# VST3 Builds but Does Not Pass Audio; Yet AU Works fine **URL:** \ **Category:** General JUCE discussion\ **Created:** [March 8, 2022, 9:58pm UTC](https://forum.juce.com/t/vst3-builds-but-does-not-pass-audio-yet-au-works-fine/50527 "2022-03-08T21:58:45Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![alisonbma](https://avatars.discourse-cdn.com/v4/letter/a/67e7ee/32.png) [@alisonbma](https://forum.juce.com/u/alisonbma)\ **Post date:** [March 8, 2022, 9:58pm UTC](https://forum.juce.com/t/vst3-builds-but-does-not-pass-audio-yet-au-works-fine/50527/1 "2022-03-08T21:58:45Z")
Has anyone had an issue with VST3 in JUCE where it builds successfully but does not pass audio; yet the AU executable does pass audio? I can verify this problem is not just that of my own project. I tried compiling one of the built-in JUCE NoiseGate modules and ran into the same problem. ---
**Author:** ![reuk](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/reuk/32/21494_2.png) [@reuk](https://forum.juce.com/u/reuk)\ **Post date:** [March 8, 2022, 11:07pm UTC](https://forum.juce.com/t/vst3-builds-but-does-not-pass-audio-yet-au-works-fine/50527/2 "2022-03-08T23:07:11Z")
How are you testing the plugin? Which host are you using, and on which platform? ---
**Author:** ![alisonbma](https://avatars.discourse-cdn.com/v4/letter/a/67e7ee/32.png) [@alisonbma](https://forum.juce.com/u/alisonbma)\ **Post date:** [March 8, 2022, 11:47pm UTC](https://forum.juce.com/t/vst3-builds-but-does-not-pass-audio-yet-au-works-fine/50527/3 "2022-03-08T23:47:07Z")
I’m on MacOS Catalina 10.15.7, using XCode to build from Projucer, testing on Ableton Live 10 and Live 11. Some of my colleagues on MacOS ran into the same issue as I did. I had another colleague who had no problems with the VST3 on Windows. ---
**Author:** ![t0m](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/t0m/32/16413_2.png) [@t0m](https://forum.juce.com/u/t0m)\ **Post date:** [March 9, 2022, 10:52am UTC](https://forum.juce.com/t/vst3-builds-but-does-not-pass-audio-yet-au-works-fine/50527/4 "2022-03-09T10:52:46Z")
There’s nothing particularly unusual about your combination of OS and DAWs, so it’s very hard to see what could be going wrong. Could you please try the AudioPluginDemo? [JUCE/AudioPluginDemo.h at master · juce-framework/JUCE · GitHub](https://github.com/juce-framework/JUCE/blob/master/examples/Plugins/AudioPluginDemo.h) Otherwise [pluginval](https://github.com/Tracktion/pluginval) might provide a little more information, or the Test Host in the VST3 SDK: [3rd-party developers support & SDKs | Steinberg](https://www.steinberg.net/developers/) ---
**Author:** ![reuk](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/reuk/32/21494_2.png) [@reuk](https://forum.juce.com/u/reuk)\ **Post date:** [March 9, 2022, 11:06am UTC](https://forum.juce.com/t/vst3-builds-but-does-not-pass-audio-yet-au-works-fine/50527/5 "2022-03-09T11:06:33Z")
> [@alisonbma](#): > > I tried compiling one of the built-in JUCE NoiseGate modules and ran into the same problem. Note that this plugin is designed to only pass audio when there’s a trigger on the sidechain input. It would be expected for the plugin to produce silence in the absense of a sidechain input. I was able to see audio appearing at the output in Live after adding an active sidechain input. I’d echo what @t0m said, and suggest trying out a few more of the JUCE demos. The DSPModulePluginDemo is a fairly standard effect plugin with stereo input and output, so that’s probably worth trying out. ---
**Author:** ![alisonbma](https://avatars.discourse-cdn.com/v4/letter/a/67e7ee/32.png) [@alisonbma](https://forum.juce.com/u/alisonbma)\ **Post date:** [March 9, 2022, 9:06pm UTC](https://forum.juce.com/t/vst3-builds-but-does-not-pass-audio-yet-au-works-fine/50527/6 "2022-03-09T21:06:13Z")
Got it, thanks all for the help! The problem was that the prepare to play function was being called multiple times which broke the audio graph, but it is resolved now.