Oscuro · Viroid
Oscuro Viroid turns a 37-key controller into a virtual-analog synthesizer built for serious sound design: wavetables, a deep modulation matrix and a rack of twenty effects.
Free firmware for the M-Vave SMK-37 Elite and compatible models. Tested on the SMK-37 Pro, Donner Starrykey-37PLAY and EROK MKE-P37.
Sound
The voice
Oscillators with sync and FM, a sub and noise, ring modulation, two filters in four routings, saturation, four envelopes and three LFOs. Unison goes up to six voices. Eight knobs and four faders stay under your hands, with an editor page for everything else.
The waves
Wavetable, Wave PWM, Grain and Formant oscillator modes, with 99 tables to sweep through. HyperSaw stacks up to nine detuned saws on an oscillator when you want a wall of sound.
The patches
Load whole Virus banks of A, B, C and TI patches, arpeggiator settings included. They live in four banks of 128, recalled from the keyboard or by Bank Select and Program Change over USB MIDI, and any bank can be saved back out to a file to share or keep safe.
The rack
Twelve familiar studio effects and eight of our own. Delay and reverb play as the Virus patch stored them, and the EQ is the Virus's own three bands. Chain up to six, as sends or as inserts, and watch each new one draw what it does as you turn the knobs.
The familiar twelve: Delay, Chorus, Flanger, Phaser, Tremolo, Distortion, Wah, Filter, Compressor, Reverb, Bit-crush and EQ.
Play
Up to 32 steps with a level for each, a gate per step in percent and ties between notes. Patches bring their own arpeggiator settings with them.
Six slots, forty sources and more than ninety destinations that already sound. Aim wheels, pressure, velocity, envelopes and LFOs at the filter, the oscillators or the mixer, and chain routes: one slot can modulate how much another one does.
Eight knobs and four faders for the sound, two wheels for the feel. Hold mode keeps a chord sounding, so both hands are free for the knobs.
Tune and connect
Most of what the keyboard does is a setting. Trade speed for sound, or sound for speed, and wire it into the rest of your studio.
Record the synth as a stereo 48 kHz input, or play your computer's audio through the keyboard's headphones. USB Out has its own mix, and by default only the synth is in it, so the computer's sound never loops back.
Send clock, start, stop and continue to the rest of your gear. Following an incoming clock over USB is still in testing.
Choose how fast the keyboard reads its keys and pads: the quickest response, or fewer scans and more time for the synth. Key release and pad sensitivity are yours to set as well.
Run the processor from the stock 360 MHz up to 420 MHz for more voices and effects. Heavy patches may need a step back, so it is a setting, not a gamble.
How many notes sound at once depends on the patch, the effects, the modulation and the clock speed. Max Voices, Audio Block and the HyperSaw limit let you decide what gives way first.
The keyboard shows up as “SMK-37 Oscuro USB” with its own USB identity, so a DAW script that looks for M-Vave's device name may need a small edit. Scripts that speak Oscuro's own protocol also get track and clip colours on the pads, the track name on the display and knobs that report how fast they turn.
Putting Oscuro on your keyboard changes one area of its memory, and every step can be reversed. Flashing still carries risk, so keep the keyboard plugged in until it restarts.
The keyboard's boot code, your settings and its calibration stay exactly as they are.
M-Vave's own firmware can be put back, from Oscuro or from any M-Vave version.
The installer never touches your data.
Hold Globe while switching on to skip optional extras such as the faster clock.
Online or local, in a few minutes, and every step can be undone.
