Isobar Industries - Serratus

Serratus is a stereo resonator and sound processor built around comb filtering, feedback and a rather extensive collection of ways to mess with your sounds. Nine different comb algorithms cover clean pitched delays, resonators based on physical modelling and more abstract spectral processing, paired with nine mutation algorithms for saturation, distortion and various forms of digital destruction — one of them even adapts JPEG compression to audio. Yes, JPEG compression. Feed Serratus a drum hit and it can turn it into a ringing metallic object; give it something sustained and it can pull out pitched resonances, smear it into a drone or push the feedback until it starts breaking apart into something far more unhinged. The comb and mutation engines can be stepped through or morphed between, so the transition from one algorithm to the next can be blended smoothly rather than happening as an abrupt jump.

The panel itself looks appropriately strange, with peculiarly named controls such as Ebb, Flow, Rend, Bind, Etch, Melt and Leech, but there is a reasonably logical system underneath the terminology. Ebb and Flow shape what the comb rings with and how it behaves, while Rend and Bind determine how hard and in what manner the mutation stage gets involved. Pitch spans ten octaves with 1V/oct tracking and can alternatively follow clock divisions and multiplications. Feedback is bipolar, moving from inverted to positive feedback, while Orbit introduces stereo cross-feedback and phasing inside the loop. Matter changes the decay of the resonances from dark and heavily damped towards a brighter, harder-edged response. Then you have the mutation stage, Etch filtering and Melt reverb, and each of these can independently sit before the comb, inside its feedback loop or after it. Distorting a resonator after the fact is one thing; repeatedly feeding that distortion back through the resonator is another. Moving the filter or reverb into the loop has similarly large consequences, so rearranging these blocks can take the same basic sound from fairly restrained to completely mangled.

There is plenty going on internally to keep all of this moving. Leech is an onboard modulation engine for the module’s macro parameters: turn it left for fast, irregular random movement, or right for slower, wandering modulation. An envelope follower can derive another modulation signal directly from whatever you feed Serratus. Freeze captures and loops the buffer, opening it up to scrubbing, detuning, drift and sustained textures. Extensive CV control lets you animate many of its parameters from elsewhere in the rack.

Serratus is undoubtedly deep, but its basic proposition is actually quite easy to grasp: choose how the sound resonates, decide how badly you want to mistreat it, then decide what gets thrown back into the feedback loop and in which order. This is an exciting one — a very capable resonator with enough strange ideas and unruly feedback behaviour to keep revealing new sounds for quite a while.

Features:

• Stereo comb resonator, mutation processor and feedback engine
• Nine comb algorithms ranging from pitched delays to physical modelling and spectral processing
• Nine mutation algorithms including saturation, digital destruction and JPEG compression adapted for audio
• Algorithm stepping and continuous morphing
• Ebb and Flow controls for shaping comb-resonator behaviour
• Rend and Bind controls for mutation intensity and character
• Comb pitch spanning ten octaves
• 1V/oct pitch tracking
• Alternative clock mode with selectable clock ratios
• Bipolar positive and negative feedback
• Orbit stereo cross-feedback and phasing control
• Matter damping control from dark/Rubber to bright/Crystal responses
• Etch processing with selectable DJ-style filter or 16-band filterbank
• Adjustable filter resonance / filterbank Q
• Stereo Melt reverb with dark Ore and pitch-shifting Aer modes
• Mutation, filter and reverb independently routable before, inside or after the feedback loop
• Leech internal modulation engine with chaotic and organismic behaviour
• Internal envelope follower with assignable modulation bus
• Envelope follower CV output
• Freeze buffer with live scrubbing, detuning, drift and sustain
• Dry/wet mix and input level controls
• Extensive CV control plus Freeze gate input
• Daisy Patch SM processing core
• 48kHz / 32-bit floating-point processing