Intellijel Swells: multi-mode stereo reverb for Eurorack with deep mangling options

Intellijel Swells, announced at SB2025, is a multi-mode stereo reverb for Eurorack with deep mangling options and onboard swelling modulation.

Last year at Superbooth, the Canadian company Intellijel announced several new products, including the Jellymix desktop mixer and an update to their popular 7U case.

Intellijel also teased a new mighty reverb module called Swells, which is now available.

Intellijel Swells

Swells is a new creative stereo reverb module for Eurorack with 96kHz 24-bit audio and 32-bit float internal processing.

Intellijel Swells follows the Sealegs delay module’s design and focuses primarily on faders for the main control parameters, with some additional larger and smaller knobs.

It works in stereo and offers nine distinct reverb models that cover everything from realistic spaces and lush studio FXs to otherworldly and far-out textures

Fog: Sealeg’s classic lush reverb with full control
Blur: the mutant offspring of Multigrain’s built-in reverb.
Shadow: classic dark hall, long corridors, huge spaces.
Velvet: high echo density with fast attack but no metallic ringing
Asterion: a metastable multitap delay, inspired by celestial vintage hardware units of yore
Deadspace: non-Newtonian smearing for the astrally inclined, rending the fabric of space and time.
Buckets: a matrix of variable sample-rate delays, with cruft and crunch intact.
Ritual: hail to this harmonious reverb, octaves, fifths, and spiraling dissonance.
Gaze: inspired by classic nonlinear algorithms with a modern slant

The module gives you uncompromising fader control over each parameter of each reverb model, like pre-delay, size, decay, damping, EBB, flow, and EQ. EBB and flow allow you to fine-tune the character of each model.

Thanks to the faders, these parameters can also be used in a very performance-oriented way.

Mangling Your Reverbs

Swells has the same shaping nature as Multi-Grain or Sealegs, allowing you to completely transform its character with just a few finger twists. This starts already in its core, which usually runs at pristine quality at 96kHz 24-bit audio

However, you can also flip to a dirtier one. With the Lo-Fi switch, you can choose between two Lo-Fi modes that add degradation and other mangling bits to the reverb algorithm for a warm, fuzzy Lo-Fi sound.

Also onboard are Freeze and Reverse effects. The first captures a slice of audio for infinite sustaining reverbs – drone alert. Reverse, on the other side, flips the audio buffer to create unique backward reverb sounds, with multiple time and syncing options.

There is also a burst effect that can create a wide range of sudden noise or feedback bursts. Swells also has a drive effect to add saturation to your input signal, as well as a selectable low-cut filter for taming low-end rumble.

Swells also features its namesake Swell generator. It consists of a multi-mode envelope follower with rise, fall, and threshold controls, allowing you to derive useful control signals from the input signal, the output signal, or a dedicated Sidechain input.

Since the swell generator is normalled to all reverb parameters by default, you can bring in a lot of complex animations and dynamics without connecting a modulation source.

Control & Connect

Each of Intellijel Swells’ parameters can be tweaked manually or with a dedicated CV input with attenuverters, making it a versatile reverb playground for knob/fader twisters or automation friends.

Further, you have a trigger input with which you can trigger various parameters (swell, freeze, burst, o reverse) synchronization, perfect for mangling the reverb textures rhythmically.

Clever, there are also send and return modes, allowing you to use it as a send effect.