Poly.4.L Setup in Bidule 08 Aug 2016

by Industrial Radio


In this post we are going to set up the PRO-4 in Poly.4.L in Bidule using a separate synth per string. Because we are using multiple instances of a synth we are going to show you some tricks in linking parameters so that each synth is controlled by a single, 'master' synth.


For this setup we are going to set the MIDI SEND parameter to 'Poly.4.L'.

When MIDI SEND is set to Poly.4.L the bass will send MIDI data for each string on a separate MIDI channel starting from the channel specified by the parameter MIDI OUT. So, if MIDI OUT is set to '1' the bass will send on MIDI channels 1,2,3, and 4 with MIDI channel 1 being the highest string.

  • MIDI channel 1 - G-string
  • MIDI channel 2 - D-string
  • MIDI channel 3 - A-string
  • MIDI channel 4 - E-string

The rationale is the same for the PRO-5. If the PRO-5 is set to Poly.5.L, the bass is tuned to BEADG, and MIDI OUT is set to '1' the bass will send on MIDI channels 1,2,3,4, and 5 with MIDI channel 1 being the highest string.

  • MIDI channel 1 - G-string
  • MIDI channel 2 - D-string
  • MIDI channel 3 - A-string
  • MIDI channel 4 - E-string
  • MIDI channel 5 - B-string

While it is certainly our goal to allocate a separate MIDI channel and synth for each string it does create the problems that we will have multiple synths all set to receive on different MIDI channels and when we alter the settings on one synth the changes are specific to that instance of the synth. Just imagine the work involved in having to save and load patches into each individual synth and then update the MIDI IN number every time you want to make a minor patch edit.

In the majority of cases we will want the synths to look and feel as much as possible like a single, unified synth. In Bidule we achieve this by using the MIDI Splitter group and by linking the synth parameters.

MIDI Splitter

The MIDI Splitter is a Bidule group file (.bgrp) that takes a single MIDI input and splits each MIDI channel (1-16) into to its own separate MIDI signal and remaps the MIDI data to MIDI channel 1 (download). By doing this all plugins that receive the MIDI Splitter outputs can be set to MIDI channel 1 thus removing the need for having different MIDI IN settings on multiple synths.

Screenshot of MIDI Splitter group within Bidule

The MIDI Splitter outputs go from 1 to 16 (left to right). You will need to connect the MIDI Splitter outputs that correspond to the MIDI channels the bass is sending data on. So, if MIDI OUT is set to '1' the PRO-4 will be sending on MIDI channels 1-4 and you will need to connect each of the first 4 MIDI Splitter outputs to their own separate synth (see picture below).

NOTE: You will need to save the Bidule group file into the correct 'Groups' folder. The directory locations should be something similar to that listed below.
For Mac: Applications → Plogue Bidule 0.9750 (version number will depend on version installed) → groups
For Windows: Users → Username (your username) → AppData → Roaming → Plogue → Bidule → groups

Making the Connections

Below is a screenshot of the completed setup.

Screenshot of completed setup within Bidule featuring u-he TyrellN6

Load all the devices you need and connect them together as per the screenshot.

  1. IR Fretsense port 1 (MIDI Devices → Input → IR Fretsense port 1)
  2. MIDI Splitter (Groups → MIDI Splitter)
  3. 4 instances of the software synth
  4. Stereo Mixer 8 (Mixing → Stereo Mixer 08)
  5. Audio Output (This will vary depending on the user's audio interface setup)

Linking the Parameters

Now the last thing to do is to link the parameters of the synths together.

Rename the synths so that one has a label like 'MASTER' and the others have appended numbers to identify them. I have labelled mine 'TyrellN6 [MASTER]', 'TyrellN6 2', 'TyrellN6 3', and 'TyrellN6 4'.

Click on the 'Parameters' button at the top of the Bidule application to reveal the Parameter panel. There are two columns at the top of the panel: 'Source' and 'Target'.

Screenshot of Bidule Parameters Panel

Link each synth individually by selecting your 'MASTER' synth in the 'Source' column, selecting the target synth in the 'Target' column and then press the 'Link' button. Be careful not to link synths together that have already been linked because it will throw up an error message for every parameter in the list which is pretty annoying.

Once you have linked all parameters to the 'MASTER' synth you will find that when you double click on the 'MASTER' synth to reveal its Graphical User Interface it will force all four synths to open which can be irritating. To solve this we need to unlink the 'Open UI' parameter. You can find this in the list of linked parameters at the bottom of the Parameter panel. Simply find and select the three linked parameters ending in 'Open UI' and click the 'Unlink' button.

Screenshot of Bidule Parameters Panel with Open UI parameters selected

Now you should find that when double click on the 'MASTER' synth that it will only open the user interface for that synth and when you tweak most parameters these changes will occur across all the linked synths.


  • Not all parameters can necessarily be linked. Unfortunately, some synth vendors do not support comprehensive linking.
  • This setup forms the basis of polyphonic Imprint setups.
  • PRO-5 users need to add and link an additional synth.