Aalto is a new semi-modular software synthesizer with an innovative, patchable UI, distinctive sounds, and a charming personality. It is out now as an Audio Unit plugin for MacOS X. Aalto’s sound engine lets you create sounds that have been difficult or impossible to make with softsynths before now. The heart of Aalto is a Buchla-inspired complex oscillator, with FM, timbre and waveshape controls that enable a wide range of expressive sounds. These sounds are uniquely malleable and alive, in part because they are made with dynamic calculation, not static wavetables.
Aalto is designed as much for sequencing patterns as for playing individual notes. Each voice has a separate, built-in sequencer with a patchable, independently controllable rate and offset that make it easy to achieve evolving, chaotic textures.
Each voice also includes a lowpass gate module with a vactrol emulation in the control path. The vactrol equation slows down the response to incoming control signals through a complex nonlinear filter. You can turn the vactrol response down to instantaneous, or up to a pronounced ring.
Following the lowpass gate is a patchable waveguide / delay module with a waveshaper and a peaking EQ built into the feedback loop. Because it has such short and controllable delay times, unlike a typical analog delay, it can be used as an additional oscillator or waveguide.
Aalto’s filter is a state-variable topology with mixable simultaneous outputs, tuned to have a similar range to an Oberheim SEM filter. (Though I couldn’t resist turning up the resonance just a little more.)
Subjectively speaking, Aalto can make a wide range of sounds, from lush to edgy, including some very complicated ones, without sounding too thick in a mix. Aalto’s sounds are not hyped or confined, they are wide-range, open and natural. This approach will appeal to experienced sound designers who have their own favorite EQs and limiters. And for those just getting into synthesis, Aalto is an accurate and honest tool for learning. Madrona Labs have tried to make Aalto a deep instrument that will reward lasting engagement.