Circle Tutorial 9: How To Make An Analogue Underwater Pad

What is Covered?
An intermediate to advanced level tutorial on an creating an analogue underwater pad sound.
Introduces the design of sounds for ambience, that evolved and change over time.


Some of the earlier tutorials recreated classic analogue synth patches that were also very straight forward to program. In this tutorial we'll look at how to create an authentic analogue sound that has a few more modulations going on within it.

This patch is a pad sound featuring an LFO modulation that gives it an 'underwater' feel. It's a pretty useable sound that would be usable with a wide range of musical styles.

Step 1 - The Oscillators.

I wanted to create a pretty harmonically rich canvas on which to build this patch, so i have used three analog oscillators in total, plus Circle's noise generator. Square, saw and triangle waves are used together all with slightly different tunings to create a rich texture.

The Analogue Oscillators And Noise Generator

The noise generator is used in low pass mode and a lot of the top end is filtered off. This adds a slightly dark backdrop to the existing oscillators without being too bright. All the oscillators are then mixed to suitable level using the mixer section.

The Mixer

The Raw Oscillators

Step 2 - Setting up the amp envelope.

The amplitude envelope was programmed with long attack and release times and a small amount of decay. This is basically the dynamic signature of the classic dreamy pad patch.

If you find yourself using a similar setting on a few occasions when building your patches, you can always save it using the drop down menus to the right hand side of each module. This can be a great way to recall settings for any section of Circle and can really speed up programming.

The Classic Pad Amp envelope

The Patch with Amplitude Envelope Applied.

Step 3 - The filter and filter envelope.

I wanted the action of the filter envelope to be a little different to that of the amplitude. The attack and release times are nearly identical but the major difference here is that the decay is longer and the sustain much lower. This creates a downward fade of the filters cut off frequency as the sound progresses.

The Filter Envelope

The filter is then set to low pass mode and a good amount of resonance is dialled in. This emphasises the sweep of the secondary envelope and adds richness by imparting extra harmonics to the sound. If you wanted further crunch and harmonics added at this point you could add a small amount of fuzz distortion, I decided to keep things clean,.

The Filter Settings

The Low Pass Filter Is Applied

Step 4 - The LFO and sequencer.

The bubbly analogue texture in this patch is created by the combination of an LFO and step sequencer effecting the cut off frequency of the resonant low pass filter.

The LFO waveform is a little left field and gives the sound a sort of random quality. This is achieved by mixing two waveforms together. The first is a simple sine wave but the second is a stepped wave, this gives the sine wave a jagged, random feel.

LFO and Step Sequencer

There is also a step sequencer being used here also mapped to the filters cutoff frequency, this is simply to add further variation and interest. You will notice that both the LFO and sequencer are synced so that they will always be in time if used with a sequencer.

The Filter Modulated By Both The LFO And Sequencer

The Final Filter Sound

Step 5 - Adding effects.

To give the patch a little extra boost I have added some chorus and reverb. The chorus gives the patch a nice stereo feel, while the reverb opens things up a fair bit. As always Circle's effects can really enhance a patch and it's worth experimenting with even subtle doses.

Chorus And Reverb Added.

The patch is now complete, this should show how easy it is to put together an authentic analog patch with some relatively advanced modulations.

Overview Of The Final Patch

Final Patch With Effects

Download Tutorial 8 Files

Tutorial 9: How To Make An Analogue Underwater Pad
Download the tutorial in plain text format, the associated audio files and the completed Circle sound/patch.