# Ctrldev driver - how to bypass audio processor in chain? \[SOLVED\]

**URL:** <https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095>\
**Category:** Development\
**Created:** [May 4, 2026, 6:44pm UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095 "2026-05-04T18:44:55Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![shieman](https://discourse.zynthian.org/letter_avatar_proxy/v4/letter/s/7993a0/32.png) [@shieman](https://discourse.zynthian.org/u/shieman)\
**Post date:** [May 4, 2026, 6:44pm UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095/1 "2026-05-04T18:44:55Z")

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Hi

For a Ctrl Driver,

What is the function to call to bypass an audio processor in a chain ?

Thanks

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**Author:** ![tunagenes](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/tunagenes/32/7279_2.png) [@tunagenes](https://discourse.zynthian.org/u/tunagenes)\
**Post date:** [May 5, 2026, 6:49am UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095/2 "2026-05-05T06:49:11Z")

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Hi @shieman - I don’t know the answer to your specific question, but I do have some pointers that hopefully will help, you may already know this stuff, anyways:

You’re probably going to use a Callable UI Action, or CUIA. You’ll find quite a few results from searching the Wiki and-or this Discourse for CUIA, including:

> **[3.1 CUIA: Callable User Interface Actions - Accessing Zynthian from your...](https://wiki.zynthian.org/index.php/Accessing_Zynthian_from_your_computer#CUIA:_Callable_User_Interface_Actions)**
>
> The CUIA is an unidirectional remote API that can be used to send simple control messages to zynthian UI. The CUIA can be accessed in several ways, as described in the user's guide and this section explains how to access the CUIA using OSC on port...

after that list in the Wiki, it says:

You can see the details in the [Zynthian UI’s source code](https://github.com/zynthian/zynthian-ui/blob/3ce8a5e0f22d4007a5460f61869678b5c78d6f69/zyngui/zynthian_gui.py#L1132)

The function might not exist yet because that area is so new, so you might have to add it or request it.

I hope that is helpful.

And, on May 4th, May the Force be with you.

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**Author:** ![shieman](https://discourse.zynthian.org/letter_avatar_proxy/v4/letter/s/7993a0/32.png) [@shieman](https://discourse.zynthian.org/u/shieman)\
**Post date:** [May 5, 2026, 8:22am UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095/3 "2026-05-05T08:22:46Z")

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Thanks

I do not think it is the right direction, but i will look at.

Thanks very much

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**Author:** ![HansR](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/hansr/32/15102_2.png) [@HansR](https://discourse.zynthian.org/u/HansR)\
**Post date:** [May 6, 2026, 7:55am UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095/4 "2026-05-06T07:55:01Z")

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Hi @shieman,

> [@shieman](#):
>
> I do not think it is the right direction

I don’t think so too.

To understand what a ctrldev driver does, you can take a look at [this post from @jofemodo](https://discourse.zynthian.org/t/chord-analyzer-and-other-plugins-by-dusk-audio-now-installable-for-zynthian/12996/35).

It has helped me enormously to understand the different parts of the chain.

Kind regards,  
Hans.

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**Author:** ![jawn](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jawn/32/14487_2.png) [@jawn](https://discourse.zynthian.org/u/jawn)\
**Post date:** [May 6, 2026, 8:28am UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095/5 "2026-05-06T08:28:42Z")

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You can do almost anything from a ctrldev driver - the driver is the glue to your MIDI device.

And what you can do is only limited by the API, e.g. CUIA but can be more, that is available in Zynthian.

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**Author:** ![jofemodo](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jofemodo/32/2_2.png) [@jofemodo](https://discourse.zynthian.org/u/jofemodo)\
**Post date:** [May 6, 2026, 9:03am UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095/6 "2026-05-06T09:03:51Z")

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In order to bypass an AUDIO processor you have to access the “bypass” controller from the processor. Given you already have the processor object, let’s say the object variable is called “proc”:

`proc.controllers_dict['bypass'].set_value(1)`

Be warned that some processors use different names for the bypass controller: BYPASS, Bypass, ByPass

Kind regards,

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**Author:** ![shieman](https://discourse.zynthian.org/letter_avatar_proxy/v4/letter/s/7993a0/32.png) [@shieman](https://discourse.zynthian.org/u/shieman)\
**Post date:** [May 6, 2026, 5:02pm UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095/7 "2026-05-06T17:02:23Z")

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Oh thanks a lot Jofemodo

I did it yesterday but that did not work, i wonder if i need to do an update of the processor ?

Thanks

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**Author:** ![shieman](https://discourse.zynthian.org/letter_avatar_proxy/v4/letter/s/7993a0/32.png) [@shieman](https://discourse.zynthian.org/u/shieman)\
**Post date:** [May 6, 2026, 5:04pm UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095/8 "2026-05-06T17:04:35Z")

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Thanks HansR

I will read that post i did not see.  
Cause i did a lot ‘reverse’ search in the different files to understand existence of controllers\_dict…

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**Author:** ![shieman](https://discourse.zynthian.org/letter_avatar_proxy/v4/letter/s/7993a0/32.png) [@shieman](https://discourse.zynthian.org/u/shieman)\
**Post date:** [May 6, 2026, 5:25pm UTC](https://discourse.zynthian.org/t/ctrldev-driver-how-to-bypass-audio-processor-in-chain-solved/13095/9 "2026-05-06T17:25:35Z")

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Ok it’s working, i had a variable error…

Thanks !