Do all digital amps sound this way? What even is it? Mystery solving.

So, I've been hearing some annoying things in my Kemper for a while. It's a sort of phasing issue in the top end as the note decays. I've tried different guitars, different cables, different headphones, nothing helped.

Then I tried my old Axe-Fx Std. Different, but similar. Tried demos of ReAxis, Spark, Logic amps, and Toneforge. Again, slight differences but all of them have this phasing, kind of bitcrushy bullshit as the note decays.

Thinking it STILL might be a problem with cables or my interface, I got the bright idea to try using a software instrument instead, bypassing my interface and anything electrical in my apartment, working strictly in the box. So this is a virtual electric piano into Toneforge. Listen to the way the distortion kind of swooshes and disappears halfway along the decay of the note (at about half or 25% volume to the electric piano, it sounds a bit tucked into the background). The lower the velocity/amplitude of the note, the shorter the swoosh:
https://soundcloud.com/jntzero/dist-test/s-NV5bP

^You might need headphones or decent volume to hear it, hopefully you can hear what I'm hearing.

I notice that the more gain you use, the longer it takes for this swoosh to manifest itself, meaning that if you play a typical metal chug riff you're likely to not hear it. But if you play a dynamic, delicate solo with more of a crunch tone, it can sound like absolute garbage to me.

So my questions are:
a) What is this audio phenomenon called? I've heard of phase distortion (which is what I'd call the sound, but maybe it's something else).
b) Is there ANYTHING one can do to get rid of it? Like I said, Kemper, Axe all the way down to Logic's generic Distortion plugin react the same way.
c) Do ANALOG distortion pedals behave this way too, and I've just never noticed it?

 

Try headphones, you should be able to hear it. It's not a "problem" so much as it sounds a bit unpleasant and artificial I think. It mainly bothers me when I'm playing unaccompanied by myself, which is every day though.

I tried some Kontakt libraries where instruments were sampled with distortion already on them and I don't hear this type of decay. But if I turn on whatever distortion is built into Kontakt, it introduces it again. So I'm really leaning towards the idea that this is kind of a universal attribute of digital distortion, sort of like how stepping in filters is an unavoidable part of digital synths vs. analog ones.

 

That is incredibly helpful, thanks a lot! That makes a ton of sense too, I don't know much about bit depth or bit reduction but I do relate the sound of bitcrushers to what I'm hearing here. For now I'm just really happy to know what to google for, thanks to you! It's nice to find out something objective in the analog vs. digital discussion for a change.

 

Reading more about it, I tried the same test with and without sending white noise into the plugin. It took a lot of noise to get there but it did eventually make the quantization distortion inaudible. Cool, learned something about dithering in all of this I guess from now on if I want to play softly on the Kemper I'll have to ask my drummer to work the ride cymbal to dither me. https://soundcloud.com/jntzero/dist-test-dither/s-LjGEV

 

Can't really find any info on the Kemper's bitrate, unless you mean bit depth which is 24 on both the KPA and Logic. These examples weren't done with the Kemper though, I used Logic's own instruments, which I assume would be optimised in every way with Logic itself.

I also plug my Kemper into my Focusrite and directly out to my monitors most of the time, and while I can't find any bit depth toggles on my Focusrite I read its spec sheet to be 24 bit.

The input gain is plenty high, I'm just playing very softly.

 

Thank you so much for doing that! It's hard to tell if I really hear it in your examples, I'm not sure I do. My Nameless demo just expired, that's a bummer.

My Kemper isn't set up for reamping right now, but I did try your DI through Reaxis and Toneforge and they definitely had the artifacts going.

For the sake of comparison, as we both have Logic, would you mind running your DI through Logic's amp sim on the "A-List Clean" preset, full gain and no reverb? When I did, something very interesting happened in the noise of your DI. At about 5 seconds in (on my bounce), there's a serious bitcrushing swoosh happening, among other things. https://soundcloud.com/jntzero/flappydoodle-di-test/s-48mRT It's quiet, so try headphones.

I'm asking purely to understand what this phenomenon is a little better and rule out any problems in my setup, I'm normally not advocating for the use of Logic's amp sims ever

 

Oh sorry, I meant your own DI, which is what I used for my last clip

 

Yeah I thought something like that could be the case, which is why I was surprised (and a little relieved) to see the same results using a virtual piano in the box. That said, I did actually switch my interface to 88.2 and though it may be wishful hearing, I might think the Kemper sounds a little bit smoother in the high end now. I'm using TRS cables rather than S/PDIF so maybe my interface at 44.1 is slightly out of sync with the Kemper at 44.1, and using 88.2 makes up for that? This is pure speculation on my end, I know very little about how this works and that theory could be dead wrong.

I find it interesting though that after so much critical listening to digital guitar tone, I'm actually sometimes hearing what I think are digital artifacts in tube amp recordings. For example, this intro has all the warble and crackling in the high end that I associate with digital modelers, yet it is as far as I know a JMP.


^If you asked me now I would swear that was a Kemper, but that record came out in '97