VST3 implementation feedback

Yep, although first I want to get this as stable as possible. I’d be surprised if there’s a big difference in performance for most plugins. The main place where it might need tuning is with plugins with lots of input/output channels/busses. Currently Cantabile’s VST 3 implementation is enabling all I/O busses on the plugins and that could be optimized - which for some plugins might result in the VST 3 plugin running faster than the VST 2 equivalent.

Update: I’ve looked into the issues with both Softube and iZotope plugins and as best I can tell Cantabile is doing everything correctly. I’ve reached out to both companies to see if we can get this resolved.


Brad, I am testing 3620 with various VST3 plugins and most of it goes ok. Pretty exciting you’re getting this done!

I may have found a small bug/issue:

I was constructing a new linked rack to serve as a “Master Bus”, where I put Waves C6 stereo (VST3) and Izotope Ozone Elements (VST3) on it. Works all fine. But after saving it, exiting Cantabile, starting Cantabile again and loading the song with the linked rack in it, C6 “failed”, and it removed the input routing. (see picture)

I redid this several times, and it happens consistently.
If I replace the C6-VST3 with C6-VST2 it works fine

Maybe not your highest priority right now, but perhaps you can address this at some point.

By the way: still today (2nd October) Izotope Ozone Elements is free of charge! It’s good, so get it!

New build 3621 is up now and addresses some known issues.

Fixed in latest.

I’ve investigated this and looks like something wrong in the plugin where is successfully loads the data but then returns a failed code. (ie: if I remove the check for the returned error code the plugins loads fine).

I’ve contacted Waves for assistance with this.

Currently in discussion with iZotope about this.

The problem here is that the VST 2 PianoTeq plugin has a bank of native presets, but the VST 3 edition doesn’t - so only the current program (or perhaps the first program) gets upgraded. I’ve reproduced this in Cubase. If this is a problem for you then I suggest contacting PianoTeq as there’s nothing Cantabile can do about it.

Fixed in latest.


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Hi @Brad

For Softube Vst3 plugins everything run smoothly now, you did it, thanks ! :slight_smile:

now iZotope and we’re good (at least for me), except the OPX-Pro II random crashes problem (I don’t have time right now to try what you suggested by email, i’ll do it when I’ll have some time last week).


Hi Brad,
Thanks for your new update 3621. Will check it
I have noticed in 3620 also an issue with Waves SSL G Bus compressor. The VST2 version works fine. The VST3 lets the audio thru but does not do anything. The meter is not reacting whatever threshold value I enter. Seems something wrong with that one as well.

Another bug : bypass the plugin FX stops the sound passing thru these vst3 plugs

  • U-he FXs (Color copy, Presswerk, Satin and Twangstrum)
  • Slate Digital : VBC, Verbsuite Classic and Lustrous Plates (Liquidsonics), VMR, VTM, Eiosis Air Eq and E2Deesser, Overloud TH-U Slate,
  • GGaudio Spin

For these the bypass functiun normally :

  • Arturia FXs
  • Softube Volume 2
  • IK Amplitube 4 (for the Leslie)
  • GSiRotary

Think I’ve found similar problem in 3615. Sometimes i get a phasing effect when bypassing

Thanks I’ll look into it.

I’ve had a look at this and it was a problem with the default way audio ports were getting configured where the input ports couldn’t be mapped to output ports because of port naming differences in VST 3 (compared to how it worked with VST 2).

Anyway I’ve made a fix for the next build which works with a selection of the mentioned plugins. Let me know if there are others.


Update on upgrading Arturia plugins from VST 2 to 3. Basically it seems they’re broken and doesn’t look like they’re planning on fixing it.

Their suggestion:

  • Save the preset your were using on the track
  • Create a new instrument track
  • Instantiate the VST3 version in the new track.
  • Load the preset saved on the VST2
  • Copy the automation lines from the VST2 track to the VST3 track. (If you have some)

Send me an repro example and I’ll look into it.

Hi @adderoo,

I’ve got a full installation of the waves plugin (v10) but don’t see a plugin with the name “SSL G Bus compressor”. Exactly what name is this plugin showing for you in the Insert Plugin window?

Also, perhaps give it a go in 3622 which has some fixes for the default audio port mapping. Make sure you insert a new instance and see if it works any better.


These should now work correctly in 3622.

Everything works as intended now, thanks !

Brad: on the Waves SSL plugin: It is called SSLComp Stereo. In 3622 the issue persists. It seems that changing the gain is working fine, but the meter does not respond. E.g. in Reaper and Cakewalk, this VST3 works fine, including the meter.



Ah ok got it. Yep I can see that. Same problem happens in VSTHost. Obviously this is depending on something from the host but pretty sure I’ve implemented all the interfaces. I’ve pinged Waves to see if they can shed some light.

Hi Brad,

Update on my testing of VST3 plugins:

  • iZotope Ozone Elements and Neutron Elements: they work ok if you use them within a song. If you try to remove them while Cantabile is on Play, Cantabile almost always crashes (without giving an error report option)
  • Waves plugins VST3 versions: they work of if used in a song, but many of them do not work anymore once you open a saved song with those plugins part of it. This happens e.g to Waves C6, Waves SSL Comp Stereo, Waves L3 LL which are all ones I frequently use

I get an occasional crash of the Reason Rack VST3-only plugin, but have the feeling this is more a Reason issue, as I have the same happening in Reaper (screendump enclosed)

Hope this helps

Kind regards


For the moment for sure we can still work with the VST2 versions, which work fine

Hi @adderoo

Thanks for follow up:

Re: iZotope plugins, I was in discussion with them about this but they went dark. I’ll follow up today

Re: Waves plugins, in discussion with waves still.

Re: Reason Rack, that looks like a bug in there plugin. And it looks like it’s a debug build of the plugin because release mode builds shouldn’t give asserts. Weird.