Small bug - mono delay plugin

I have noticed something weird with the mono delay plugin. I’m working on a project that only uses about 10% of the cpu. After using the monodelay plugin for some time, the CPU meter will slowly begin to rise. It continues to rise for about 5 seconds until it reaches 100% cpu usage, and it maxes out and makes a distortion sound - then it immediately returns to 10% cpu again. Can anyone confirm? I haven’t noticed any issues with the other plugins I have been running so far.


Hello Todd,

which operating system do you use, are you working 32 or 64 bit, which soundcard ?



Hi Chris,

I’m on Windows XP Pro (32-bit). I have 2 RME HDSPe AES cards installed…


Hello Todd,

I cannot reproduce it here on Windows 7 and Cubase 6.

with the CPU meter, do you mean the CPU meter in the taskmanager, or do you mean the ASIO performance meter in Cubase ?



It’s the ASIO performance meter in Cubase. If I push the latency up higher, it becomes much less noticeable. At very low latencies is where it begins to be a noticeable problem. As soon as I disable the plugin, the problem goes away. I will test again on a different project file to see if it occurs there as well. I’ll report back soon…

If the problem occurs again, please report if it helps to switch the plug-in off and on again.
Please make sure you really use the on/off switch in that case and not just the GUI close switch.
A few people mix that up. I’m sure you wouldn’t :wink:

It doesn’t seem to matter if I switch the plugins off & then back on. It seems to happen constantly with this mono delay plugin no matter what I do… every few minutes, I get glitches & noises, then things return to normal.

One thing I forgot to mention - I decided to experiment with 192khz, so this whole song is at 192khz. All of the other plugins I am using seem fine at 192, but the mono delay plugin definitely is causing some type of CPU bursts. I wonder if this plugin has a problem working at 192?

For what it’s worth. I’m on XP too but can’t seem to reproduce the problem at 48Khz, but I do get an occasional spike from that plugin at 96Khz though (my card does not support 192Khz)
I used 32 ms buffer size for testing.

This would seem to be the missing pertinent infromation! 192KHz

Yes, I should have mentioned 192khz earlier.

By the way, I tried replacing all of the instances of the mono delay plugin with SoundToys Echoboy, and it fixes the issue, so I know it’s the mono delay plugin causing the weird CPU issues…

I get the same problem. Mono Delay creates a distortion and the stereo output meter clips and doesn’t reduce in dB (even though the distortion only lasts about two seconds). The meter will reset when I remove the plug-in.

I also get the same problem when using Prologue. But i haven’t experienced the issue since the last update. However, I haven’t tried to recreate the issue so it may still remain.

I’m on mac OS 10.6.6 32bit mode sample rate 96000 so it seems to be an overall bug in the system.

I also get cpu spikes and dropouts all the time.

looking forward to the next non-beta update.

So we have confirmation of the bug then… I’m not alone in this problem.

Good to know! With this type of information I can have a look at it again.

Thanks Andreasm. Sorry I didn’t mention it before…