VCV Rack 2, Ableton, and Core Audio

I’ve been wrestling with some issues with VCV Rack 2 in Ableton Live. I’m on a 2020 iMac running OS 10.15.7, and Ableton Live 11.0.10. I’m also using an iConnectAudio2+.

VCV 2.0.2 was running pretty well with Live. I had some crashes, but most things seemed to be working. And there has been a learning curve.

When 2.0.3b came out, this was a different story. Several times Live became dysfunctional. The interface became unresponsive where I couldn’t trigger clips in other tracks or even get the transport to work, Push 2 would not initialize or respond, etc. Crashes are crashes, this was something else. It seemed like Live was broken. So I went back to 2.0.2 and hoped the next release would fix it.

So after installing 2.0.4, I’m still seeing the same issues. I’ve started debugging it and I thought I’d post what I found.

If I create an instance of Rack 2 on a Live track, and then try to load a patch, if the patch has an instance of an audio interface module like VCV’s Audio 8, and if the module is set to Core Audio and my interface, all of these problems I described can occur. These are the settings that would work for the Standalone program, so I am loading a patch into Live that I had developed or saved from VCV Rack 2 Standalone. This also has happened when I loaded other people’s patches. The key thing is that the audio interface module is defaulting to Core Audio, not to the DAW when I load the patch. The frozen aspects of Live occur as soon as I load the patch.

If I load a patch where the Audio 8 was saved with DAW as the selection, it loads fine and Live works fine.

If I load a patch that is saved with a setting for Audio 8 of Core Audio and not DAW, I can then change Audio 8 to DAW, but Live still remains basically frozen. If I then turn off Core Audio in Live’s preferences, and then turn it back on, then everything starts working as expected.

So far this has been pretty consistent. And I’m happy I found a work around. I’m wondering if anyone else has seen this issue.


Have u got original version of Ableton?

I’m not sure what you are asking. If you mean a legit license for Live, I own Live 11 Suite

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The more I work with this problem, the more I think it’s about how the VCV Audio module is allowing me to choose either the Core Audio directly, or choose the DAW which then Live routes audio signals to Core Audio. One time when I was testing, the Rack Plugin was playing audio with the Core Audio settings which froze up Live. I was able to eventually quite Live, but the audio kept playing without any process GUI.

It seems like the Rack plugin should never be allowed any audio routings except DAW

I can’t for the life of me figure out how the new DAW driver routes CV in Ableton - I’m on Windows rather than a Mac, but can’t get any of the inputs or outputs of Audio 16 to send or receive either audio or CV within the VST. Is there documentation anywhere on how to get things properly setup? I’ve been beating my head against a wall for the last couple of hours trying to get any routing to work. This was trivially easy running 1.16 stand-alone, and only reason I bought the Pro version was for the VST integration. My audio interface is an ES-9.

I seem to have a similar problem in Windows 10 and Ableton 9 ;). VCV Rack 2 vst annoyance

Hell no - access to core audio and other audio devices from within the Rack VST is probably the single best feature about it!

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CV and audio are the same thing in Rack. It works exactly the same as any other VST with multi-channel outputs in Live.

Have you watched Omri’s video about Rack2 with Live? If not you probably should.

What version of Rack pro are you running? since 2.0.3b I think there are separate templates for Rack standalone and Rack VST - just save a template file that has the DAW driver loaded in the audio module (if Core Audio is giving you problems) and you should be good to go. Everytime you add an instance of Rack VST, it will use that template.

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I have the same problem: As soon as I change the audio driver to CoreAudio and choose ES-9 as a device Ableton audio output stops and the window type of freezes. Critical seems to be the device, not the driver (at least is that the point ableton freezes). Interestingly, the test tone (from within Ableton preferences) still works. My workaround is (as already written): reloading the audio driver in Ableton preferences restores control of Ableton and thus avoids the need to restart Ableton.

Done that, everything is super stable so far. The workaround saves a lot of time. With Rack 2.03b Ableton crash right from the start. I already wrote the bug to the support.

( MacOS 11.6.1 (BigSur) - MacMini M1-AbletonLive Suite 11.0.12-RackPro-2.0.4)

Steve - I only started having this problem with 2.0.3b and now with 2.0.4. The way I was finding it at first was working on a patch in Standalone, and then to open it in the VST version. This is how the settings for audio get set up in a way that screws up the way Live seems to be running. I was freely going back and forth between Standalone patches and VST patches without this problem in 2.0.2.

Also Steve, I’m not sure what you mean about this being the VST’s best feature. Live is using Core Audio on my system to send audio signals to my hardware audio interface. Ableton is responsible for routing any audio signal from itself, from clips, and from plugins out to Core Audio. On my system, if I start with a completely empty rack in the VST in Live, and then create an audio interface module, like Audio 8, and then set it up for the module to route audio to Core Audio directly, instead of to DAW, it instantly freezes Live’s interface. I can’t trigger clips, I can’t start or stop the Transport, I can’t even now start up Push 2 and have it initialize and connect. It seems like the VST rack can still make sound, but Live is crippled. However, if I initialize it to DAW, everything works fine. So I’m not understanding how this is a good feature. Maybe your system is working differently

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The Omri video for Ableton/VCV is a great source. However, all of the Audio Modules in his examples are defaulting to DAW. I believe this always happens when you instantiate a Audio Module in the VST version. If, however, he changed the setting from DAW to Core Audio, my bet would be that his Live interface would freeze. In some of my cases, I loaded a patch from Stand Alone, or from downloading, that had the Audio Module already set to Core Audio on loading the patch. This is what had me going on circles

That would be the safe thing, but ppl didn’t like that limitation, so they opened it up!

I am usually a fan of flexibility. You never know when someone will use something in a cool way that you never could have imagined when you designed it. To be honest, I think I’ve now got a handle on how the audio (and MIDI) is getting in and out of the VST rack in Live. I can consistently now get it to work and can consistently totally hose up Live with specific settings. At this point, I’m wondering if it’s just me, or are other Mac users with similar systems seeing the same thing

User945 - I didn’t answer your post, sorry. I’m not sure that this works the same on Windows, since I’m on a Mac. From what I see is that if I set up the audio using the same settings I would use with VCV 1.1.6 or with VCV 2 standalone with the VST rack plugin, it will freeze Live. So, for me I have to select Core Audio setting in the Audio Module for Standalone, and DAW setting in the Audio Module in the VST

Yes - It was only in 2.0.3 that access to Core Audio from within the VST was added - so if your issue relates to core audio in the VST, it would not have happened before 2.0.3. And then (I think) in 2.0.3b, separate Rack templates for Standalone and VST were added to avoid problems related to the VST loading templates with Core Audio rather than DAW driver enabled by default.

It’s the best feature because it means you are no longer limited to the 16 channels offered by the DAW driver and you can access other devices from directly within Rack VST (sending CV/Audio back and forth to hardware Eurorack for example) without having to bother with sending it to the DAW first and then routing it from there, which can mean having to create DAW tracks dedicated to routing with the right ins and outs to do that. It’s just much quicker, easier and more convenient to do it directly from within Rack.

My system is definitely working differently, which is odd because like you, I’m also on a 2020 iMac running Catalina 10.15.7. I mainly use Bitwig but I just fired up Live to test. My main audio interface in Live is an RME Digiface. In the Rack VST I can switch between DAW driver and Core Audio driver without any problems. When I have Core Audio selected, I can switch between different devices - I can use the same Digiface Live is using or I can go direct to an Audient ID22 that I use for monitoring, or I can select and use an ES-8 - no problem doing any of it.

When you say Live freezes/crashes when you select core audio driver in Rack VST, does it happen immediately on the selection of the core audio driver (and no device at all) or when you try and select a device? If it’s when selecting a device, make sure that device is set to the same sample rate as your DAW and Rack are using. I run everything at 48kHz. When I first tried my ES-8 it would not load because it was set to 44.1 (trying to select it didn’t crash/freeze Live though). All fine after switching it to 48k in Audio Midi Setup.

Steve, thanks for your detailed response. Seeing that you can get it to work, it got me thinking a little more clearly about what might be happening on my end. I just ran a test where I loaded my template which had the Audio 8 defaulting to DAW, and then I chose Core Audio. This time I selected the iMac’s speakers instead of my iConnect interface. Ableton did not freeze and I could monitor clip audio in my headphones. At the same time audio from the Rack VST was coming out of my iMac speakers. It is looking way more like the problem may be with my iConnect driver than anything else. It’s probably not going to be anything I’m ever going to use, but that’s no big deal. I now have a better idea of what’s going on. Now back to the music!

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