sidechain compression - eurorack modular

 Sidechain compressors.

 

Compressors are essentially devices used to make loud sounds softer.

They enable a producer to boost the level of a track, thus narrowing the dynamic range.

This type of compression is evenly applied to the tack

 

Side Chaining is a more active type of compression.

It's sometimes referred to as "ducking".

It is a type of compression where the volume level of one instrument is controlled by the volume level of another instrument. 

That is, the compressor is only triggered when certain sounds appear.

This is the pumping effect  you often hear in electronic dance music.

Here, the compression level on a bass track is controlled by the output volume of a kick or snare drum.

The Bass line volume drops every time the kick is heard.

Another example of its use is when a song suddenly drops in volume when a radio announcer speaks.

 

 Daft Punk - Indo Silver Club (Official Audio)

 

Thus for side chaining, we need an external signal to act as the trigger.

 

To build your own side chain compressor using a eurorack system

we need a 

1. drum source 

2. Baseline

3. VCA

4. EG with an inverted output

 

The EG could be replaced with a Envelope follower & an inverter.

 

 

In this case, the VCAs gain needs to be turned up.

The baseline is passed through the "open" VCA.

Everytime the kick sounds, it triggers the envelope generator.

The inverted CV lowers the volume of the VCA 

 

These two videos are really good to watch.

  

 

They use the MATHs module

 

 

 

This second video is esp good

 

This is my usual setup.

 

 

I'm using the the Make Noise Function instead of a Maths.

I like to set Rise to full anti clockwise & Fall to about 11 0'Clock to get a ducking effect. 

A fast attack & a slower decay. 

Play around with these settings to adjust the amt of ducking.

The bubblesound VCA is set to expo and CV in to around 3 0'Clock

The Doepfer A-171-2 VC slew Processor works very much like Maths and Function

 

 

It's mostly a licensed copy of Ken Stone's vcs (voltage controlled slope)

 which is in turn based on the Serge vcs.

 

The VCS is a really useful module. Quite versitile.

In this instance it's being use as a voltage controlled envelope generator with an inverted output.
The top and bottom pot are the most important parameters to adjust.