How to get stuck notes (and how to get rid of them)

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873 posts since 22 Mar, 2005 from Germany

Post Wed Mar 11, 2020 6:17 am

Hi everyone,

since we got a few reports of stuck notes in recent weeks, we thought it might help to explain some situations in which notes can get stuck.

We'll start with a list of known issues in some of our plugins.
Next, we'll list some other scenarios which can lead to stuck notes, but are out of our control.
And finally, we'll post a few simple steps to stop stuck notes once you got them.
So let's start.

Scenarios unique to u-he plugins

Diva 1.4.4 (rev. 9709) stuck note in arpeggiator

In the current version 1.4.4 of Diva, it's possible to get a stuck note when using the arpeggiator.
It seems to happen at a random point, after switching between different arp presets for a while.
Once it started to produce those note hangers, it will do so again when playing an arp preset.
So the best option is to reload the plugin at this point.
This is clearly a bug in Diva, and we aim to fix it for the next update.

Stuck notes when playing MIDI notes while the plugin is bypassed

There is a way to sometimes get one or more stuck notes in ACE, Bazille, Diva and Hive.
Many hosts will have some sort of plugin bypass button (which is not the plugin on/off switch many hosts provide).
Some hosts won't send any MIDI data to the plugin when it's bypassed, or they simply don't have a bypass button, so there won't be any problem.
But some hosts (e.g. Cubase or Pro Tools) will still send MIDI data to the plugin while it is bypassed.
Once you unbypass the plugin, it will do a check and stop notes from falsely starting to play if there was a missing note-off event.
But if more notes than active synth voices have been played, it is possible that the plugin does not catch all notes.
This will then result in a stuck note when unbypassing the plugin.

One example:
You have the plugin's voices set to eight.
You record some MIDI chords (i.e. more than eight notes) into your host, and at the same time record the plugin's audio.
Now you want to check the recorded audio, so you bypass the plugin, and play back the recording.
The MIDI clip will send the notes to the plugin while it's bypassed.
And when being unbypassed, a note might slip through the check and start playing on its own.

This won't happen every time, but it can happen in the mentioned plugins.
One possible workaround would be to mute the MIDI clips instead of bypassing the plugin.

Stuck note when adjusting velocity pointers in Bitwig

Again, this is something which can happen in ACE, Bazille, Diva and Hive.
It will happen only in Bitwig.

* have a polyphonic preset selected
* in Bitwig's MIDI clip, select multiple notes and adjust their velocity pointer
* this will play a preview of the notes
* if you selected three or more notes playing the same note (e.g. if all three play a C3), you might get a stuck note while adjusting the velocity

We will, of course, try to improve these problems in future updates.

Seemingly stuck note when hitting notes on the graphical keyboard

Hive and Repro do have graphical keyboards.
If you double-click a note on those keyboards, the note will be held.

Now here comes a sentence I really like: "It's not a bug, it's a feature." :wink:

This function helps if you don't have a real MIDI keyboard and you want to adjust something on the preset while listening to the sound.
To stop the note from playing simply click on any other note in the graphical keyboard.

Those were the u-he specific topics.
Now on to some cases which are out of our control (and can happen with many plugins from many developers).

Stuck notes in connection with the plugin on/off switch

Most hosts will provide a plugin on/off switch or plugin deactivator, or something alike.

* choose any plugin (does not need to be a u-he plugin)
* hold some notes
* while still holding them, deactivate the plugin
* release the held notes
* reactivate the plugin

There is a good chance you are now being greeted by a lot of stuck notes.
Or you won't hear stuck notes instantly, but once you play some of those same notes again, they will be stuck.

In many hosts this mostly happens when using a VST3 plugin.
But there are other hosts, like Reaper, where this happens with VST2, VST3, and AU plugins.
So it can be a problem for all plugin formats.

Stuck notes in connection with Studio One's qwerty keyboard

So far I found five ways to produce stuck notes when using the qwerty keyboard feature in Studio One.
None of those is in our control, i.e. it's not a bug caused by u-he plugins.
All of these can happen with lots of different plugins, even with Studio One's own integrated plugins.

1 - Stuck note when loading a VST3 plugin

* load a VST3 synth plugin, and open the qwerty keyboard GUI
* hit some of the qwerty keys or numbers on your physical keyboard, to make sure the qwerty keys work
* now adjust some setting in the plugin with the mouse, doesn't matter which setting, just make sure to mouse-click into the plugin GUI so it gets focus
* now load another VST3 plugin (or one of Studio One's integrated plugins, like Mai Tai or Mojito)
* hit one of the qwerty keys on your physical keyboard, and the note will get stuck
* you can see the key stays lit on the qwerty keyboard GUI
* this seems to happen because the qwerty keyboard doesn't have the focus (not sure if it's mouse focus or key focus that's missing)
* this only happens when using VST3s, it does not happen with VST2 or AU plugins
* to avoid this from happening, click somewhere on the qwerty keyboard GUI once, directly after loading the second VST3 plugin

2 - Stuck note when using the CMD key

* hold the CMD key while hitting one of the qwerty keys on your physical keyboard
* this seems to act like some kind of hold function
* but there seems to be no way to send a note-off to that note, so it will be stuck

3 - Stuck note in connection with MIDI input selector

* at the right top section of the plugin GUI, click the little triangle between the cogwheel and the field that displays "QwertyKeyboard" as the currently selected input
* this will open the selection menu for the MIDI input
* while it's open hit one of the qwerty keys on your physical keyboard, and the note will be stuck

4 - Stuck note in connection with the Caps Lock key

* either click on the qwerty keyboard GUI or click somewhere in the Studio One UI
* now hit one of the qwerty keys on your physical keyboard
* while still holding that key, hit the Caps Lock key
* this will produce a stuck note for most of the keys, since many keys will then control some function in the Studio One UI, and will close the qwerty keyboard

5 - Stuck note when closing qwerty GUI

* hold one of the qwerty keys on your physical keyboard
* while still held, close the qwerty keyboard GUI
* this will result in a stuck note

So, you got yourself a stuck note, and you don't like it, what can you do about it?

There are several ways to get rid of them:

* some hosts might send a reset when using the host transport start/stop
* some hosts might have some kind of "panic" button or feature to send an "all notes off" message to plugins
* in u-he plugins you can select another preset, or reload the current preset to stop most stuck notes
* you can also change the voice mode (e.g. from poly to mono and back) to stop stuck notes
* you could also change the number of voices in the plugin to stop those dreaded notes
* or use MIDI CC123 to send an all notes off command to the plugin
* if nothing else helps, reload the plugin

If you happen to find other reliably reproducible ways to get stuck notes, then please post them here.
If we can reproduce and confirm any additional issues, we will add them to the first post of this thread.

If you happen to get stuck notes you cannot explain, and are pretty sure it's a bug in our plugins, then please contact our support and we will try our best to determine if it's a bug or if it's caused by circumstances which are not under our control.

There might be many more ways to run into stuck notes than listed here.
Often they are tied to just one specific host, which doesn't deal as well with certain scenarios as most other hosts.
So if you run into unexplainable stuck notes, it might be a good idea to check the host forums for similar reports.

We know experiencing stuck notes can be frustrating.
But please be aware that it might not always be the fault of the plugin developer.
We hope this post helps to explain the majority of situations under which you might run into some stuck notes when using our plugins, so you know why it happens and how to fix it.


Joe Leidigkeit
49 posts since 29 Sep, 2006

Re: How to get stuck notes (and how to get rid of them)

Post Thu Mar 19, 2020 3:42 am

Thank you for this detailed Info.

21 posts since 7 Apr, 2005

Re: How to get stuck notes (and how to get rid of them)

Post Tue May 19, 2020 9:10 am

When sent two successive note-on's of the same note, Zebra2 will require two note-off's to release them both, whereas other plugins (eg NI Massive) will only require one note-off. Some MIDI generator plugins (eg Instachord/Instascale) assume the latter and can cause stuck notes.

1 posts since 23 May, 2020

Re: How to get stuck notes (and how to get rid of them)

Post Sat May 23, 2020 4:35 am

I can reproduce the hanging note issue like this in REPRO5 (DAW: Reaper):

Write two chords in midi format (the last one should be a bit longer, just for demonstration porpuses as you will see). Than hit play and wait until the second one is played but hit the stop/play button before the second chord ends. The first chord will be played forever.

My Solution: simply play the chords again and dont stop before the stuck note ends.

This issue occurs for me when I ve polyphonic material. I ve tried a lot within REPRO 5 (Tweaks/SYNC/AMP/FILTER section)...same behavior.

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