# Cubase loads stereo plugins on mono tracks

**URL:** <https://iplug2.discourse.group/t/cubase-loads-stereo-plugins-on-mono-tracks/581>\
**Category:** Uncategorized\
**Created:** [28 February 2022 05:48 UTC](https://iplug2.discourse.group/t/cubase-loads-stereo-plugins-on-mono-tracks/581 "2022-02-28T05:48:27Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![RexMartin2](https://avatars.discourse-cdn.com/v4/letter/r/da6949/32.png) [@RexMartin2](https://iplug2.discourse.group/u/RexMartin2)\
**Post date:** [28 February 2022 05:48 UTC](https://iplug2.discourse.group/t/cubase-loads-stereo-plugins-on-mono-tracks/581/1 "2022-02-28T05:48:27Z")

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For some reason Cubase 10 will load my stereo (2-2 only) plugins on _mono_ tracks.

When inserted on mono tracks both VST2 and VST3 plugins load but:

- The VST2 version IsChannelConnected(ERoute::kInput, 1) and IsChannelConnected(ERoute::kOutput, 1) both return “false” - which I can use to tell the plugin to process in mono.

- The VST3 version IsChannelConnected(ERoute::kInput, 1) and IsChannelConnected(ERoute::kOutput, 1) both return “true” - and the plugin (wrongly) thinks it’s a stereo track.

This is a problem because some of my plugins should only be used/appear on _stereo_ tracks (which is why I specified “2-2” and not “1-1 2-2” in config.h).

Other DAWs and other formats (AAX and AU) do not load (or even show) my stereo plugins on mono tracks - so this seems to be a “Cubase thing”.

Are these known issues in Cubase, especially with VST3? Any workarounds/hacks?

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**Author:** ![RexMartin2](https://avatars.discourse-cdn.com/v4/letter/r/da6949/32.png) [@RexMartin2](https://iplug2.discourse.group/u/RexMartin2)\
**Post date:** [28 February 2022 17:17 UTC](https://iplug2.discourse.group/t/cubase-loads-stereo-plugins-on-mono-tracks/581/2 "2022-02-28T17:17:46Z")

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Some additional info regarding VST3:

If I define my plugin as “1-1 2-2” in config.h and insert the plugin on a mono track in Cubase, IsChannelConnected(ERoute::kInput, 1) and IsChannelConnected(ERoute::kOutput, 1) both return “false” - which is correct. However, If a sidechain is added to the config - like “1.1-1 2.2-2” - the routing is again, reported wrong on mono tracks.

If I define my plugin as “2-2” in config.h and insert the plugin on a mono track in Cubase, IsChannelConnected(ERoute::kInput, 1) and IsChannelConnected(ERoute::kOutput, 1) both return “true” - which is wrong.

So it seems there is something not quite right in iPlug2’s VST3 I/O - at least in Cubase for some reason. It works properly in other DAWs so maybe this is a _Cubase_ bug? It’s hard to believe the creators of the VST3 spec would get it wrong so this is baffling.