Login / Register  0 items | $0.00 NewWhat is KVR? Submit News Advertise
tbarnaby
KVRer
 
13 posts since 30 Jul, 2017

Postby tbarnaby; Mon Jul 31, 2017 2:19 pm Bad clipping when using amp sims in real time

Hello,

I'm using Reaper as my DAW and Behringer UMC404HD as the audio interface.

The amp sims / Cab IRs are working great on a dry recorded track. However, last night I wanted to just rehearse a bit using the amp sims. So I set up Reaper to monitor the recorded signal so I could hear the amp sim in real time. However, there was a significant amount of clipping occurring in the monitor mix. At first I thought it was level related, but I turned everything down and it still happened. And it happened during loud and soft parts. The clipping seemed to reduce when I removed some unneeded effects, but did not go away entirely. So I'm wondering if this is processing / buffer /latency related since the software can't "look ahead"?

Are there some settings I can tweak to make this use of the sims (real time practicing) sound better?

Thanks!
User avatar
EvilDragon
KVRAF
 
14664 posts since 6 Jan, 2009, from Croatia

Postby EvilDragon; Mon Jul 31, 2017 2:46 pm Re: Bad clipping when using amp sims in real time

What's your CPU usage like (check it in your OS's performance monitor, not Reaper's)?

Sounds like audio dropouts rather than clipping.
tbarnaby
KVRer
 
13 posts since 30 Jul, 2017

Postby tbarnaby; Mon Jul 31, 2017 4:18 pm Re: Bad clipping when using amp sims in real time

EvilDragon wrote:What's your CPU usage like (check it in your OS's performance monitor, not Reaper's)?

Sounds like audio dropouts rather than clipping.


Overall CPU usage is about 30%. Looking at the individual cores, one core is at 50% and the rest are lower.

Could be dropouts maybe, but its very static-y sounding. Happens about every 2-5 seconds when playing.
User avatar
Kazrog
KVRian
 
854 posts since 24 Oct, 2009

Postby Kazrog; Mon Jul 31, 2017 4:50 pm Re: Bad clipping when using amp sims in real time

Sounds like a buffer underrun. Many times, it's the audio interface drivers creating a bottleneck (especially with budget hardware.) If you adjust your buffer and/or sample rate, you can probably arrive at something acceptable.

More info would be useful, though:

  • Operating system / version / bits (32 or 64)
  • DAW (recording software) / version / bits (32 or 64)
  • CPU make/model/speed
  • Audio interface hardware
  • Sample rate and buffer size of your session when experiencing the issue
Shane McFee
CEO/CTO - Kazrog LLC
tbarnaby
KVRer
 
13 posts since 30 Jul, 2017

Postby tbarnaby; Tue Aug 01, 2017 11:00 am Re: Bad clipping when using amp sims in real time

Ok, I tried a bunch of stuff before posting the question. But I didn't try rebooting, which cleared up the problem. Sorry - rookie mistake. Thanks for the help guys!

Just for your information ...

* I tracked the problem to the amp simulation plugins. Recabinet was fine, every Kazrog amp sim I tried had the issue. However, Lepou amp sims worked fine with no sound issues.
* I tried changing the quality level on the amp sims but that had no effect.
* Other details ...
OS: Window 10 64bit
DAW: Reaper v5 x64
CPU: AMD A10-7700K, 3.4GHz
Memory: 16GB
Audio Interface: Behringer UMC404HD
Sample rate: 48K
Buffer size: Two possible relevant settings in Reaper
Request Block size: 512
Media buffer size: 1200ms
tbarnaby
KVRer
 
13 posts since 30 Jul, 2017

Postby tbarnaby; Wed Aug 02, 2017 3:03 pm Re: Bad clipping when using amp sims in real time

Here's a little more information and a workaround/solution for anybody else that might experience this.

* First I was wrong that the reboot completely fixed this. It might have helped, but I think the main thing was that I was experimenting with a different Thermionik amp sim. I've noticed that some Thermionik amp sims are ok, while others are nearly unusable (as a real time solution). Just as an example, the Damage 120 is nearly unusable, while the Plexi is ok (a few pops, but manageable).

* As I mentioned before, the Lepou amp sims all worked ok with maybe a slight pop here and there. BIAS amp sims also worked with just a few pops here and there.

* I tried tuning a bunch of settings, but only one helped. In the UMC404HD control panel, I changed the "USB Streaming Mode" setting from "Low Latency" to "Standard". And that cleared up the problem for all the amp sims that I've tried so far. Also, at this setting I do not notice a delay between what I'm playing and hearing - so this is fine. The next level up is "Relaxed" and I definitely hear a delay there.
Jotunbjorn
KVRer
 
5 posts since 27 May, 2016

Postby Jotunbjorn; Sun Sep 03, 2017 8:18 am Re: Bad clipping when using amp sims in real time

I think I ran into this bug today. When loading a project in Reaper that has the Damage in one track I noticed that the CPU usage was way higher than normal. Loading a preset in the plugin rectified the problem.
User avatar
Kazrog
KVRian
 
854 posts since 24 Oct, 2009

Postby Kazrog; Sun Sep 03, 2017 9:18 am Re: Bad clipping when using amp sims in real time

One thing to keep in mind is that none of my plugins work as well on AMD CPUs as they do on Intel. Intel lost a class action lawsuit over this - it's related to their math library, IPP, that is used in all of my plugins and is supposed to be AMD compatible. It's great, and makes things like Thermionik and KClip possible, but it's not smooth sailing on AMD hardware always. If you get to know the quirks of your machine, you can make it work, though.
Shane McFee
CEO/CTO - Kazrog LLC
Jotunbjorn
KVRer
 
5 posts since 27 May, 2016

Postby Jotunbjorn; Sun Sep 03, 2017 10:25 am Re: Bad clipping when using amp sims in real time

I did some digging. It seems that the Savage just has super high CPU usage when both smooth mode and power amp depth are on. I have an Intel 3770K @ 4.5GHz.
User avatar
Kazrog
KVRian
 
854 posts since 24 Oct, 2009

Postby Kazrog; Tue Sep 05, 2017 9:18 am Re: Bad clipping when using amp sims in real time

Jotunbjorn wrote:I did some digging. It seems that the Savage just has super high CPU usage when both smooth mode and power amp depth are on. I have an Intel 3770K @ 4.5GHz.


That is true. I'm working on a lower CPU footprint Depth mode for the lower quality slider settings. The challenge has been making sure it still retains enough detail to not end up with that cartoonish low end you get from most other modelers.
Shane McFee
CEO/CTO - Kazrog LLC
StateOE
KVRer
 
25 posts since 1 May, 2010, from Han's Island

Postby StateOE; Thu Sep 07, 2017 7:50 am Re: Bad clipping when using amp sims in real time

Kazrog wrote:One thing to keep in mind is that none of my plugins work as well on AMD CPUs as they do on Intel. Intel lost a class action lawsuit over this - it's related to their math library, IPP, that is used in all of my plugins and is supposed to be AMD compatible. It's great, and makes things like Thermionik and KClip possible, but it's not smooth sailing on AMD hardware always. If you get to know the quirks of your machine, you can make it work, though.


This is interesting to know. I still use an old AMD FX-6100 on a build I made many many years ago, although I am still wanting to build a new machine with an i7, and all Thermioniks work well at Quality 6; I just disengage the Depth on all of them and force mono, because of course, Depth will destroy any of them. Until I do build my new machine, it is worth it to me to sacrifice the power amp low end control, then to make up for the low end on the IR. Thanks for explaining the details. I hear an extra roundness between Quality 5 and 6 that is utterly analogous to listening to the ride cymbals of a well mastered album at 44.1 kHz and 96kHz (not to open a Pandora's Box on this forum, so let me just say to those who disagree that you're completely and totally, infallibly right). I realize that I'm still running Thermionik at 44.1 in the end, but the internal oversampling really does make a difference to me, and feels completely and totally real. Anyway, very cool to know some of the mechanics of why your plugins work the way they do. Thermionik really is in its own class, too awesome for mortal computers haha!

In my opinion, it's a waste of your time to try to make Thermionik's Depth control work for less powerful systems. The things you've already achieved using your chosen techniques have been truly astounding, and I'm just curious to see where you go with your ideas. It sucks to have to divide resources between new, exciting research and experimentation and simply trying to make fantastically powerful plugins work all-encompassingly (à la Mitch Hedberg) with less powerful hardware. There is a world of plugins dedicated to working with even the least powerful of systems, but you have a niche here with Kazrog, something elite, if you will, and backwards hardware compatibility, for lack of a better term, is more akin to being all things to all people, and less meaningful. It's none of my business, but those are my two cents! I digress.

Moderators: Moderators (Main), Kazrog Mods

Return to Kazrog

Who is online

Users browsing this forum: CCBot (commoncrawl)