Be aware of the digital sonic artifacts (aliasing) in your KPA!

i vote to use the calculation power for less aliasing, its more important to me than features to just have a solid core amp tone,
I am surprised that the processor will be running out of headroom , for almost 2000 us dollars seems like a top of the line processor or even 2 could have been implemented. but if i had to choose i would choose less aliasing . The tone is awesome of the kemper and effects can be added after if we have to

hopefully there wont be a kemper 2 with a faster processor anytime soon though , ID hate to make this one obsolete and have to buy the newer faster one already .

Quote from Jimmyno

Only for fully grown man

By the way, i have no aliasing issue too, since I don't use too much gain.
I like the idea of the anti-aliasing filter: i wonder if you might implement it as a stompbox, in order to "suck" enough DSP to reduce the issue for people who feel uncomfortable. Just like a DSP booster, if I have explained my idea.

I don't think it can be fixed that way. It is not a matter of filtering frequencies but more like generating them properly. If their code is good enough probably the only thing they need to do is increase the internal oversampling. Maybe that's why CK said it would only take him 3 seconds to fix it.

I also vote for increasing the frequency. The strength of the KPA is the core amp tones.

Quote from MadH

I don't think it can be fixed that way. It is not a matter of filtering frequencies but more like generating them properly. If their code is good enough probably the only thing they need to do is increase the internal oversampling. Maybe that's why CK said it would only take him 3 seconds to fix it.

Well, I'm a total dumb about it, so i honestly don't know how it works.
The only thing I know is that some simulators (like Revalver or Lepou plugins, which are very good in my opinion) have a switch to increase the oversampling. My idea is basically to create a "fake" stomp box which occupies a stomp slot and works like an oversampling switch.
I don't know if it is possible on the KPA, of course.

I think it's worth using up a little bit of DSP juice to improve the "aliasing" for those users who have to use "artificial test tones" that cause the aliasing.

Quote from ckemper

However, it takes only three seconds for me to speed up our algorithms for the next firmware.
But this would eat up some of the headroom for the future.
Still we don't know how much headroom we will use in the future.

What do you think?

CK

I vote Yes-do it, and make this unit the best "Amp" it can be.
After all, it is called "The Kemper Profiling Amplifier"
Not the Kemper Effects Processor.
I can always use my stomp boxes for whatever won't fit in the KPA, just as I do now, and have been doing for the last 40yrs.
Make the core amp sounds in this box even more untouchable than they already are, and put an end to this.

Quote from imall41

Make the core amp sounds in this box even more untouchable than they already are, and put an end to this.

you had me at hello

let's do this!

I have aliasing only in some high gain profiles,and I notice it when I play alone, not playing in a band or in the mix. So for me isn't a big issue, but for all the people that's important, there should be an option (a soft button maybe) to choose between "high speed" = less aliasing and "normal speed"= normal aliasing.

Quote from grorig

I have aliasing only in some high gain profiles,and I notice it when I play alone, not playing in a band or in the mix. So for me isn't a big issue, but for all the people that's important, there should be an option (a soft button maybe) to choose between "high speed" = less aliasing and "normal speed"= normal aliasing.

That's my vote as well. Of course when (if) Kemper includes harmonizers/pitch shifters/etc which can't be used when the unit is set to high speed due to running out of juice, then your have another 50 post thread of people complaining. Can't please all the people all the time...

Quote from Jimmyno

Well, I'm a total dumb about it, so i honestly don't know how it works.
The only thing I know is that some simulators (like Revalver or Lepou plugins, which are very good in my opinion) have a switch to increase the oversampling. My idea is basically to create a "fake" stomp box which occupies a stomp slot and works like an oversampling switch.
I don't know if it is possible on the KPA, of course.

I was referring to what you said about ''antialiasing filter". The switch to increase oversampling is something different. That's a good idea and common practice for plugins since they are used in computers probably in concurrence with other plugins and softwares, so it make sense to have some control over the resources the plugin is using. I don't think is a good idea for a closed system like the KPA. It would make things more complicated for the users and probably for the development because they will need to take this into consideration for anything they do.

Quote from grorig

I have aliasing only in some high gain profiles,and I notice it when I play alone, not playing in a band or in the mix. So for me isn't a big issue, but for all the people that's important, there should be an option (a soft button maybe) to choose between "high speed" = less aliasing and "normal speed"= normal aliasing.

I'm for this option, even though I have never experienced any issues.

If some processing headroom is lost, how about using the empty space, in the rear of the KPA, for an effects processing daughter board add-on?

Quote from Dlaut

I love that idea!!!

I would choose that over an add on power amp module since I use the kemper only for recording through a DAW and powered monitors

I'm for this option, even though I have never experienced any issues.

If some processing headroom is lost, how about using the empty space, in the rear of the KPA, for an effects processing daughter board add-on?

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I say fix the aliasing. I don't know what kinds of extra effects are planned but I think aliasing comes first.

I'll throw in my lot with the less aliasing less features folks. Of course a soft switch would be optimal so people could choose what they want.

OK, what about this compromise? Add a "high res" mode/option that uses the processing to fix aliasing when dealing with highly compressed or distorted tones on the amp or settings. That way you don't have to add any funky logic to try and work out when to engage, and users can opt between more FX (where amp tone quality doesn't matter as much) or more pure amp tone (where it does).

Throw in a DSP usage fuel gauge page in the rig settings (or always displayed while adding/changing FX and amp settings) and everyone should get what they want.

I do have to admit though I'm surprised that the KPA doesn't have more surplus DSP power at it's current price point, but maybe the profiling amp sim is a very heavy algorithm, if so is there any chance of optimizing this further to free up the necessary cycles? Us guitarists can be a pretty demanding lot I'm afraid.

Quote from Per

OK, what about this compromise? Add a "high res" mode/option that uses the processing to fix aliasing when dealing with highly compressed or distorted tones on the amp or settings. That way you don't have to add any funky logic to try and work out when to engage, and users can opt between more FX (where amp tone quality doesn't matter as much) or more pure amp tone (where it does).

Throw in a DSP usage fuel gauge page in the rig settings (or always displayed while adding/changing FX and amp settings) and everyone should get what they want.

+1
Some very good ideas here... seems like a smart move of CK to poll this community for ideas. I especially like the DSP fuel gauge option (Similar to Line 6 as 'The Sage' pointed out immediately)

Thanks to Christoph for taking the time to weigh in on this - any option that gives control of resources to the user seems to be the way to go. We all have different needs I imagine... Although I prefer not to think of what Don Barzini's are... cue some reference to a "hard button"

Brett

CK, thanks for the informative reply...but, I too would rather see a good part of the extra DSP allocated to further improve the sonic performance of the unit. I bought the Kemper over the A-FX 2 due to the unparalleled realistic rendition of the amp tones and secondly the simplicity...Quite frankly that is the niche and strength of the Kemper and IMHO makes it stand above all other modelers. Improve what makes its strong! ....As the discerning guitarist would say..."Tone is everything...".

Quote from ckemper

We have a large headroom of calculation power left, that I was planning to keep for future features and improvements for upcoming firmwares.
However, it takes only three seconds for me to speed up our algorithms for the next firmware.
But this would eat up some of the headroom for the future.
Still we don't know how much headroom we will use in the future.

What do you think?

Why not just make it optional? Why not make the user be able to choose the right balance that suites their need, and let them choose where to focus the available power? So if you throw most of it on antialiasing, you would not be able for example to use as many effects... which you may not be using at all in the first place.

Another possibility could be (if doable) to make the power consumption dynamic, and always utilized. So whenever there is some free headroom, it simply gets utilized to deal with antialiasing, so nothing is wasted, and whole potential is utilized.