Bypassing plugins and residual audio buffers

Hopefully someone can help me here as this has been an issue for years for me in Cubase, and I’m hoping it’s just a setting I’m missing. If I write automation on the bypass of an effect, when the bypass reopens the audio that was in what I presume is the buffer of the plugin starts playing immediately. I notice this most on delays used as inserts, for example if a delay is on for a word early in the track, then goes into bypass, then comes back out of bypass later, the word from the first phrase can briefly be heard as that data is presumably in a held state. Is there a better way to do this besides always having to utilize sends and mute that tracks automation to get around this issue?


Are you automating the bypass or the host bypass? Try the other one. Yould could also automate the wet/dry mix knob on the plugin.

So I am aware of two locations - the bypass toggle on the insert slot itself, and the bypass toggle at the top of the window when you open the insert effect. I always assumed these were one in the same because they both toggle/untoggle together, but I just noticed on hover one says “bypass insert” and the other says “bypass effect”. The only other way I’m aware of bypassing is within the effect plugin itself, but often these are not automatable and don’t show up in the generic editor version, and my understanding is that if they are not visible in the generic editor for a plugin, they can’t be automated. Thoughts?

“Bypass effect” and “Bypass insert” are identical. They should have the same label. They are different than “effect on/off”, which is the blue button next to the bypass button on the plugin window. You can access “effect on/off” from the inspector by alt/opt clicking on the bypass button.

But, here’s the thing. I believe you’ve found a bug. It looks to me like bypass is not working correctly. As I understand it, it should continue to run the plugin while bypassed, but discard the output. It doesn’t seem to be doing that.

Effect on/off I am familiar with, alt clicking, but that can’t be automated and even if it could, it fully unloads the plugin if I’m not mistaken. I agree its probably a bug, I guess I’ll file a report.

Just fyi, effect on/off does not unload the plugin. But you’re right, effect on/off is not useful for automation.

Can anybody else chime in on this issue? Bypass seems broken, but I’ve never looked very closely at this before, so maybe there’s an explanation?

Hey Glenn - out of curiosity, what exactly DOES it do then when you turn an effect off? I know it is more resource intensive to turn a plugin back on vs removing a bypass, and bypass doesn’t affect channel latency but effect on/off does.

Turning the plugin on/off entails some initialization. For example setting the sample rate. Bypassing has no effect on the plugin, which permits seamless audio. That’s why your observation seems to be a bug.

Martin, can you confirm whether this is a bug or if it is working as intended?

Turning the plugin on/off will create a gap in the audio during playback, because Cubase needs to recalculate the latency compensation.

Martin, can you confirm whether this is a bug or if it is working as intended?


There is no other way but use Send. This way It works as specified.

In that case the specification has a bug :slight_smile:. Bypass on other DAWs works like, well, bypass.


The question is, if you bypass it on the input side (so the plug-in is not feed anymore), or if you bypass it on the output side. Both have own pros and cons.

What you’re describing is muting of the input. You’re right, that can be very useful. That’s probably the intended behavior, but no, that’s not what Cubase is doing.

I tried this in Cubase 6 (amazingly, that still works :slight_smile:), and it’s working correctly there. So, it was working correctly at one time.

Glenn, OP and other readers,

I posted about a similar, perhaps related issue (it may be the same). This thread seems to be the central place to discuss this.

This is my other thread for reference:

My issue is this. Automating the Bypass of the stock Mono Delay on a track causes a slight, but noticeable timing “glitch” in exported Audio Mixdown. This may not be a Cubase issue since I’m using a 64-bit VST2 instrument. But, it’s odd. All that’s happening is the Mono Delay plug-in is being Bypassed on the last 16th note of a previous measure. It plays fine in Cubase, but the exported Mixdown has the glitch – a slight noticeable stutter in the timing song.

the bypass in Cubase does not turn the plugin off, it just takes the plugin out of the signal chain
but the signal path is still delay compensated, it works as intended

turning the plugin off changes the signal path and produces a drop out
this has nothing to do with intention, it’s just physics
if you turn a plugin off there could be a reason to do this so it is helpful to have both options

to automate FX it is better to automate the return of send effects rather than insert a delay or a reverb on a channel
or a combination of send automation and return automation could do the trick…

The bug is:

The DAW should continue to process the plugin when it is bypassed, but Cubase is failing to do so.

It worked correctly in an earlier version of Cubase. It’s not a big problem, there are workarounds, which is why this bug has gone undetected, but it is not working correctly. Without knowing more about Stephen57’s problem, it is hard to say if that is related to this bug or not.

The bug is:

The DAW should continue to process the plugin when it is bypassed, but Cubase is failing to do so.

what you mean with process… the bypass takes the audio signal and move it around the plugin without processing
that’s what it is for… that’s why it’s called bypass