Kemper Amps Forum

Quoted from "MadH"

It does not sound like digital aliasing to me but something else. Do you get the same noise with the noise gate disabled?

Yes, the noise gate doesn't make any difference.

The reason I'm calling it 'aliasing' is because Kemper told me that there were aliasing issues on the distortion stomps that will be fixed on the next firmware update, however, the nature of the amp noise sounds almost exactly like the stomp noise to me, but Kemper says its "something different". I did a test where I turned off everything but the dist stomp, heard the "aliasing" noise, then turned off the stomp and turned on the amp and heard the same noise--which I am referring to as 'aliasing' due to its similarity. Just a coincidence?
So, if it is true that the stomp "aliasing" will be fixed, then that's great, but, if according to Kemper, this "wind howling" really is different in regards to the amp profile, then it concerns me a bit as to whether it's fixable in firmware--after all, the amp profile is what likely consumes most of the processor's horsepower.
I don't want to overstate or seem alarmist about this, because the KPA is seriously rocking my studio right now, but a precision, pro unit like this deserves the scrutiny.

By the way, does anyone know the bit depth and sample rate of the KPA? (A reasonably high resolution is desired).

Quoted from "mikeb"

I hear this type of thing via SPDIF any my EMU sound card, the SPDIFs are incompatible in my case, I just switch over to the XLR outs and I am fine. No high end digital aliasing.

I too am using the analog outs--I'm curious, if you tried a test similar to mine it would seem that you should experience the same thing. I assume you listened to my sound file and heard the noise? It is subtle.

I have a second KPA coming here in a few days, and will of course be A/B-ing to be sure.

Quoted from "guitarnet70"

Another fellow dropped me a PM regarding this thread: Is this not the same Aliasing, Pulsing, Numerical noise issue that have popped up 1 month ago and has been solved?

There are a couple of threads already, GeneAndEddy was the guy IIRC..... Search for "Numerical Noise" or "Aliasing" and you'll find it

The issue I raise has clearly not been resolved, as I have the latest firmware, and the acknowledgement of Kemper. I guess the answer is no.

Quoted from "r_u_sirius"

this "suffocating alien" noise on high notes is there in almost every hi gain profile....not good!

Great description, "suffocating alien"! If you play the same high notes with a clean sound (preferably with 'phones on and listening very closely), the noise has more of an atonal drone compared to the high gain noise which modulates a little bit--they both are related to the same issue, I imagine. It is probably the only reminder sound-wise that it's a digital device that otherwise sounds nearly analog.

I'm super-curious how and when they can remedy this--best of luck to them!