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IDProjectCategoryView StatusLast Update
0008939ardourbugspublic2022-08-12 19:14
ReporterNonlinear Assigned To 
Status newResolutionopen 
PlatformMicrosoftOSWindowsOS Version10
Product Version6.9 
Summary0008939: Some VST3 plugins produce no output - ALL VST3 plugins show I/O error in plugin manager
DescriptionEvery VST3 plugin I have checked in Ardour's plugin manager shows the following errors:

[Info]: VST3: \ error getting busInfo for bus: 0 rv: 0, got type: kMain
[Info]: VST3: \ error getting busInfo for bus: 0 rv: 0, got type: kMain

Some VST3 plugins work properly while others receive input but produce no output back to the DAW - like they are perpetually bypassed. They LOOK like they are working (their meters move, etc.) but the processed sound is not returned to the DAW.

VST2 versions of the same plugins work properly.
Steps To Reproduce0000001) Scan plugin in plugin manager and view report. (All VST3 plugins report I/O bus errors.)
#2) Insert VST3 plugin in any track or bus and listen for output change when turning knobs, etc. (Some plugins work, some don't.)
TagsNo tags attached.


duplicate of 0008920 new VST plugin issue with multi-output plugins 
related to 0008855 new No audio inputs for Surge VST3 



2022-07-09 20:34

reporter   ~0026499

There appears to be no way to edit my post so I will add info here. This issue is with regard to 3rd party VST3 plugins - of all brands. Some work some don't but ALL report the I/O error. The reason I marked this "major" is because a user can inadvertently think the plugin is working when it is in fact not affecting the audio at all.


2022-08-12 13:45

administrator   ~0026559

At this point it time Ardour's VST3 host supports only "one main bus, and one aux-bus. Also an optional aux-bus by itself is currently N/A.


2022-08-12 13:47

administrator   ~0026560

Which plugin(s) are affected by this?


2022-08-12 17:50

reporter   ~0026563

>>At this point it time Ardour's VST3 host supports only "one main bus, and one aux-bus. Also an optional aux-bus by itself is currently N/A
The error I am reporting here is shown for all VST3 plugins including 2in/2out plugins. Every VST3 plugin I have checked in plugin scan shows this error "[Info]: VST3: \ error getting busInfo for bus: 0 rv: 0, got type: kMain". Some VST3 plugins produce audio output while others simply pass the signal thru unaffected.

>>Which plugin(s) are affected by this?
It's not specific to any particular plugin brand or plugin title - and those plugins that don't work in Ardour work fine in all other DAWs. Therefore, there appears to be a VST3 interface issue in Ardour.

If others users have noticed this issue they probably blame it on the plugin(s) and move along. Please do some checking on your own and don't take my word for it!


2022-08-12 17:58

administrator   ~0026564

Yes, as I said above it is not a plugin issue, but missing support for specific VST3 configurations in Ardour

I am curious if you have a VST3 that has more than one output bus or announces an output bus as main out, and hence does not currently work correctly in Ardour.
So far the only one I know is Addictive Drums in multi-out mode.


2022-08-12 19:14

reporter   ~0026565

To be clear, there are two problems here:

1) EVERY VST3 plugin shows up in the Plugin Manager as having I/O bus errors - including major brands like Fabfilter, Izotope and Waves. Please see attached screenshots. This is not due to a "specific VST3 configuration".

2) Some plugins, even those with only stereo I/O (no aux buses) - do not process the audio and pass it through unaffected. AFAIK, all plugins announce their main I/O bus as "Main". That is the Steinberg VST3 default labeling for main pins regardless of any aux pins. I cannot explain why some plugins work and others don't.
Ardour VST3 errors.png (165,978 bytes)   
Ardour VST3 errors.png (165,978 bytes)   

Issue History

Date Modified Username Field Change
2022-07-09 20:27 Nonlinear New Issue
2022-07-09 20:34 Nonlinear Note Added: 0026499
2022-08-12 13:42 x42 Relationship added duplicate of 0008920
2022-08-12 13:44 x42 Relationship added related to 0008855
2022-08-12 13:45 x42 Note Added: 0026559
2022-08-12 13:47 x42 Note Added: 0026560
2022-08-12 17:50 Nonlinear Note Added: 0026563
2022-08-12 17:58 x42 Note Added: 0026564
2022-08-12 19:14 Nonlinear Note Added: 0026565
2022-08-12 19:14 Nonlinear File Added: Ardour VST3 errors.png