB.

    Check the AMP Gain at zero versus high settings.

    You will notice that the clean sound (zero gain) is much louder than the distorted sound. Very unnatural

    Now check the transition between Gain 3.0 and 5.0 (roughly).

    You will notice an intense volume drop of the already compressed signal.

    This is due to the Clean Sens being set to anticipate a much softer guitar, and changing the volume compensation accordingly, but wrongly.

    Setting the Clean Sens correctly is to create equal volume at clean and distorted amp.

    That is equal to a "volume stall" as you say.

  • The processor we use is 24 bits, which accounts for a 144 dB of dynamic range. 288 dB when used with double precision.

    There is not even a handful of situations where double precision is needed.

    The AMP Gain range spans through 80 dB.

    Very comfortable :)

    So what causes the issue described by lightbox and others? :)

    Any data overflow would present itself as random aberrations, not what is being described. Most processors just go "blue screen of death" and thats it. So no, dynamic range its not the problem, as mr kemper described, 24 bits of dynamic range is pretty much overkill for any function. Except audiophiles, those guys truly believe they can hear the difference in a recording with 24 bits to 32 bits, who knows....

    I should've made it clearer -- my conjecture was not about the effect of overflow itself but about the effects of a possible internal "overflow limiter" if you will.


    We know the KD volume knob gives 24 dB of gain, and the gain knob probably gives upwards of 40 dB of gain. If @ single-precision 144 dB, that leaves ~84 dB dynamic range for the guitar signal going into KD. Maybe with unexpectedly high level gain staging into the Kemper, and with the KD knobs turned up, the it hits an overflow prevent limit...?

    This idea has already been debunked by CK, so I'm just having fun now. Hope he finds out what's wrong and can fix it soon, and maybe shares with us what it was for funsies.

  • Any data overflow would present itself as random aberrations, not what is being described. Most processors just go "blue screen of death" and thats it. So no, dynamic range its not the problem, as mr kemper described, 24 bits of dynamic range is pretty much overkill for any function. Except audiophiles, those guys truly believe they can hear the difference in a recording with 24 bits to 32 bits, who knows....

    I am a true fan of audiophiles talking about sample rates and bit depths ;)

    Usually they don't have a clue what the sonic effects of small bit depths are, and they don't even care.


    But you can try it out with the Profiler.


    Put a Bit Shaper into the X Module and try the Drive knob to reduce the bit width.

    Have fun with it, because it's mainly created to be a lo-fi effect (Bit Crusher).

    A reduced bit width is mainly identified by a noise floor that disappears when you stop playing.


    Now set Drive to 1.2.

    This is 10 Bit.

    Check the difference by switching the Bit Shaper on and off.

    I can hear the difference.

    Turn up the Noise Gate to bring down the noise from your guitar, as it might mask the bit reduction in the way Dithering is used.


    Set Drive to 1.0.

    This is about 13 Bit. Equals to 18 decibels less noise than at 10 Bit.

    Equal to 78 decibels dynamic range, approaching the noise floor of the best analog tape machines.

    Can you hear a difference?


    Set Drive to 0.7.

    This is 16 Bit.

    Audio CD quality.

    Another 18 decibels better than above (13 Bits)


    Set Drive to 0.0

    This is 24 Bit.

    In theory 48 decibels better than Audio CD quality.

    In practice, limited and counteracted by noise floors of analog electronics.

    Bit depth has never been a limiting factor when handled properly.

    The rest is urban myths.

  • Setting the Clean Sens correctly is to create equal volume at clean and distorted amp.

    That is equal to a "volume stall" as you say.

    Can’t we just set amp or rig volumes to compensate for these cleans being too loud instead of making the Kemper adjust for it with Clean Sens?

    I was very late to the Kemper so I don’t understand why we need Clen Sens instead of just levelling a clean rig manually with amp or rig volume. Is it something else I am missing?

    I know between a Les Paul and a Tele through a normal amp that there is an output difference but that is what we love about choosing each of those. It’s a different sound and texture.

    What I don’t like is having to set a Clean Sensitivity that only works for a Les Paul OR a Tele but not both. It’s something that does not happen using a real amp, you just plug in and that’s it. You know what you are going to get from each of those guitars.
    I am not talking about unlocking the input section for each profile. Just about being able to plug any guitar in and not have to worry about Clean Sens.
    Sorry if this is derailing the thread. Just trying to understand the what it does, why it has to do it and if it needs to do it aspect.

  • What I don’t like is having to set a Clean Sensitivity that only works for a Les Paul OR a Tele but not both. It’s something that does not happen using a real amp, you just plug in and that’s it. You know what you are going to get from each of those guitars.

    You don't have to do that. If you want to use multiple guitars, and have each of them react like they normally would, you can level the Rigs for relative volume, and leave both Sense controls on "0".

  • Thanks for testing!

    I can even hear the volume stall at 0 dB. A small drop in volume.

    This is - as said - made by the known volume compensation that rises the amp volume.

    The volume compensation is made for maintaining the output level at low amp gain values.

    If Clean Sens is at 0 does this defeat the volume compensation completely?

  • So what causes the issue described by lightbox and others? :)


    This idea has already been debunked by CK, so I'm just having fun now. Hope he finds out what's wrong and can fix it soon, and maybe shares with us what it was for funsies.


    Hard to say.

    lightbox is experienced.

    He might have encountered that same plateau effect caused by the volume compensation, that we discuss here.


    One hint could be his recommendation to push the volume for the reamping.

    However, if his very large volume drop was a side effect of the high level reamping, then he purposely choosed a very exaggerated reamping volume that gave him a much more gainy sound than by playing the original guitar level. Usually you would try to approach the original guitar level for the reamping signal.


    If that was the case, then he additionally suppressed the valuable information that the volume drop or plateau would not appear at lower guitar level, e.g. when you just play your guitar through that same rig, as Atlantic demonstrated. It‘s hardly probable to overlook this level dependency when you keep your self busy with this topic for hours (as he said). But this level dependency would be the key for finding the cause of the volume drop.


    Why would he skip this information?

  • When you playback the hard strumming DI into the Profiler (make a loop in your DAW!), make sure that the Profiler's input LED very briefly goes into yellow at least for the hard strummed transients! In your DAW you can adjust the levels accoringly just in case your DI track was too hot or too low. This step is crucial!

    Who skipped it? Was it you in your shortened list or me in my complete list? ;)


    And since your next question might be WHY I came up with this:

    I tried to compensate for the lack of boost in the KD compared to my Klon clone or Power Boost pedals.

    I thought I will just try to push the reamp signal a bit to see what happens. And that's when and how I discovered this effect.


    PS: May I say that I wasn't aware of this "volume compensation" stuff before? There's quite a few things I wasn't aware of until I started to dig a bit deeper.

    One other example of what I didn't know and expect is that "unity gain" in the Kemper Drive doesn't seem to be at the default Volume 0.0 but somewhere around +0.8 or +0.9 roughly. It's not that easy to get your head around the internals as " a regular user". I stumbled over many weird effects and tried to make sense of them. But that takes time.

  • Please guys, if you want to argue, then do this via PM, email or by phone. This thread is getting nasty, and I don't think anyone still wants to read this and filter through the trash to find the real beta-related issues. The issue is clear: if you re-amp with a loud input, the KD behaves in a certain way if the volume is also hot. This is at times reproducible, and sometimes not. And that's the end of it, because Martin is not able to send an entire backup to the Kemper team.


    So, please let's discuss the KPA here, I love the KD, and I hope there will be a second KD, which would be the Kemper Distortion. And of course a KF, with octaves function (all-in-one). Then comes the KC (compressor) with different flavors... Hmmm... I see a trend here.

  • I held off making the same comment myself....


    No idea why its become a tit for tat but can we quash it? This forum has been so positive and the drives are a big step forward.


    I don;t think anyone is being deliberately evasive or destructive, just describing observed behaviours under certain conditions.


    If these conditions are deemed " not normal" or expected/designed in, then state why. I'm not clear if its reproducable or not - this would determine if a bug exists.


    If I did reamping then I would try, but I don;t so can;t help/comment.

  • the real beta-related issues

    I understand your sentiment but even though Christoph and I might sometimes (or often) disagree, the purpose of discussing a beta is to discuss "issues" ... which is exactly what I (and others) do here. If you just want to share that you "love it", fine. But it doesn't contribute to find and tackle quirks and/or issues. ;)

  • I understand your sentiment but even though Christoph and I might sometimes (or often) disagree, the purpose of discussing a beta is to discuss "issues" ... which is exactly what I (and others) do here. If you just want to share that you "love it", fine. But it doesn't contribute to find and tackle quirks and/or issues. ;)

    Discussing issues with the software is great, discussing issues with each other not. I did not only shared I "loved" it, just search the thread for my posts. And posts saying "I LOVE THIS!!!" are also very valuable for a beta test, in my opinion. This is my final remark on this topic, happy testing!