Anushri is a monosynth like no other. In addition to its analog VCO/VCF/VCA and digital modulation sources, it includes a fun and immediate note sequencer with step-by-step recording, and a gritty 8-bit drum machine with a truly original control interface. Just like its elder sister the Shruthi-1, Anushri is not designed for industrial assembly but is instead sold as a kit – you can assemble it, modify it, expand it and service it without any specialized expensive equipment. Open source firmware and schematics give you full access, control and ownership of its circuitry and code.
Raw analog power…
Anushri’s audio generation and processing chain is analog. The main sound source is a VCO with sawtooth and pulse-width waveforms, coupled with a sub-oscillator – a simple formula that made the success of the Roland SH-101 and MC-202. Following the VCO comes a multimode VCF, whose 12dB/octave slope provides a refreshing change from the rounder and cleaner 24dB/octave Moog-style filters. The band-pass and high-pass modes provide additional filtering flavors. Anushri’s secret weapon of sonic destruction is a switchable fuzz circuit inserted between the VCF and VCA – which bring a heavy dose of nasty distortion.
… with a digital twist
We did what no other synth manufacturer dared trying before: enrich the VCO with an auxiliary digital oscillator, which can be used as a FM source, a sync signal generator, or – if you don’t mind having some digital signal flow in the audio chain – an additional detuned audio source for fattening the VCO sound. This brings many of the sonic benefits of a dual-VCO setup, while keeping the construction simple enough for a DIY project.
Analog synthesizer with primary VCO and secondary digital square oscillator
- Saw-core VCO with temperature compensation and accurate tracking over 5 octaves.
- Optional software-controlled tuning to increase stability and accuracy.
- Sawtooth and square waveforms, with adjustable pulse-width and pulse-width modulation.
- Waveform mixer.
- -1 or -2 octaves sub-oscillator with adjustable level.
- Secondary digital square oscillator (2.5 MHz programmable interval timer) available as a linear FM source, a VCO sync signal, or an additional audio source sent to the mixer along with the VCO.
- Mixer with external audio input.
- 12dB/octave multimode filter (LP/BP/HP), with sine-wave self-oscillation.
- Post-filter overdrive/fuzz circuit.
- Linear VCA.
Digitally controlled modulation sources
- 1 main ADSR routable to pitch, pulse-width, cutoff frequency. Segment time: 1ms to 12s.
- 1 simple 1-parameter envelope (morphing through various stages, including the shape of the main ADSR, and a rigid “GATE” style envelope) routed to VCA.
- Velocity routed to either cutoff frequency of VCA gain (adjustable level).
- 1 LFO routable to pitch, pulse-width and cutoff frequency ; with 8 waveforms (triangle, square, ascending and descending ramps, S&H, bernouilli process, piecewise linear random process, noise). Frequency: 0.06 Hz to 100 Hz. Syncable to arpeggiator/sequencer clock.
- 1 triangle LFO for vibrato and/or growl controlled by the modulation wheel.
- CV Resolution: 16-bit internal, 12-bit external, 2.45kHz refresh rate.
Arpeggiator and sequencer
- Arpeggiator with 4 modes (up, down, up&down, random) ; 1 or 2 octaves ; 6 patterns and “acidity” setting adding accents/slides. Latch/hold mode.
- SH-101-style note sequencer with step by step recording, up to 128 notes. Along with notes, rests, ties, glides and accents can be recorded.
- Tempo set by internal clock (40-240 BPM) with shuffle, external MIDI clock or external 6/12/24 ppqn trigger.
- Keyboard transposition of sequence during playback.
- Algorithmic drum pattern generator using an innovative “pattern sculpting” approach. Drum patterns are “sculpted” with 5 knobs.
- Drum sounds can be freely triggered from an external sequencer using MIDI channel 10.
- x0x-style programming from a MIDI keyboard to override the algorithmic pattern generator.
- Digital sound synthesis of analog-style BD / SD / HH sounds with tone control.
- Audio resolution: 10 MHz, 1-bit (equivalent to 8-bit, 39kHz).
Mutable Instruments are getting ready for a release on November 4th.