Shruti-1 | Mutable instruments
http://mutable-instruments.net/
Digital oscillators
Available for all oscillators, and band-limited
* impulse train (high-pass filtered square wave) with pulse-width modulation
* square with pulse-width modulation
* triangle with waveshapping
* sawtooth with waveshapping
Available for oscillator 1 only
* sawtooth with sweepable resonance (casio cz-like). This creates a resonance directly in the oscillator output, without using the filter
* simplistic FM (1>2 configuration), with adjustable modulation index and frequency ratio
* 8bit-like harsh waveforms with wavetable scan
* poor man’s square with pulse-width modulation (plenty of aliasing but fat for basses)
* colored noise (sweep from low-pass filtered white noise -> white noise -> high-pass filtered white noise)
* lo-fi vowel synthesis (think “speak and spell”) with vowel morphing
* wavetable (16 waveforms) with wave morphing, for drones
* “sweep” oscillator which scans through all the band-limited waveforms
Mixer
* adjustable oscillator balance
* mixing algorithms: simple sum, simple sum with synchronization, ring modulator, xor modulator
* extra sources: noise & sub-oscillator (triangle or square)
Filter
* CEM3379 analog VCF/VCA, with external audio input
Modulation
* LFOs: 2, with square, sawtooth, triangle, sample & hold shapes. Syncable to tempo
* envelopes 2 ADSR
* modulation matrix: up to 14 source -> destination connections. Adjustable modulation amount in the -100% — 100% range
* modulation sources:
o LFO 1/2
o step sequencer
o arpeggiator gate
o mod. wheel
o pitch bender
o DC offset
o CV inputs 1/2/3
o noise generator
o ENV 1/2
o note velocity
o note number (eg for filter tracking)
o keyboard gate
* modulation destinations:
o filter cutoff
o VCA gain
o pulse width/Parameter osc. 1/2
o pitch osc. 1/2
o vibrato (fine pitch, applied to osc 1 & 2 simultaneously)
o oscillator balance
o noise level
o subosc level
o resonance
Performance
* step sequencer: 16-steps (4-bits value per step). Adjustable cycle length
* arpeggiator: 15 rhythmic patterns, each of them with up/down/up&down/random variants. 1-4 octave range
* clock: internal, 40-240 BPM with swing, or external (MIDI)
* tuning: alternative tuning schemes/keyboard mappings: pythagorean scale, just temperament, 1/4 tone on E/A/B, Melakarta ragas
* “patch performance”: custom page in which 4 user-selectable parameters can be assigned to the 4 editing pots
System and memory
* MIDI implementation: notes, controllers, clock synchronization, patch editing by NRP, individual patch load/save by SysEx
* patch memory: 16-patches stored in EEPROM
* easter egg
* firmware update by SysEx
Hardware and connectors
* power: 2.1mm connector, requires 7.5V-9V 300mA supply (can be unregulated). Center pin positive (+), outer collar negative (-)
* audio input/output: 6.35 Jack (Mono audio out), 6.35 Jack (External signal in)
* cv inputs: 3 CV inputs (0-+5 V, labelled “HACK_ME!” on the PCB) for easy experimentation with controllers, accessible through pin header on the motherboard
* MIDI: in, out (logical thru + patch dumps)
* serial: tx/rx/reset pins for interfacing with an usb->serial chip, for on-chip firmware development
* controllers:
o 12 facade LEDs (current page / modulation matrix visualization)
o backlit 2×16 LCD display
o 4 pots for patch editing
o volume and input gain pot
o 5 navigation switches, one inc/dec switches pair
115 euro
