Bug in the Kemper cab / stack section

  • O.k. long time since I had a problem - but now I am in the trap again... can not figure it out :cursing:


    Please guys help me out!


    Here is my problem. I want to use only the "Cabinet" section of the profiler.
    - Stack: Amplifier off, EQ off, Cabinet on and LOCKED.
    - Effects all locked.
    Now when I use an external distortion pedal or a Kemper (distortion) stomp locked, this is happening: When I go through different profiles in Rig Manager (IMPORTANT: Stack not locked, but Amp and EQ turned off by hand each time) the tone is changing, although "Amplifier" and "EQ" are turned off 8|


    That means the locked cab sounds completely different depending on the used profile (even if Amplifier and EQ is off) - that is not right!?!?


    Only when I turn "Stack" off, I get the sound of the used pedal unaffected from the used profile. As soon as Cabinet is activated, changing rigs means changing sound.


    When I lock "Stack" (Amplifier and EQ still off, Cab on) - let's say with a brighter sound - than I can scroll through the rigs and sound stays brighter. When locking "Stack" with a darker tone, it stays darker - again depending on the profile in the back.


    Conclusion: I can not use Cab section independent from the profile bleeding in? Or, what am I doing wrong?


    Maybe someone can test this strange behaviour on another Kemper unit?


    EDIT: In post 7 I describe more clearly and step by step. In post 9 musicmad did a video, reproducing the tone changing.


    EDIT 2: It is a bug - see post 21

  • I'll contact Kemper support. Still could not find a way to use Cabinet unaffected by the turned off (!) amp section!


    If it turns out, that the cabs from Kemper are really affected in this way ... well I don't know how to say. I still hope it is user error!


    But I use external gear (preamps) and need the cabs and converted IR sound independent from any profile bleeding through from the background. Sound is not controllable anymore.


    Noone else has noticed this or can reproduce it? It is best heard with a distortion pedal locked. Turn off Amplifier and EQ, lock any cab and change profiles in RM. So distortion pedal through the same cab should sound the same, no matter which (turned off) Amp modul is in the back? But it does not!!!


    Sorry guys for my negative mood, I just don't know how to get the Cab section work right.

  • Doesn't loading a new profile also load the ON/OFF status of the amp and EQ? I'm fairly sure it does.


    Try locking the amp and EQ sections in their locked status.

    Yeah, it does load the on/off status to on. But when switched off again (and with the same cab) it should not sound completley different?! It seems, that as long as stack is not completely off (with stack button) the profile in the background is bleeding through and changing the tone. Or Kemper can not separate the cab part correct again?


    EDIT: o.k. I found out I forgot the rig volume; locking everything seems to work to get one constant sound. But still the profile does affect the cab before I lock; only the cab activated, sounds different with another profile. I am getting mad :S

  • It seems changing parameters on a profile (more definition, for example) does not necessary alter, how the cab section is affected (still ampflifier button off :D ) or rather separates wrong?


    I think more and more, Kemper does separate the cab different on EVERY profile, when amplifier button is deactivated - even if the same cab is used?! Maybe like in the real world, where amp and cab influence each other. But in the calculation then they do not separate the cab or converted IR correct / the same again. Could this be possible?

  • Do you experience this on merged profiles as well?

    Kemper PowerRack | Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Tannoy Active Reveal | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R8 | Fender Stratocaster HBS-1 Classic Relic Custom Shop

  • Do you experience this on merged profiles as well?

    I tested today again. I use merged profile pack in RM this time.
    Please can someone try this and compare sound "A" vs sound "B":
    - I choose a rather clean profile and add/activate Metal DS in stomp section. Then lock the whole stomps.
    - Next I Lock Effects (my Input is locked too).
    - Then I lock only the Cabinet in Stack section. Stack itself is not locked.
    - Now I turn off Amplifier and EQ: I get the sound of Metal DS through the locked Cabinet.
    This is sound A!


    - Now I change to another (merged) profile in RM.
    - Stomp section with Metal DS is still locked, as is Effects section
    - On stack section the Cabinet is still locked = the same cab as in A.
    - Of cours while changing the profile Amplifier and EQ buttons are activated again. So I turn off Amplifier and EQ againg as before.
    - Now I get the sound of the Metal DS through the locked Cabinet again (= in both cases Ampflifiere and EQ buttons deactivated and Cab locked)
    This is sound B!


    Sound A and B should sound exactly the same!
    But it does not. :S And it doesn't matter if merged profiles are used!


    Instead of locking the cab you also can copy the same cab to another profile and then turn off Ampflifier and EQ. Still the (same and copied!) cabinet does sound DIFFERENT than before.
    So in every case the cab section is massively influenced by the Amplifier used EVEN (or only??) if Amplifier is turned off. Is cab section changing sound really or just separated different each time??
    So I can not say: Ah, here is my beloved Kemper cab XY. I use this with external gear. Cause the sound of cab XY is depending on and changing with the used profile (even if Amplifiere is turned off).

  • I can reproduce your setup. I did a quick reproduction here:


    https://photos.app.goo.gl/rByG3ZVo6AwkYbHi9


    I setup with EQ locked too and then switched between merged rigs (I have to disable the amp everytime - that's what you are hearing). But the difference is pretty obvious (please disregard the sloppy playing :))

    Kemper PowerRack | Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Tannoy Active Reveal | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R8 | Fender Stratocaster HBS-1 Classic Relic Custom Shop

    Edited once, last by musicmad ().

  • I can reproduce you setup. I did a quick reproduction here:


    https://photos.app.goo.gl/rByG3ZVo6AwkYbHi9


    I setup with EQ locked too and then switched between merged rigs (I have to disable the amp everytime - that's what you are hearing). But the difference is pretty obvious (please disregard the sloppy playing :))

    Thanks for making the video! You show exactly what is happening.
    Now the question is: Bug or "just how the Kemper works"?


    In the latter case, it would be impossible to use the cab without paying attention to the profile it is dependent on.
    Lets say you want to use the Kemper with a specific IR - instead of an impulse loader. You convert the cab IR to Kemper format, load it to the unit - but then the cab section (alone) will sound differently with every profile?


    I really hope this IS a bug and can be solved. If this is "normal" behaviour of the Kemper I have to completely rethink some of my gear chains!

  • I suggest you file a bug report (include a backup and a good description of how to reproduce)

    Kemper PowerRack | Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Tannoy Active Reveal | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R8 | Fender Stratocaster HBS-1 Classic Relic Custom Shop

  • I have the latest spring reverb preview.

    Kemper PowerRack | Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Tannoy Active Reveal | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R8 | Fender Stratocaster HBS-1 Classic Relic Custom Shop

  • I have the latest spring reverb preview.

    o.k. same as me - support asked me, if the behaviour also can be noticed on earlier OS, like 5.3.1.


    I don't want to change OS just to try out - should be easy for the team to do this on their own? I wait what development department will find out in this case.

  • Yeah I'm sure they have units on different firmwares.

    Kemper PowerRack | Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Tannoy Active Reveal | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R8 | Fender Stratocaster HBS-1 Classic Relic Custom Shop

  • Can I ask why you use your KPR in this manner? I'm just intrigued as to the purpose as opposed to accuse you of doing it wrong!

    I have different setups in use. Of course I play my guitars into the Kemper in the classic ways too.


    But I own a few nice preamps and pedals that I still use. And not all of them profile equally well or they would need a power amp for profiling. So instead of my Two Notes stuff or Impulse Loader I thought Kemper will serve me well with this gear too. Especially because the Kemper cabs are said to be superior to common IR.


    I also have collected and made myself some power-amp-only profiles. So the chain is for example: Tube-preamp or pedal into Kemper with power-amp-only di profile + cab section. This chain also has less latency as using vst.

  • Can I ask why you use your KPR in this manner? I'm just intrigued as to the purpose as opposed to accuse you of doing it wrong!

    I would say it's a very generic problem if it ends up being a fact that cabs sound different depending on what amp is loaded.

    Kemper PowerRack | Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Tannoy Active Reveal | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R8 | Fender Stratocaster HBS-1 Classic Relic Custom Shop

  • I would say it's a very generic problem if it ends up being a fact that cabs sound different depending on what amp is loaded.

    Kemper team didn't report back so far. I don't want to speculate too much at this time. But there seems to be some kind of "interaction" between amp and cab section, that is not comparable to an amp di signal going through some impulse loader with a "fixed" IR. Maybe one can call this "simulating" real interaction between amp and speaker. But as soon as cabs are not used with the initial amp or some converted IR are loaded in the cab section, that kind of interaction leads to "unpredictable" outcome - at least in comparison to other solutions. I have the fear, that this is part of how the Kemper unit works and they can maybe try to calculate the separation between amp and cab better (when one section is disabled) - to a certain degree. Or maybe they will explain, why this has to be that way (worst case). And an Achilles' heel will persist. That all is just my fear!


    I REALLY hope, I am completely wrong and it is "just" a bug they can solve with an update soon.