Kemper Amps Forum

Quoted from "Jimmyno"

Quoted from "Guitartone"

I just HOPE that the tone of the KPA never changes.

I'd rather not use the Metal DS stomp with gain on10 (never in a million years) than change the tone of the KPA so that the Metal DS stomp with gain on 10 sounds 'correct'.

Well, i agree. I absolutely love how KPA sounds, and i love it even more with the 1.09, since it doesn't need to add "compression" and "clarity" in the amp section to sound less spongy and mode liquid.
But those digital artifacts are definitely there, we all can hear them from the clips. It is honest to say that you'll NEVER hear them in a mix (studio or live).
Of course an address of those little issues would be a plus.
But other features like Perform mode and more FX are way more important IMHO.

Unfortunatelyy I've been way too busy to really test the current version beyond checking aliasing for this thread with that one patch , but are you saying the sound has changed? Can CK confirm whether anything has changed that would make it more "liquid" (and therefore in my mind less like the original amps and more like an amp sim)? This is a little worrying.

For the record, I don't go around looking for aliasing when I play - if it's *way in the background* it doesn't bug me too much. With the high gain Stomp ODs, I heard it immediately & obviously, so I started posting about it. I will not even have a chance to try 1.0.9 until our current tour is over (Dangit!)

I am very happy to see that Kemper is moving ahead on the various issues being raised, and believe the KPA is going to have it's greatest advances ahead!

Christoph: I love the new time-saving features and gates you added in 1.0.9

Quoted from "miles"

Quoted from "ckemper"

Quoted from "miles"

Quoted from "ckemper"

It's dependent in the gain. The amp allows much more gain than the stomps, and more gain than most tube amps. Where is your gain set to?

I have noticed the aliasing in the higher note register with nearly the entire range of gain in the KPA, from low to high from any profile, by any author. I have been profiling for the last several days, and when I A/B my source amp and KPA profile, it's very evident. Even if the aliasing is not jumping out at you, it kind of floats around in the background, almost subliminally.
I imagine that the sine sweep test by dhodgson would have likely demonstrated the noise with almost any amount of gain.

No, by physics the distortion aliasing level is a function of gain.
Hodgsons sine sweeps were high gain only.
I can easily create noticable aliasing on many modelers with sine sweeps.

Some stated to hear aliasing with clean guitar sounds. Yet to be demonstrated.

Here are sound files that that I made that demonstrate the digital artifacts in clean sounds that I mentioned earlier, and there are 2 to consider here:
I made these files by profiling a Grace M101 mic pre DI. The first file (Grace-KPA Clean Test 1) has two groups of high descending notes; I am A/B-ing the Reference amp, and Kemper amp straight to ProTools via the KPA's analog outs. The first group of notes are the Reference amp, and are very clear, the second group are from the Kemper amp, and to me it sounds similar to what I hear in the high gain aliasing... though how could that be? Perhaps it's more of the "burst" effect than the "wind howling", you be the judge.

Grace-KPA Clean Test 1

The next file (Grace-KPA Clean Test 2) demonstrates what I will refer to here as 'light distortion' on clean sounds. I find this artifact undesirable, and since no one seems to be noticing it, I figured it was time to reveal--it is apparent enough that I intend to refrain from any pure-clean profiling until it's fixed. If it's related to the aliasing, I just don't know.

Grace-KPA Clean Test 2

No stomps were used at all.

I can definitely hear it on the 1st clip (KPA part) but I think most of the people will not hear it. I find that the part were it is easier to spot would be in 2nd note you play with the KPA just after the note attack.

I also can hear that light distortion (or compression?) you mention on the 2nd clip.

Quoted from "Per"

Unfortunatelyy I've been way too busy to really test the current version beyond checking aliasing for this thread with that one patch , but are you saying the sound has changed? Can CK confirm whether anything has changed that would make it more "liquid" (and therefore in my mind less like the original amps and more like an amp sim)? This is a little worrying.

Don't get me wrong: i feel that the whole has become less spongy and more natural in the attack. I don't know if there's something about the new gate, about latency, about anything different in the algorithm, but i like it more than before.
I cannot exclude that it's just a "120% more real" syndrome

Quoted from "miles"

Here are sound files that that I made that demonstrate the digital artifacts in clean sounds that I mentioned earlier, and there are 2 to consider here:
I made these files by profiling a Grace M101 mic pre DI. The first file (Grace-KPA Clean Test 1) has two groups of high descending notes; I am A/B-ing the Reference amp, and Kemper amp straight to ProTools via the KPA's analog outs. The first group of notes are the Reference amp, and are very clear, the second group are from the Kemper amp, and to me it sounds similar to what I hear in the high gain aliasing... though how could that be? Perhaps it's more of the "burst" effect than the "wind howling", you be the judge.

Grace-KPA Clean Test 1

The next file (Grace-KPA Clean Test 2) demonstrates what I will refer to here as 'light distortion' on clean sounds. I find this artifact undesirable, and since no one seems to be noticing it, I figured it was time to reveal--it is apparent enough that I intend to refrain from any pure-clean profiling until it's fixed. If it's related to the aliasing, I just don't know.

Grace-KPA Clean Test 2

No stomps were used at all.

Thanks for those! It is pretty audible in both soundfiles through active monitors.
(Ha! No need to go play Jazz now for me! ).

Seriously - it's there - and clearly audible in both files.

I gotta say though - as clearly as those samples are - in the heat of playing - I haven't noticed these when I play mine. Must be in a different state of mind when I play...

yeah thats easy to spot..when its set out like that. and quite noticable too.
almost seems the profiling has gotton confused, and put a clean signal via a distored gain stage or 2. - (sounds like tubes are broken and on the way out LOL)

What guitar pickups were used for this test? - and do you have any other guitars to test with to see if you get the same level..
as it might just be default gain stage set a bit HOT in the KPA (clutching at straws here)

i just tried this, and dont get that problem, - or maybe its to do with SPDIF traffic? bad cable? interference.. anything.. again not based on fact just trying to eliminate everything possible so we can work towards an exact problem..

Is this test you done noticble while playing pre-record? - or record only?

Are your clean and distortion sensi at low levels? - and did you adjust these and did it make any differnce?

Do you get the same results on every pickup position?

have you tried a differnt guitar cable? and/or SPDIF cable?

if you turn the volume down to half on your guitar does it still appear?

Just tryng to figure out more.. so excuse the random questions...

A

Quoted from "miles"

MadH,
I can't help it if some people can't hear it, it's the ones who can that matter most to me. I'll bet any pro-studio engineer would recognize the artifacts in my sound files.

Sure, I did not mean it that way. It does not matter how many people notice it in order to take action to fix it. I was just pointing out that I thought that a lot of people would not be able to notice it (unless they used proper equipment like you suggested). My first audition of the 1st clip was using computer speakers and even if I noticed something off I could not hear clearly what it was. When I plugged in my studio headphones it was more obvious.