Petition: Total cab bypass on monitor out

  • Many of us have talked about it in many threads, but i think it is about time we get this function soon. So this could be the thread where we can speak with one voice. If enough of you "sign" perhaps this will move Christoph Kemper to integrate it.


    To sum it up, here´s the short story: If you want to use your KPA in combination with a poweramp and a guitar cabinet you have the opportunity to use the "cab off" function in the Master section. However, a small part of the cab portion remains in the signal chain. CK stated this is by intent, in order to not make every profile sound the same. So it is definetely not a limitation of the KPA, but a "feature". However, the tonal results are very poor, making this solution nearly unusable for most users. The workaround for many of us has been to use DI profiles without cabs enabled on them. Though this works nicely for the "monitor out" kind of use, it renders the main function of the KPA useless.


    Please, Kemper Team, make an option for "total cab bypass" available!!!

  • Me too, definitely. This has been my major gripe from the start.
    Sometimes when I direct profile I manage to get it where the entire profile is in the amp section and the cab section is 'empty'. It seems strange that adding a cab effects the monitor out even when cabs are switched 'off' there.
    It would be great to be able to do a direct profile, send that via monitor out to a power amp/cab, and add a cabinet to the main outs.
    If this proves to be impossible due to the profiling system, then at least making one of the fx slots able to handler irs would be present only on the main outs would be a compromise.

  • a small part of the cab portion remains in the signal chain. CK stated this is by intent, in order to not make every profile sound the same. So it is definetely not a limitation of the KPA, but a "feature".

    I'm afraid the two things are not necessarily consequential. They might have done it on purpose but, AFAIK, there's no mathematical way to really separate the cab contribution to the sound from the amp part: simply not enough information acquired during the profiling process. This issue has been long discussed on other boards (see TGP for example). It's like three people, each one putting identical glass marbles into a box, mixing them and then trying to tell whose which one was. I'd really like to be proven wrong on this, but can't see any mathematical way out :( Eng. Kemper, feel free to correct me if I'm wrong here.


    At the moment, the KPA seems able to "just" (!) take a snapshot of a
    whole sound chain (we all know how well it performs the task, and how fascinating and musical the results are); this also explains why the amps alone sound more
    similar to each other than their real counterparts.


    I can see two possibilities for a real cab separation to be available:

    • the profiling process actually implying two profiles to be taken, one of which from the amp Power Out (and w/o any intermediate box, which would add its own impedance and transfer function anyway);
    • the profiling process actually implying two profiles to be taken, one of which involving the cab alone. Note you'd have the cab+mic anyway, never the cab in itself (for the same reasons).

    This could actually be a solution for a next hardware incarnation: adding a Power Amp In or a Cab Out socket to the KPA for a differential profiling. This would require more sophisticated algorithms tho: the generic amp/cab model would be more complex for responding to the real behaviour of the amp/cab alone, and they should implement specific code for the interaction between the amp and the cab... This would require more code, more real time number crunching, and more CPU power for managing it: if you bring it any further, you see this quickly leads to a completely different beast: someone else has already tried this approach, ending up creating the Axe-Fx.


    Of course Kemper saw no reason to produce an Axe-Fx clone. There're no shortcomings if you want to compete with the AXe-Fx: you need same hardware power, same code complexity, and in the end (providing one can write such good code) same price. And I believe, as far as I know Eng. Chase, its prices are very low. That's why Behringer will never produce an Axe-Fx: because Axe's power/price ratio is optimal, there's no margin for making it cheaper and equally powerful (I'm sure TigerSharks will cost 1$ in 10 years. But at that time an "Axe XX" would use something more powerful, and keep garrisoning the highest floors of the market).


    So, Kemper hit the market with something completely new, and genial. I believe the KPA user is a musician not looking for a selective, analytic approach based on a "block" logic, but fascinated by the profiling concept. Different tools for different tasks, as they use to say.
    We as musicians have to be clear with ourselves about what our needs and expectations are: there's currently nothing like a universal machine.
    I, for one, am leaning toward the sound fidelity and the easiness of use of the KPA.

  • I'm FRFR, if this is possible without compromising the full signal on the monitor out, why not

    "Music is enough for a lifetime, but a lifetime is not enough for music" Serghei Rachmaninoff


  • viabcroce, you are mixing up things here. Were are not talking about the amp influence on the cab profiles themselves but the "cab off" function not working as it should.


    Please, leave this thread a petition, not a discussion.

    tylerhb, are you a moderator? You're not, AFAIK.


    I'm sorry you're taking it bad, but I've joined this forum to discuss things as well as to learn more about the KPA. If your response implies I might be an Axe fanboy trying to stir the pot, you're completely off here. I don't think my post is OT at all, and I'll explain why.


    IMO, the reason why "a small part of the cab portion remains in the signal chain" is because there's nothing like a real, separate cab module that can be switched on and off. This is IMO inherent to the KPA design, and I've tried to explain why.
    If I'm correct, the petition has no sense.
    I can be wrong here, but the way I see it is that, when you switch cab off, the OS subtracts the generic amp model from the whole signal; and that's because these are the only arrays of data the KPA can detect and store.


    I don't know (yet) where the technical truth is, but I find surprising that some owner can be not interested in better understanding how this unit works and, TBH, can't understand your attitude here. I don't need to believe the KPA is the best, ultimate, unbeatable unit around in order to love it and wanting to own one.


    I really, really, really hope this forum is not destined to become intolerant like the Axe-Fx forum. We're still on time, guys :)


    Peace

  • I would love for this functionality as one of the reasons why I returned my first KPA was because I was going through poweramp+cab and turning off the cab did not have the desired result. I would like to have the choice of using a cab sometimes. However, I agree with viabcroce as to why this functionality will not happen.

  • If at all possible (and if my memory is correct CK did not say that it was not possible) this is a "must have" for me.


    But think about it, if all you know is the signal going into the amp and the signal coming out the cab, how can you possibly tell what contribution in the changes in distortion and eq came from just the cab and what came from the amp. Perhaps you can make some guesses or approximations based upon what you know of what a typical speaker and cab may do to a signal, but that would not seem to be exact enough for most of us. To be able to be exact sounds like magic.

  • Maybe Kemper could solve the problem like this:


    If they do come out with the SS Power Amp to be part of the Kemper (installed in the back), this could be used to "profile" the cabinet, if the SS power amp is linear enough. One would then use the integral Power Amp tp first profile the cabinet, then one would profile the whole signal chain and the Kemper could then substract the "cabinet" only profile.


    Bear in mind, that you would still get "coloration" from the mic and mic preamp, but if "profiles" of the freq response of the mics would be available then these too could be substracted.


    Would love to see this discussed by Christoph.


    Cheers,


    Dote

  • Sorry, you misunderstood me here. I opened up this thread just for one patircular reason: To know, who else needs this feature in the way i described it. Just a simple user count so to say. It was no criticism to your statement. If i present to Burkhard or christoph that maybe 50 users or more sign the petition for a particular feature, it will have more effect than just the normal discussion in the threads. Keep in mind that the guys at Kemper wont read each single discussion thread.

  • I hear you tylerhb, and I for one would love to see such a possibility to be implemented.
    I was trying to show how IMO this is not part of the design. Hope I'm wrong, but... :/


    Peace,

  • To clarify things a little bit: I meant not to change the profiling in the way that the amp (clean/distorted) has an effect on the cab profile, like in the discussion "clean vs. distorted amps for cab profiles" a few days ago.


    If you simply choose a DI profile which was profiled without cab portion and use the monitor out with "cab off" in combination with a poweramp and guitar cab you will hear the sound as it should be. If you then add a cab profile afterwards which should only affect the main outs that go the PA, you will hear how this has also an effect on the monitor out. That´s what i am talking about.


    Since the cab sound in this situation is evidently is not a part of the DI profile it means that the KPA uses some sort of "blending" here.


  • It's not intolerance...it's simple courtesy to your fellow man. Please exercise it so this thread stays on track.

  • Chill down guys, we are here to make music. I'm FRFR since ages, but I've tried the Kemper through the return of an amp, and when it sounds bad is just because the original amp is far too far away from the profiled one. If you take a marshall profile and run it through the return of a marshall head and its cab it sounds glorious. Same when you play around changing cabs: a twin through Till's 1960 06 sounds crap..
    Just like in real life.... ;)

    "Music is enough for a lifetime, but a lifetime is not enough for music" Serghei Rachmaninoff


  • I totally agree 100% on this. Consider my "signature" on this petition.


    This is the single biggest flaw in the KPA that prevents me from making it my #1 live rig.


    It would even be nice if there was a knob function to "restore" or even ADD punch/dynamics to the monitor output for those using it in such a manner.


    :thumbup:

  • To clarify things a little bit: I meant not to change the profiling in the way that the amp (clean/distorted) has an effect on the cab profile, like in the discussion "clean vs. distorted amps for cab profiles" a few days ago.


    If you simply choose a DI profile which was profiled without cab portion and use the monitor out with "cab off" in combination with a poweramp and guitar cab you will hear the sound as it should be. If you then add a cab profile afterwards which should only affect the main outs that go the PA, you will hear how this has also an effect on the monitor out. That´s what i am talking about.


    Since the cab sound in this situation is evidently is not a part of the DI profile it means that the KPA uses some sort of "blending" here.

    I didn't fully understand what you were talking about until you said this.. +1 This should be fixed asap