Power amp

    @ viabr :) Yes i know about the PA (asses), but I personally never heard or seen the Kpa in concerts jet. Only through my own experience, youtube, and recordings.


    Maybe this two video links to redponycar describe what I experienced. Maybe it is not a realistic or naïve compare, or just coincidence but it shows the same difference in sound what I hear when switching between transistor or tube


    Jet city jca22H (tube)


    http://www.youtube.com/watch?v…=UUd5eHahzTaLgTv1ypHTEehg


    Peavy PV-260 (trans)


    http://www.youtube.com/watch?v…=UUd5eHahzTaLgTv1ypHTEehg

    When you use an FRFR system you get full range speakers outputting - amp modeller with simulated cab AND simulated microphone. So immediately right there you have an extra variable that you do NOT have when playing through a classic half-stack setup.


    When you play through a poweramp and guitar cab you get frequency limited speakers outputting - amp head, no simulated cab, and no simulated microphone. So even if you use a digital modeller this is still closer to a traditional rig.


    I strongly believe it has nothing to do with people expecting an off-axis sound, and everything to do with that extra microphone colouration. Which you cannot get rid of with the Kemper. For this reason, if you want a more traditional experience, I don't think the Kemper is going to do it for you. You'd be better off with an Axe FX, Pod HD, or perhaps even a Blackstar ID amp.


    I think there is a lot of conflation about what people are actually looking for. Some people want the studio sound on stage, going to monitors so that they can hear what the audience hears. Other people want the ultimate in flexibility whilst retaining as much of the traditional experience as possible. For live performance, I am more of the later.


    I dislike it when people try to push FRFR at me. It isn't the same. It'll never be the same. The differences between each approach are fundamental in the designs. The Kemper *CAN* work really well in a live situation, but you have to mould yourself into its design, not the other way around.


    Don't get me wrong, I am absolutely loving my Kemper. As I have said, I prefer it to my Axe FX. But if you're in a rock band and you want your trousers to flap on stage when you stand next to you Marshall 4x12, and you want the musical feedback that sounds soooooo good with Vintage 30's or T75's (for example!) ... then FRFR isn't for you - imho.


    And once you say that, the FRFR crowd start saying things like "well you must not care about your audience" or "who cares.. the audience cannot tell anyway" .... infuriating. I wish people would just accept that all our needs are different.


    At the end of the day, when I can truly feel connected to my instrument and my amplifier, I play better, the band sounds better, and the audience gets a certain experience that you can't get any other way.


    Remember... not all of us are playing huge stages or quiet little restaurants and not all of us gig regularly. Some of us (like me!) play sweaty little bars and pubs with a maximum capacity of 150, where the PA's are very poor quality and where it's actually *better* to turn your amp up loud enough to fill the room.


    Again... all imho.

    Quote from drew_fx

    When you use an FRFR system you get full range speakers outputting - amp modeller with simulated cab AND simulated microphone. So immediately right there you have an extra variable that you do NOT have when playing through a classic half-stack setup.


    When you play through a poweramp and guitar cab you get frequency limited speakers outputting - amp head, no simulated cab, and no simulated microphone. So even if you use a digital modeller this is still closer to a traditional rig.


    I strongly believe it has nothing to do with people expecting an off-axis sound, and everything to do with that extra microphone colouration. Which you cannot get rid of with the Kemper.


    Well, I'm not sure I'd agree with this. In a profile or an IR the mic is not simulated, it rather works like a filter. This is not just splitting hair, since you're not limited by software.


    If you use a calibrated (measure-A) mic, for example, there's practically no colouration from the mic (FRFR, this time for real). Getting an IR that sounds like the amp is possible, like Jay Mitchell has explained.


    Also, when it comes to linear cabs Vs. guitar cabs, the difference has to be taken care of at model/profile level: it's up to the device to send a linear cab a signal which doesn't contain anything unrelated to how a guitar amp/cab sounds. You can't blame the microscope because you see the viruses, so to speak.
    As the Man Himself says, if you don't like what comes out of your linear cab, you don't like what comes out of your device :)

    Quote from drew_fx


    I strongly believe it has nothing to do with people expecting an off-axis sound, and everything to do with that extra microphone colouration. Which you cannot get rid of with the Kemper. For this reason, if you want a more traditional experience, I don't think the Kemper is going to do it for you. You'd be better off with an Axe FX, Pod HD, or perhaps even a Blackstar ID amp.


    Well, no. ;)
    Like CK himself has stated several times, it's actually very easy: if you want a traditional experience, switch off the cab in your profiler and play with a traditional poweramp/setup.

    Quote from Ingolf

    Well, no. ;)
    Like CK himself has stated several times, it's actually very easy: if you want a traditional experience, switch off the cab in your profiler and play with a traditional poweramp/setup.


    Um... I have tried that and it quite simply does not work. Disabling the cab does not fully disable the tonal effects picked up when profiling. That's the whole reason for direct profiles in the first place. But not everyone has the capabilities of doing that.


    Listen, I love the Kemper. But it isn't very good for this solution - playing through a poweramp and a real cab - it needs improvement in this area. End of story.

    Quote from viabcroce

    Well, I'm not sure I'd agree with this. In a profile or an IR the mic is not simulated, it rather works like a filter. This is not just splitting hair, since you're not limited by software.


    If you use a calibrated (measure-A) mic, for example, there's practically no colouration from the mic (FRFR, this time for real). Getting an IR that sounds like the amp is possible, like Jay Mitchell has explained.


    Also, when it comes to linear cabs Vs. guitar cabs, the difference has to be taken care of at model/profile level: it's up to the device to send a linear cab a signal which doesn't contain anything unrelated to how a guitar amp/cab sounds. You can't blame the microscope because you see the viruses, so to speak.
    As the Man Himself says, if you don't like what comes out of your linear cab, you don't like what comes out of your device :)

    Whether the microphone is simulated or not, it affects the tone. With a real microphone you have diaphragmatic distortion which can add saturation, you've got the frequency response of the microphone, as well as the impedance of cables, and any extra colouration of your preamp too. All these things affect the tone to some degree. Even with a calibrated microphone you have to bear it all in mind, because they are *not* full range frequency microphones, they're just flatter than most others - source: http://realtraps.com/art_microphones.htm


    But even then, lets say it were true... you're still getting a certain picture of the amp+cab setup depending on the position of the microphone. So you're not going to be able to capture a full picture of the amp with that setup. This is necessarily true and is the chief difference between the Kemper and other digital solutions - the Kemper captures the whole chain in situ, and does not seek to build a chain from the ground up. What this means is you cannot fully separate any of it. You can compensate, sure. But you cannot do a 100% nullification separation.


    BTW, you slightly contradict yourself in that you say the microphone isn't simulated, then you say it works like a filter... which is simulated in the Kemper. So yes... it is simulated.


    Not a diss against the Kemper, as I've said... I love it!

    You can test what I'm saying by doing this - profile an amp with its bass control fully cranked, its mids and treble fulled reduced, and the presence reduced. Use a cab with speakers that produce extremely bright frequencies, say... Celestion Vintage Century's. Use an SM58 with the filter cap removed, and put it up against the speaker at the edge. Your profile will most likely be completely bass heavy and sound utterly bad ;)


    Now in the Kemper, save the cab out as a cab preset. Change the rig to another amp, one that was profiled with reasonably neutral or clear settings. Now change the cab to the preset you just saved. My guess (and it is a guess, because I've not actually done this!) is that it will now sound ridiculously bass heavy... because the cab has elements of the original amp in it still. This will work vice-versa as well I think.


    Correct me if I'm wrong Christophe ;)

    Playing a tube amp or a KPA with FRFR are two different things.


    I use the KPA for recording and big venue-tours with in-ears (no amps on stage), for smaller clubs -when I'm standing next to the amp- I still prefer tube combos and pedals. It's more about the "feel" and interaction between guitar an amp. Just listen to Carlos Santana, then you know what I mean, he couldn't get his tone (harmonic feedbacks ect.) with a FRFR-system. I also don't need 50 amps in a box for playing small clubs, I like to keep it simple. ;)


    You can't get the pure sound of a Fender Blackface with a FRFR-system, maybe you can get close to it, but the speakers always will play a big role, too. Nevertheless the KPA is the perfect tool for anything else. ;)

    ------------------------------------------------------------------------------------
    first name: Guenter / family name: Haas / www.guenterhaas.de

    Quote from guenterhaas

    Playing a tube amp or a KPA with FRFR are two different things.


    I use the KPA for recording and big venue-tours with in-ears (no amps on stage), for smaller clubs -when I'm standing next to the amp- I still prefer tube combos and pedals. It's more about the "feel" and interaction between guitar an amp. Just listen to Carlos Santana, then you know what I mean, he couldn't get his tone (harmonic feedbacks ect.) with a FRFR-system. I also don't need 50 amps in a box for playing small clubs, I like to keep it simple. ;)


    You can't get the pure sound of a Fender Blackface with a FRFR-system, maybe you can get close to it, but the speakers always will play a big role, too. Nevertheless the KPA is the perfect tool for anything else. ;)


    Absolutely agree. I am loving my Kemper for recording. I don't think I would use it live though.

    Quote from drew_fx

    Whether the microphone is simulated or not, it affects the tone. With a real microphone you have diaphragmatic distortion which can add saturation, you've got the frequency response of the microphone, as well as the impedance of cables, and any extra colouration of your preamp too. All these things affect the tone to some degree. Even with a calibrated microphone you have to bear it all in mind, because they are *not* full range frequency microphones, they're just flatter than most others - source: http://realtraps.com/art_microphones.htm


    Now this seems to me splitting hair! Nothing is really linear or full range in the known Universe, but something can be linear with respect to human ability to distinguish things. The key point here is "orders of magnitude".
    So if my guitar and amp sound different when I use two different signal cables, which of the two is the "real", "unaffected" sound?
    Again: variations in the mains' voltage change the way tubes work: are you aware of the different voltage levels in your room at the different hours of the day? Which one is you amp's "real" sound?


    As for measurement mics, what matters most is not the mic's linearity but its calibration: this means you know the mic's amplitude response and its variations, and correct it so that its linearity falls below the threshold you have chosen.


    Quote from drew_fx

    But even then, lets say it were true... you're still getting a certain picture of the amp+cab setup depending on the position of the microphone. So you're not going to be able to capture a full picture of the amp with that setup.


    Wherever you and the amp are in a room, you will hear it differently. Which is your amp's real sound? The one you perceive standing in front of it, sitting in front of it, standing by its side?
    IOW, the amp's sound will always depend on both the amp's and the listener's position. Again, which one is the real sound?
    And what if I put my amp on a stand or on the ground? Which sound is the real one?


    Rest assured that moving your amp in a different room changes the sound orders of magnitude more than a bad-calibrated test mic or a hi-end mic pre (I strongly doubt you can perceive +1.6 dB @ 17.250 kHz).


    Quote from drew_fx

    BTW, you slightly contradict yourself in that you say the microphone isn't simulated, then you say it works like a filter... which is simulated in the Kemper. So yes... it is simulated.


    No, I certainly do not. The Profiler doesn't simulate any mic. It receives a sound, which had already been filtered by a mic. These are two completely different things. If what you wrote was true, we should also say that if I put a blanket on the loudspeaker ad take a profile, then the Profiler is simulating the blanket. Or, if you will, when you hear an amp sounding differently because you moved it into a different room, your ears/brain are "simulating the room".


    Quote from drew_fx

    Not a diss against the Kemper, as I've said... I love it!


    No problem, I'm not discussing with you in order to defend the product, nor I feel the need to show that what I use is the best! Please do not read in my words more than what I'm just saying :)

    For live use with tube power amp & cab, I run preamplifier profiles from the monitor out.The KPA does an excellent job for this,the sound is "warm" and "breathes" almost the same way the real amp does it.
    However for full profiles with the cab sim off I prefer transistor power amps. So depending the amp I have or provided as backline on stage, I use the appropriate. profile.

    This is all very philosophical! :)


    I'm not talking about making a distinction between "real" and "unreal" that isn't the point I'm making. I'm making a point about the number of filters in a system and the quality of the ability to remove those filters. I take your point about moving around the room... which is the real amp sound... your point is that the room is also acting like a filter. But it doesn't matter, because in that situation there is no microphone acting like a filter. It doesn't matter how accurate the Kemper is... there will always be an extra filter affecting the sound. And it's this extra filter that makes it unsuitable for putting through a guitar poweramp and cab.


    imho :)

    Quote from drew_fx


    Um... I have tried that and it quite simply does not work. Disabling the cab does not fully disable the tonal effects picked up when profiling. That's the whole reason for direct profiles in the first place. But not everyone has the capabilities of doing that.


    Listen, I love the Kemper. But it isn't very good for this solution - playing through a poweramp and a real cab - it needs improvement in this area. End of story.


    You could always profile your choice of amplifier with said cabinet. I'd love to see some A/B comparisons of a profiled amp with cab and then the Kemper running through the same cab. It would shed some light on the abilities/limitations of the Kemper Profiler.


    Also, different doesn't necessarily mean worse. I think there are a lot of people that would agree you can get your pants to flap using the Kemper power amp with a 4x12. AFAIK, there are also FRFR giant size cabinets.


    I'm looking forward to what Mr CK comes up with in this area, since he has indicated that a means of better separation of cab and amplifier in profiles is in his list of "to do" things. When such an update comes is, of course, anybody's guess.


    As far as a microphone acting like an additional filter, I'd have to agree, the choice of microphone and its characteristics is likely to have an impact on the eventual profile. But as I said, some A/B comparisons would be in order before I can say it is less desirable.

    Quote from drew_fx

    I take your point about moving around the room... which is the real amp sound... your point is that the room is also acting like a filter. But it doesn't matter, because in that situation there is no microphone acting like a filter. It doesn't matter how accurate the Kemper is... there will always be an extra filter affecting the sound. And it's this extra filter that makes it unsuitable for putting through a guitar poweramp and cab.


    IOW, you believe that it doesn't matter whether your amp is placed in a corner or in the middle of the room, it always sounds "like your amp"; while you'd be "disturbed" by a calibrated mic driving a high-grade preamp, which introduces a "filter", as you call it, orders of magnitude smaller than the room. Fair enough :D


    Jay Mitchell says that his IRs sound exactly like his cabs. If you're interested in deepening the matter, do a search on TGP. He's explained the procedure to get (and reproduce) IRs that are undistinguishable from the cabs.


    :)

    Quote from viabcroce


    IOW, you believe that it doesn't matter whether your amp is placed in a corner or in the middle of the room, it always sounds "like your amp";


    No, that isn't what I believe at all. Where the amp is placed in the room makes a big difference to the tone. The materials in the room make a big difference to the tone. The table the cab stands on makes some difference to the tone. If it's on the floor instead of being on a table, that also makes a big difference.


    Quote

    while you'd be "disturbed" by a calibrated mic driving a high-grade preamp, which introduces a "filter", as you call it, orders of magnitude smaller than the room. Fair enough :D


    Again, this also isn't true. I wouldn't be disturbed. It is what it is. But that is *not* the sound I want. I want the sound of a real speaker cabinet, and not a FRFR solution.


    Quote

    Jay Mitchell says that his IRs sound exactly like his cabs. If you're interested in deepening the matter, do a search on TGP. He's explained the procedure to get (and reproduce) IRs that are undistinguishable from the cabs.


    To be frank, I don't really care what Jay Mitchell thinks. FRFR cabs and guitar cabs are not the same. They will never be the same regardless of how you capture the IR's. FRFR cabs have crossovers that affect the frequency response and phase of the speakers. Guitar speakers do not. They shape the sound in a universally-accepted pleasing way. A transparent hyper-profiled IR will not capture that effect.


    You just have to accept that an FRFR system cannot replace a traditional guitar cab. They're different conceptually and fundamentally, and each has its own compromises. It just so happens that I am more comfortable with guitar cabs in a live setting, for recording I prefer to monitor what the microphone picks up. But for me, there is something really primal, magical, and unique about a cranked amp and a 4x12 cabinet on a stage. Which is why I prefer the traditional method for live use. It's a feel thing, and is something that the OP talked about too - he wasn't unhappy with the "sound" of FRFR, but he was unhappy with the feeling. I sympathize with that.


    For reference, when we play live I usually ask the soundman to mute or turn my guitar right down in the monitors. Because it ruins the gig for me. I only need kick drum in my monitor. I get all my stage tone from the amp behind me, and I often turn around and move around the stage to get musical feedback.


    Anyway, we're just sorta going round in circles now. I'll finish with this - I hope Kemper do eventually improve the separation of the amp from the cab and microphone, so that for live use you can go through a poweramp and guitar cab. The Axe FX is a bit better at this right now.