http://mutable-instruments.net/shruti1
Specifications
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 (32 waveforms) with wave morphing. Waveforms were extracted from organ/digital piano sounds
•“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:
◦LFO 1/2
◦step sequencer
◦arpeggiator gate
◦mod. wheel
◦pitch bender
◦DC offset
◦CV inputs 1/2/3
◦noise generator
◦ENV 1/2
◦note velocity
◦note number (eg for filter tracking)
◦keyboard gate
•modulation destinations:
◦filter cutoff
◦VCA gain
◦pulse width/Parameter osc. 1/2
◦pitch osc. 1/2
◦vibrato (fine pitch, applied to osc 1 & 2 simultaneously)
◦oscillator balance
◦noise level
◦subosc level
◦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:
◦12 facade LEDs (current page / modulation matrix visualization)
◦backlit 2×16 LCD display
◦4 pots for patch editing
◦volume and input gain pot
◦5 navigation switches, one inc/dec switches pair
Specifications
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 (32 waveforms) with wave morphing. Waveforms were extracted from organ/digital piano sounds
•“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:
◦LFO 1/2
◦step sequencer
◦arpeggiator gate
◦mod. wheel
◦pitch bender
◦DC offset
◦CV inputs 1/2/3
◦noise generator
◦ENV 1/2
◦note velocity
◦note number (eg for filter tracking)
◦keyboard gate
•modulation destinations:
◦filter cutoff
◦VCA gain
◦pulse width/Parameter osc. 1/2
◦pitch osc. 1/2
◦vibrato (fine pitch, applied to osc 1 & 2 simultaneously)
◦oscillator balance
◦noise level
◦subosc level
◦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:
◦12 facade LEDs (current page / modulation matrix visualization)
◦backlit 2×16 LCD display
◦4 pots for patch editing
◦volume and input gain pot
◦5 navigation switches, one inc/dec switches pair
