Review: AALTO: Digital Modular Mania

There's no question that analog synthesis is enjoying a major global renaissance – and for those whose insatiable analog cravings have taken them beyond the classic Roland, Korg and Moog synths we've all come to love, eventually tinkering with modular synthesis seems to be the next step: who hasn't drooled over pictures of custom analog racks made up of boutique individual components patched together with a multi-color birds nest of bantam cable? Problem is, not all of us can afford such lavish gear habits – but if you'd like to replicate a modular synthesis set-up in a fully digital environment, Seattle's Madrona Labs brings you as close as possible with their flagship virtual synth, Aalto.

Coming to Grips

Available in both VST and AU formats, Aalto is designed to replicate the flexibility of modular analog right inside your favorite DAW. The handsome plug-in is divided into four main segments: along the top, the header (Pic 1) allows you to save and switch between presets; the next segment below is the shapes section (Pic 2), which gives you a wealth of options to shape your sounds over time; beneath this is the patcher section (Pic 3), where our virtual bantams become delightfully tangled; and finally, at bottom, the audio section (Pic 4), where signals are generated, filtered, effected and mixed.

Pic 1: The header section

Pic 2: The shapes section

Pic 3: The patcher section

Pic 4: The audio section

The key here is the patcher, which combines the notion of a “modulation matrix” with the infinite routing possibilities inherent in a modular analog setup, allowing any modulation source to be routed to any sound modifier and, in many cases, back again. It's all presented in an elegant, fully re-sizable GUI – and it truly is a graphical interface, with textual elements employed at a minimum in favor of virtual cables that delineate signal flow with intuitive ease and a polished, stylish feel. Add the cleverly integrated oscilloscopes to provide real-time feedback on modulation routings throughout the unit, and it's clear we have an incredibly well-designed instrument on our hands.

Complexity Theory

Critics have already been raving about Aalto's sound quality, and I would concur without hesitation. What makes Aalto's tonality stand out from other great sounding virtual synths is the Complex Oscillator that generates its core signals. Loosely based on an emulation of the infamous Buchla 258 module, its foundation is a two-operator frequency modulation structure based on two oscillators: Modulator and Carrier. Adjusting the timbre control, which smoothly glides through a nonlinear wave folder network resulting in an increasing number of higher harmonics, and the shape control, which adjusts the oscillator curve from a pulse to a sine or saw wave, allows you to easily coax sounds from Aalto that instantly distinguish themselves from more conventionally synthesized patches. Better yet, every single one of these oscillator parameters is available for input from multiple modulation sources via the patcher. 

Guiding the Tides

Another defining component of Aalto's unique sound, also found in the bottom-most audio section, is the Waveguide: a delay with a waveshaper and peaking EQ programmed directly into the circuit. Due to the extremely tight delay times and controllability it offers, it can be commandeered as a waveguide filter or even as an additional oscillator. The delay times can even be tuned to the MIDI notes being played by routing a modulation source from the Key module.

The filter component is modelled on the Oberheim SEM, with a crossfading selector between low-, high-, or band-pass processing; probably my only question with the unit is why the band-pass isn't located between the low- and high-bands here. While it sounds fantastic, the full potential of the filter lies with the extensive modulation options available to control it. The audio section is completed with with a CV-based gate, a unique reverb, and basic mixer settings: volume and panning.

Shape City

Aalto's five primary modulation sources include a key module, a host-syncable sequencer, a potentially self-oscillating LFO, and two envelopes.

The key section translates incoming MIDI signals into useful, routable control signals. For starters, it comes with a bunch of tuning settings; while it defaults to a typical chromatic 12-tone scale, there are a host of included scale options for more exotic tunings – and you can even import other, custom scales using the .scl format. In addition to pitch bend, glide and unison settings, you'll find a number of useful outputs that can be routed via the patcher to control the various elements of Aalto: pitch, velocity, voice, aftertouch, and mod. 

The included step-sequencer is a powerful generative tool, as it can easily sequence both on/off triggers and actual modulation values simultaneously, with a healthy selection of built-in delays, width and glide controls, syncing and quantization options, and a rate control. It's even got a handy step-randomizer, while basic wave shapes can be generated with the touch of a button. All these sequence elements can then be routed to control or trigger various aspects of the synth.The sequencer is so full-featured that we could practically spend the rest of this article focused on it – but then we wouldn't have room to mention the LFO. 

While on the surface the LFO may seem quite simple, it's no less powerful in terms of the unique effects that can be coaxed from it. Perhaps most important here is the noise dial, which sweeps smoothly from a randomized noise waveform to a nice clean sine wave, with a number of useful states between. The LFO is of course sync-able to your host, but when left un-synced, the frequency can be pushed to self-oscillating values for extreme effects.

While the first envelope follows a more-or-less standard ADSR approach, the second envelope is based on a delay-attack-release model with the option to loop it as a sort of second LFO, if you're into that sort of thing.

Patch Adams

While the modules that comprise the core audio generation and shaping capabilities of Aalto are certainly unique, what truly sets it apart is the fully modular patch bay, where seemingly infinite routing possibilities await.

Any parameter that can send a control value has a small output dot bordering the black horizontal zone that functions as the patcher; any parameter that can receive a control value has a slightly larger dial bordering the patcher region that can be adjusted to determine the influence of the control signal routed into it. If you want to determine which parameter an input or output is connected to, simply follow the tidy arrows built into each section of Aalto's design.

To route a control parameter to an input, just click its corresponding output dot and a virtual cable appears in the patch bay; now just drag the other end of the cable to the parameter you want it to control and voila, there you go – all patched in, easy as that! Now it's just a matter of adjusting the input to the desired level and you're free to tweak away.

While most conventional virtual synths are restricted to a fixed amount of modulation routings, the beauty of Aalto is that any control source can be sent to as many inputs as you like – and the reverse is true, with nearly all inputs able to receive from multiple modulation sources at the same time as well. With a number of fantastically unique components included, it's the patcher that brings Aalto closest in line with the expansive horizons of modular synthesis; with a little imagination and just a few tweaks, you'll be creating truly wild sounds you never thought possible before.

Deeper Than Soprano

It's hard to find any fault with this innovative synth. Incredible sound quality, well-designed presets and a fantastic GUI make Aalto a joy to use whatever your knowledge of synthesis might be. Throw in the great user documentation and a bargain price point ($100 USD), and there's no reason Aalto shouldn't be the very first option for anyone looking to explore modular possibilities from the comfort of their chosen DAW. It should also be high on the list for any producers looking for a powerful new addition to their synthesis arsenal at a surprisingly friendly price.

Web: http://madronalabs.com/products/aalto