Kemper Profiling Amp



Can't you hear it in this clip?


Yup, I hear it there. So we have one clip, plucking single notes out of hundreds of clips where you can hear it. Are we absolutely sure it's a legitimate problem, or perhaps a faulty unit / reamping?

What I mean is, to what extreme do we have to go to to replicate this aliasing?
 
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Yup, I hear it there. So we have one clip, plucking single notes out of hundreds of clips where you can hear it. Are we absolutely sure it's a legitimate problem, or perhaps a faulty unit / reamping?

What I mean is, to what extreme do we have to go to to replicate this aliasing?

Well Kemper have acknowledged the problem, so yes. It is legitimate.

According to someone I spoke to, if the Kemper is doing dynamic convolution, and switching between convolution 'samples' based on the input amplitude... then you're going to get some frequency modulation when it switches between the different sets of samples.

At least that's my very basic understanding of it. Apparently it's inherent in the technology, which is why for the most part its a dead end. Obviously this is a massive assumption on how it works though - it could be completely different.
 
Well Kemper have acknowledged the problem, so yes. It is legitimate.

According to someone I spoke to, if the Kemper is doing dynamic convolution, and switching between convolution 'samples' based on the input amplitude... then you're going to get some frequency modulation when it switches between the different sets of samples.

At least that's my very basic understanding of it. Apparently it's inherent in the technology, which is why for the most part its a dead end. Obviously this is a massive assumption on how it works though - it could be completely different.

I wonder why we do not hear it in any other clips? Does it get masked in chords?
 
@Clark: When I deal with my Kemper I used to get some aliasing, but when I started to sync the clock with SPDIF and don't let the signal too hot on Kemper I stopped hearing it. I known Aliasing is not supposed to be related with those things.
(Anyways, did I became deaf, dummy or the aliasing disappeared?)

Can you hear it on this exemple?


Cheers!
 
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You guys who have Kempers should sell them because of this anti-aliasing disaster they created. Obviously, the people at Kemper have no competence and have ripped us all off with a product that doesn't work. The clips sound exactly like real amps but who cares?! There is a major, major anti-aliasing issue going on and they failed to disclose it properly. I can record top notch, full volume, pro-sounding guitar tones in the middle of the night without worrying about waking my apartment neighbors, but it's all a waste because of this horrible, awful anti-aliasing issue. What a scam. I want my money back. I don't want instant access to hundreds of different amps at my fingertips if it means I have to deal with this anti-aliasing problem, even if I can't hear it. This is fucking bullshit. Let's create a petition and sue Kemper. We need proper anti-aliasing rights. This is a bigger issue than simple guitar tones. This is about truth, prosperity, and freedom. Free James Brown!
 
You guys who have Kempers should sell them because of this anti-aliasing disaster they created. Obviously, the people at Kemper have no competence and have ripped us all off with a product that doesn't work. The clips sound exactly like real amps but who cares?! There is a major, major anti-aliasing issue going on and they failed to disclose it properly. I can record top notch, full volume, pro-sounding guitar tones in the middle of the night without worrying about waking my apartment neighbors, but it's all a waste because of this horrible, awful anti-aliasing issue. What a scam. I want my money back. I don't want instant access to hundreds of different amps at my fingertips if it means I have to deal with this anti-aliasing problem, even if I can't hear it. This is fucking bullshit. Let's create a petition and sue Kemper. We need proper anti-aliasing rights. This is a bigger issue than simple guitar tones. This is about truth, prosperity, and freedom. Free James Brown!

Lol.....

Yea i gonne sell mine to..

The kemper is to perfect....i am gonne back to my axe fx.

There to many great amps to choose from:Smokedev:
 
You guys who have Kempers should sell them because of this anti-aliasing disaster they created. Obviously, the people at Kemper have no competence and have ripped us all off with a product that doesn't work. The clips sound exactly like real amps but who cares?! There is a major, major anti-aliasing issue going on and they failed to disclose it properly. I can record top notch, full volume, pro-sounding guitar tones in the middle of the night without worrying about waking my apartment neighbors, but it's all a waste because of this horrible, awful anti-aliasing issue. What a scam. I want my money back. I don't want instant access to hundreds of different amps at my fingertips if it means I have to deal with this anti-aliasing problem, even if I can't hear it. This is fucking bullshit. Let's create a petition and sue Kemper. We need proper anti-aliasing rights. This is a bigger issue than simple guitar tones. This is about truth, prosperity, and freedom. Free James Brown!

Go back to your crystal balls and your conspiracy theories you faggot. No-one is saying the Kemper isn't good, and no-one is saying you should all sell it! Dick!:devil:
 
Seriously guys. This is how I see it. Amp modeling has been good enough to replace real amps for years already. POD HD, 11R, Axe-Fx, Overloud TH1 and TH2 and Kemper all have good enough amp modeling to where the majority of people just don't give a fuzz. Now pay attention to what I said: "AMP MODELING" so the thing where some products do fail is CAB MODELING. This is why the POD HD was completely unusable for me at least. None of the factory cabs were very good and no external impulse support lead me to selling both POD HD units I had.

So that would lead to two units that have support for other than factory cabs: Axe-Fx and Kemper. Also Overloud TH1&2 but they are software so kinda useless to talk about that since you can run a custom IR out of laptops with all of these units.

Personally I've come to the conclusion that the cab has way more effect on tone than the difference between let's say a Mesa Rectifier or Engl Powerball amplifier. Mesa cab vs Engl cab... that's a HUGE difference.

I think the custom IR slots in the Axe-Fx enables you to do what ever you want... even get those violin and bagpipe tones not that you'd ever use them.

I have heard that you can separate cabinet impulses from the Kemper profiles somehow. I think that is cool and probably the best way to get good tones out of the Kemper and that's how I would go about it.

The best tones I got out of the Kemper when I had it was profiling my Overloud TH2 match EQ patches. Those sounded great. The only reason I say I prefer the Axe-Fx is because it is sooooo easy to finetune everything without making it sound digital and to me at least the Axe-Fx feels more like a tube amp. Once again that's just my opinion.

It doesn't have to be a competition. There is no wrong and right when it comes to taste issues. All I know is that if you need to think about if it sounds digital or not you'd be better off using real amps and knowing that there's nothing digital in your signal chain.

I just feel like the modeling world is starting a next revolution where modelers can do things that analog amps can't. That is cool.
 
For what it is worth guys, Christophe has said this:

Aliasing is not really depending on Hardware structure or software algorithms or programming skills.
It is only a matter of the simple speed of the distortion algorithms and the calculation power consumed by that.

Therefore I found it a bit distracting that a competitor makes comparison tests about aliasing - as if less aliasing was a technical innovation.
Probably the comparison was done to justify the use of a loud fan and the high price :)

If I felt face to face with them - I mean mentally - I would rather start a revealing comparison about innovations and sound dynamics and so on.
But I think that is not a mature way to deal with competitors.
So, back to the topic.

Aliasing cannot be avoided in digital guitar amps, there is no amp simulation without aliasing. It is just a matter how loud it is.

The Profiler produces a bit of noticable aliasing on the highest notes of the guitar, or by harmonics.
Those are not noticed by a majority of users, that is why we have our algorithms set as they are.
You need to use artificial test tones to make the aliasing more obvious.
This aliasing virtually non existent on deeper notes or chords, or in a band or recording mix.
That is why we think we have found the right balance.

Half of the comments in this thread are obviously not about aliasing.
Aliasing is created by very high notes through heavy distortion only!
Aliasing does not occur on clean or crunch sounds, and not with deeper notes or chords.
If your problem does not fall into this category, you should post an audio clip.

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?

CK

So basically... if you care about reducing the aliasing, please let them know. They seem willing to improve it, but it will use extra DSP power. It could even be an option - standard VS high quality modes.
 
For what it is worth guys, Christophe has said this:



So basically... if you care about reducing the aliasing, please let them know. They seem willing to improve it, but it will use extra DSP power. It could even be an option - standard VS high quality modes.

The standard vs high quality idea is a good one.



I now have a huge problem with my Kemper.

Too many good tones to choose from. Fuck.

You poor bastard!
 
JEFF, how is the Metal Amp Pack fom theampfactory going?

We're beta testing right now, deciding on cabinets and mic positions for a few of them and refining from there. I've tested about a dozen new profiles for Andy in the last week, some of them are quite fucking cool! I'm not sure the order he'll be releasing them in, but right now we've been playing with a 6505, Recto, and 51530III.