How much does the KPA color signal path?

    This is something I wasn't able to reference on the forums, I apologize if this has been discussed before.


    Although I have been using the KPA for some time, I don't have too much experience profiling. I've tested the water a bit at home, but this was more to get familiar with the process than to actually make some useable patches. I plan on going into a friends studio and profiling a few of my own amps, and just wanted to see if anyone has noticed if the KPA itself tonally colors the signal path significantly.


    More specifically... In this instance, I was micing up my Egnater Mod 50 to get some really basic "clean with edge" Americana type tones for a project I was working on. I ran just the SM57 in front of my amp directly into my Fireface UFX interface, and directly into my recording program (Cubase 7.5). After fiddling around a bit, I got a tone I liked and printed it to a wav file for a reference. Since I liked the sound, I naturally wanted to profile it. So, I put the KPA in line, ran it per the instructions in the manual, set levels etc. and went through the profiling process (without altering any EQ settings on amp or adjusting mic placement. I just adjusted the return level in KPA to match a similar profile). When comparing the Profile/Reference in this set up, they sounded acceptably similar. However, when I compared it to the previous mic sans KPA track...A WORLD of difference. The direct mic was clear and present, the tone through the Kemper in line sounded like it was running through a drive through speaker.


    I guess most people that profile are running through the Kemper from the get go, and dial in a sound they like perhaps compensating for any tonally anomalies the KPA might add to the equation. That, or very possibly, I'm doing something wrong. I know that everything in a signal path affects tone to a degree, but I thought this was pretty significant, and perhaps warranted a shout out to you profiling gurus that might know more than I. The way I am running it now, there is something seriously altering the tone between my guitar and the amp. Also, just as an aside, I am using all very high end cabling...Vertex, Vovox, so cables should not be an issue.


    I am including a very short mp3 so you can hear what I am talking about. The direct miced cabinet is first and the second clip is routed through the KPA.


    Thanks in advance for any input!


    KPA Color Test
    Mark Dannells

    Hey Mark,


    I'd strongly advise you to read the Profiling chapter on wikpa.org. There is a number of things to know, for example that Distorted Sens setting affects the Direct Out.
    Also, if you want a more realistic comparison between the amp and the profile you should switch to Browser mode...
    You'll also find a number of tricks & tips :)


    Last but not least, refining should anyway be taken into consideration after profiling


    HTH

    AHH! Again with Clean/Distorted sense! I've really got to get that end of my KPA-ing together. This is the second time I've had an issue with this somewhat enigmatic parameter. Yes, Gianfranco, I need to reference the wikpa.org again...It's a great resource, and I haven't checked it out in quite a while. I'll do some more research before I go clean sensing any credibility I have left out the forum window! :) Thanks for the reminder.


    Basically, what I want to know is...Theoretically, the KPA should have no more effect on your tone (when profiling...obviously not in standard use) when it is in line than any other high end digital processor. Is this somewhat accurate?


    Also, on a somewhat unrelated note for anyone that might be reading this...I just picked up a KMI Softstep 2, which I think is a really promising (and affordable) foot controller option for the Kemper. There are few little things that I have talked to them about in terms of functionality with the KPA (above and beyond that which is already available, which is still pretty cool) that if resolved, will make it a excellent controller choice. I'll post more as I get the information.

    I listened to your clip - and yes, I agree - like day and night.


    The second part is very dark compared to the first one.


    I did not notice any of this problems here.


    Be careful with the Vovox cables when using ground switches on the KPA - the Vovox cables have to be used in the right direction - and I found this leads to problems sometimes when using a lot of them in the chain.

    (All trademarks are trademarks of their respective owners, which are in no way associated or affiliated with soundside.de)


    Great Profiles --> soundside.de

    Quote from MarkD

    AHH! Again with Clean/Distorted sense! I've really got to get that end of my KPA-ing together. This is the second time I've had an issue with this somewhat enigmatic parameter. Yes, Gianfranco, I need to reference the wikpa.org again...It's a great resource, and I haven't checked it out in quite a while. I'll do some more research before I go clean sensing any credibility I have left out the forum window! :)


    LOL


    My note was about Dist Sens, not Clean Sens! The latter doest'n affect the profiling process at all :)
    Also, be sure to follow what I hinted at in my previous post, it might do all the difference you're mentioning.


    On a side note, it might happen that a profile comes out bad. Usually next time you try it's ok, unless the amp belongs to the small circle of the not-profileable amps.
    I think that just trying again taking care of the above and carefully checking the levels in the path might lead to you better results :)



    I doubt that a quarter of a dB @30 Hz and the added content at 18 kHz is what we're hearing here :)

    Thanks, all...I was 99.999999999(etc) sure I was running something wrong, but I thought the coloration question was interesting one to pose for the benefit of both current users and those gathering information before taking the plunge. The Har Bal screenshots are great, raen. I use that program quite often as well. I am well aware of the way AD/DA converters can alter things sonically, but I had no idea that it would be THAT close according to the analysis. Impressive.


    You mention with stomps, stack and effects off. You took a signal from the direct out, right? The direct out isn't affected by the KPA's processing at all, so it wouldn't matter if they were on or off!
    Cheers,
    Sam

    Quote from sambrox

    m the dir


    Quote from sambrox

    You mention with stomps, stack and effects off. You took a signal from the direct out, right? The direct out isn't affected by the KPA's processing at all, so it wouldn't matter if they were on or off!
    Cheers,
    Sam


    The "blue" signal is recorded from the "MAIN OUTPUT" of the Kemper, because i was interested, how "colorful" is electronic circuit and AD-DA converters of the Kemper. That was target of my test.

    Quote from raen

    Well, it's actually more, than a quarter of a dB @30 Hz. You must multiply it with 10. However, it is clear that we did not need that sub-bass anyway



    OK, I missed that x10 dB thing. That makes it a bit more interesting. But you're right, even with downtuned guitars that might not be the end of the world, unless you're Meshuggah. But 8-stringers may feel a difference, to be fair. I don't know what to think about the 18kHz+ thing though. I would imagine maybe that gets rolled off internally anyway (in the stack section etc.)?

    About the 18kHz+ thing: When I first listened to the KPA through my active CLR I was confused about these very high fequencies. I tried to dial them out with an EQ and landed @ approx. 20kHz (can't remember the exact frequency). Now I know that this wasn't just imagination, thanks. Nowadays I don't care about these very high frequencies anymore because I'm simply used to them.

    I could have farted and it would have sounded good! (Brian Johnson)

    Edited once, last by Kempermaniac ().

    Well, that graph was made with no amp, eq, stomps, cabinets in the chain - i.e. just running a signal through WITHOUT any "kemper stuff" on the signal. The curve would look very different. Don't know if it would match a regular cab with regards to those high frequencies, but shooting in the blind here: the CLR is like a wedge, isn't it? So it points more toward your head than your feet, unlike a guitar cab? If so, that could be it. I've heard lots of sound guys complain that people EQ their amps to sound good when they're not pointed directly at the ear; whereas the mic (and the audience, if the stage is raised) listen at speaker height, making for a very shrill experience sometimes :)

    The recording is simply dull, very dull.
    Please check what could be the cause.
    Is it the microphone plugged directly to the profiler?
    Had the channel where the mic was plugged before a different EQ setting?


    Some myths to fight:
    Distorted Sense should be zero in any case, exept for the intended purpose.
    Switching to browse mode does not make the A/B comparison better, it's the opposite.
    No human being can hear signals at 18 kHz in vicinity of signals that are more than 40 dB louder.