How well does kemper profile multiple distorting stages? Preamp + power amp clipping DI test

  • Dear all,


    Here is a test I did today. I figured due to the nature of the topic you may be interested. You can hear how profiling accuracy degenerates when the power amp is pushed hard. I structured the test in a way to make this comparison easy to follow for the listener. Just use fine monitoring. In the lack of that, of course you may not hear much of a difference.


    But the difference does matter to me (I am sure many wont care nonetheless, CK for sure does). I would say the tonal difference translates to quite a big one in feel when the power amp pushed this way. I suspect this happens to quite a few -- profiling an amp at the point where power amp distorts and loosing accuracy because of it (maybe not even realizing that the power stage is clipping).


    So this is one thing to watch out for. Finding the stage where the power amp does not confuse kemper is essential to proper profiling. It's not always as simple, amps are not all the same, which is why proper attention is worth it if you wanna get the best out of your profiles. I would encourage only slightly less volume from the amp, a bit less, and less, till you reach the point when profiling works as well as it can (that is if you like tones with power amp higher than 2/10!).


    Yes, I know the "dual stages distorting" is "in the manual"; no, I don't have to go read it; no, I don't think kemper sucks, blah blah blah :)



    Cheerios

  • Impressively close, I don't know that anyone would dispute that, but not exact.


    Some people actually prefer the profile to the amp because it can add a compression which feels "tighter". Even in many comparisons people can hear a difference, they just may not be able to say which is obviously the KPA and which is obviously the amp. The most famous comparison was the Anderton's video, which was also assisted by being played through the same Victory cab. Regardless, the differences were noticed and voiced, they just didn't know which was which. Chapman, if I recall correctly, preferred the KPA tone to the amp due to the "tightening" that occurs in most of the cases.

  • Impressively close, I don't know that anyone would dispute that, but not exact.


    Some people actually prefer the profile to the amp because it can add a compression which feels "tighter". Even in many comparisons people can hear a difference, they just may not be able to say which is obviously the KPA and which is obviously the amp. The most famous comparison was the Anderton's video, which was also assisted by being played through the same Victory cab. Regardless, the differences were noticed and voiced, they just didn't know which was which. Chapman, if I recall correctly, preferred the KPA tone to the amp due to the "tightening" that occurs in most of the cases.

    I always thought that was a strange comparison, because they fiddled a lot with the profile after creating it - you can see it in the video. Supposedly to make it sound more like the amp, but...

  • In the low power amp volume comparisons, it sounds like the Kemper profile is lacking something in the low end. I've found that this can happen during refining sometimes, but can also be remedied by refining in a specific way. Michael Wagener talked about certain tricks to rectify this, if a profile is lacking pre refining. The higher power amp volume comparisons are of course totally f***ed, haha!

  • Refining was quite extensive in this case (not in time but in terms of trying to get it as close as possible). Wagener’s tip is playing the opposite of what is missing from the profile — the exact opposite of what CK suggests, in fact. So there is conflicting info between maker of unit and one of the biggest producers using it. Wagener also does some trickery with compensating using eq somehow, but as far as I know he has not documented this as it’s highly amp-tone specific, which is my experience as well, probably doing similar stuff.


    Without refining the bass/mid character was more off than the resulting profiles in this test. While refining helped, as it usually does, this is as close as I could get it... which is my experience profiling most if not all crunch-gains-metal tones; once a specific “threshold” is reached the tones are super close, but the minor differences are fairly consistent nonetheless. Never heard a proper test show otherwise. Worth noting is that string height (even with perfect frets) and pickup can also play a role in how much differences show. That is just in my experience.


    But anyway I’m not trying to open a can of worms or a thread that we know will not be productive anyway :)


    The test is more about profiling accuracy with single distorting stage vs 2 stages and just to show that 1) Kemper can get pretty close when only one stage distorts and 2) it’s something to be careful with when profiling. I’ve played plenty of shared profiles where the above happens but people don’t realize it (not even the person doing the profiling; not blaming anyone, easy to happen, has happened to me too). The result is often a pretty weird feeling and sounding profile. Some have liked these profiles too though and still don’t think the difference matters then... which is again totally fine, just something to keep in mind for those profiling amps.


    Cheerios, fine weekend to you guys!

  • Impressively close, I don't know that anyone would dispute that, but not exact.


    Some people actually prefer the profile to the amp because it can add a compression which feels "tighter". Even in many comparisons people can hear a difference, they just may not be able to say which is obviously the KPA and which is obviously the amp. The most famous comparison was the Anderton's video, which was also assisted by being played through the same Victory cab. Regardless, the differences were noticed and voiced, they just didn't know which was which. Chapman, if I recall correctly, preferred the KPA tone to the amp due to the "tightening" that occurs in most of the cases.

    I like Chappers videos but that comparison, imho, was far from a proper test. Not that it was intended to be so; their videos are at least half “for fun”, which is great in its own right. I wouldn’t have been surprised though if they’d be saying that real amp is way better, thinking kpa is not as accurate as it is, and the cause of them thinking so being them confusing profiling accuracy with using power stage vs solid state stage... plenty of times, I think, their thinking has been questionable in that fashion... not that chappers didn’t say kemper was “tighter”, which would probably been correct anyway.


    And that’s not to imply I don’t make mistakes with thinking A or B, not by any means.

  • Impressively close, I don't know that anyone would dispute that, but not exact.


    Some people actually prefer the profile to the amp because it can add a compression which feels "tighter". Even in many comparisons people can hear a difference, they just may not be able to say which is obviously the KPA and which is obviously the amp. The most famous comparison was the Anderton's video, which was also assisted by being played through the same Victory cab. Regardless, the differences were noticed and voiced, they just didn't know which was which. Chapman, if I recall correctly, preferred the KPA tone to the amp due to the "tightening" that occurs in most of the cases.

    I was a tube amp snob for a long time, until about 2 months ago, when my torn rotator just couldn't take hauling my amps around to gigs anymore. I tried the Helix first. Loved the UI, hated the time it took to get a decent sound out of if. And hated even more that my amp tweaks couldn't be saved and recalled for a different patch. I know you can copy/paste amp profiles, but that was a deal breaker for me. Plus, I have a great pedalboard that I love. So next was the Kemper. It's taken about a month to really understand each of the parameters and what they do, but it's much easier to get a great tone out it. I'm using no/low-gain tones as I'm running OD's in front of the Kemper, and every week, so far, our FOH engineer has commented on how good it sounds.


    I'm sure if I listened to this test through my studio monitors and not the cheap Logitech speakers I have currently connected to my computer (I'm remodeling my music room for a dedicated recording/monitoring space), I could hear the minute differences you're talking about. But through the Logitechs, the first amp clip, and the first Kemper clip are identical to my ears.

  • I was a tube amp snob for a long time, until about 2 months ago, when my torn rotator just couldn't take hauling my amps around to gigs anymore. I tried the Helix first. Loved the UI, hated the time it took to get a decent sound out of if. And hated even more that my amp tweaks couldn't be saved and recalled for a different patch. I know you can copy/paste amp profiles, but that was a deal breaker for me. Plus, I have a great pedalboard that I love. So next was the Kemper. It's taken about a month to really understand each of the parameters and what they do, but it's much easier to get a great tone out it. I'm using no/low-gain tones as I'm running OD's in front of the Kemper, and every week, so far, our FOH engineer has commented on how good it sounds.
    I'm sure if I listened to this test through my studio monitors and not the cheap Logitech speakers I have currently connected to my computer (I'm remodeling my music room for a dedicated recording/monitoring space), I could hear the minute differences you're talking about. But through the Logitechs, the first amp clip, and the first Kemper clip are identical to my ears.

    I think there's "snobbery" on both sides when it comes to the whole tubes vs digital subject. Some digital modeler users will try to diminish anyone's view that he can hear differences and that these matter. It must be due to him being 1) arrogant 2) a snob 3) would never be able to tell the difference in a blind test and it's all mental bias. On the other hand, you are crazy to think a modeler can replicate any tube amp well enough.


    I've often felt as if standing between these two extremes. That said I don't think my own evaluation of "whether differences matter" is even important. I rarely say much about that even if it's an interesting topic as well. I just do the tests, most often, and people can make up their own minds.


    Some have listened to this test and told me they don't think single stage distorting vs two stages is all that different in regard to profiling accuracy, for example. Others say there's a big difference. I think there's an important difference, but my view about accuracy with single distorting stages is similar to what it was eons ago.


    And it's great you are enjoying using kemper or any device for that matter :)

  • Of course the relevant question is: do you want both preamp and power amp gain to begin with?


    I think very few would prefer the amp tone here with the power amp at 8/10.


    The type of playing matters, of course, as does the amp, the interaction between preamp and power amp, how you dial in the EQ when power stage is cranked vs mellow (No such changes here, As the aim was just to test profiling accuracy).


    On that end with proper settings i do have cases where, for my taste, a mix of preamp and power amp distortion sounds best. But the aren't that common, to be fair.


    I agree with the notion that power amp distortion is often exaggerated in terms of importance.

  • Thanks for taking the time to do this.I'm curious if you tried to use the definition or clarity and maybe a combination of both to reduce the differences when you used more power amp . I notice many profiles from commercial sellers seem to add more definition.


    I remember that two years ago, there was still a small issue with differences in the low end and the kemper was slightly looser and not as tight as the real amp when profiling, so now it could be possible that to fix that, the profile is now tighter than the amp. Also I would consider playing with the tube shape, in this case I would guess that lowering it might get you closer to the amp.

    I didn't change any settings post profiling in the test, no. Did it later and couldn't get closer to amp when it comes to dual stages distorting. Adding defintion kind of exaggerated some mids differences. But I am not sure about all this in this case, have to do another test where this is the goal, and play with tube shape as well.


    About the "loose low end" fix, yea, I think that could be the case. I tried to track down a kemper with old frimware (my first kemper actually) before to test this but the guy had updated the firmware like a week before!


    Cheers

  • would think the current solution with Kemper as is for this type of situation is to capture the amp with Power amp and minimal Preamp gain (where you believe you would get more accurate results), then later use the Kemper Gain knob to add the preamp gain. or pure boost, I would be curious if you would get more accurate results that way. In this situation if you profile that amp at 8/10 Power amp and minimal Preamp gain then for the resulting profile after refining, increase the gain on the Kemper as wells as the amp and compare.

    I think this is a very good/productive idea for a test, yes. I'll be on it.

  • Thanks DIMI, something tells me ti could also be further away depending on how different the KPA preamp gain and the actual amp preamp gain but who knows it might work for some amps.

    It will be quite amp dependent because preamp at higher values will affect power amp differently when higher, and even just on its own can sound different anyway, apart from gain. Depends on the preamp, power amp.. I did do the test though. Will upload in a while.

  • Kemper keeps the character of the tone similar even if you increase the gain in kpa. It can be bad in this case, if you are trying to profile dual distorting stages in this manner and then compensating by adding more Kpa gain. But it is good if you prefer the tone of the amp preamp lower, but with more distortion. It's possible, depending on the case, to end up with with a better high gain tone than the real amp that way. Set preamp where the amp sounds best, which may not Have enough gain for you, then Just add more gain on kemper.