1. Architecture Overview
DRC is a virtual analog polysynth — it models the behavior of classic hardware analog synthesizers in software. The signal flow follows traditional subtractive synthesis: oscillators generate raw waveforms → filters shape the harmonics → amplifier controls the volume → effects add space and character. Understanding this signal flow is understanding every analog synth ever made.
2. Oscillator Section
- Oscillator 1 & 2: Each oscillator generates a waveform:
- Sawtooth: All harmonics present — bright, rich, aggressive. The most versatile waveform. Leads, basses, pads, brass — sawtooth does everything.
- Square/Pulse: Only odd harmonics — hollow, woody, reedy. Classic video game sound. Pulse Width Modulation (PWM) thins or widens the waveform for evolving timbral animation.
- Triangle: Very few harmonics — soft, pure, flute-like. Excellent for sub-bass and gentle leads.
- Sine: Single frequency, no harmonics — the purest possible tone. Sub-bass foundation, test tones, FM modulation carrier.
- Noise: All frequencies at random amplitudes — white (bright, hissy) or pink (darker, warmer). Percussion, breath, texture, sweeps.
- Tuning per oscillator: Octave (coarse, ±4 octaves), Semitone (chromatic, ±12), Fine Tune (cents, ±100). Detune Osc 2 slightly from Osc 1 (5-15 cents) for analog-style width and warmth.
- Oscillator mix: Balance between Osc 1 and Osc 2. Center = equal blend. Hard left/right = solo one oscillator.
Sub Oscillator
- Generates a tone one octave below Osc 1. Always tracks the keyboard pitch.
- Adds low-end weight and body to bass patches. Mix to taste — subtle for foundation, heavy for chest-hitting sub-bass.
- Uses a sine or square waveform. Sine = clean sub. Square = fuller, more harmonics.
Noise Generator
- Mix white or pink noise into the oscillator blend. Adds breath, air, and percussive texture.
- Through the filter: filtered noise creates sweep effects (rising/falling noise), wind textures, and hi-hat-like transients.
3. Filter Section — Dual Filters
Ladder Filter (Moog-Style)
- Modeled after the iconic Moog transistor ladder filter — warm, creamy, musical resonance. THE filter sound that defined analog synthesis.
- Modes: Low-pass (removes highs — warmth, darkness), High-pass (removes lows — thinning, brightness), Band-pass (isolates a band — wah, nasal, telephone).
- Cutoff: The main frequency control. Turn down on LP = darker. Turn up = brighter. Automate for sweeps.
- Resonance: Boost at the cutoff frequency. Low = subtle coloring. High = pronounced peak. Maximum = self-oscillation (the filter generates its own sine wave). The resonance character is what makes the Moog filter legendary — it sings.
Multimode Filter
- More clinical and versatile than the ladder. LP, HP, BP, Notch (removes a specific frequency band — creates a hollow, phaser-like character).
- Selectable slope: 12 dB/octave (gentle rolloff) or 24 dB/octave (steep, aggressive cutoff). 12 dB for subtle shaping, 24 dB for dramatic filtering.
Filter Controls (Both Filters)
- Envelope Amount: How much the filter envelope opens or closes the filter on each note. Positive values = filter opens on note-on (bright attack that darkens). Negative values = filter closes on note-on (dark attack that brightens). This is how you create plucky, evolving, breathing filter sweeps per note.
- Key Tracking: Makes the filter cutoff follow keyboard pitch. Without it, high notes sound muffled because the filter stays fixed. With full tracking, brightness stays consistent across the keyboard range.
4. Modulation — Envelopes, LFOs, Mod Matrix
3 Envelopes (ADSR)
- Amp Envelope: Controls volume over time. This shapes WHEN the sound plays and for HOW LONG.
- Fast Attack + short Decay + zero Sustain = pluck/stab (piano, marimba, percussion).
- Slow Attack + full Sustain + long Release = pad/wash (strings, ambient).
- Medium Attack + medium Sustain + medium Release = natural instrument (guitar, organ).
- Filter Envelope: Controls filter cutoff over time. This shapes HOW THE TONE EVOLVES per note.
- Fast Attack + short Decay = bright pluck that darkens (the "bwow" — bass synth staple).
- Slow Attack = filter sweep that opens gradually (builds and risers).
- Free Envelope: Assignable to ANY destination via the mod matrix. Pitch (pitch bend on note-on), pan (auto-pan per note), oscillator mix (timbral shift), LFO rate — anything. This third envelope adds animation that the first two don't cover.
3 LFOs (Low Frequency Oscillators)
- LFOs generate slow cyclic waveforms that modulate parameters continuously:
- Shapes: Sine (smooth), Sawtooth (ramp), Square (on/off switching), Sample & Hold (random steps — robotic, glitchy), Random (smooth random).
- Rate: Speed of the cycle. Slow (0.1 Hz) = gentle evolution over seconds. Medium (1-5 Hz) = vibrato, tremolo. Fast (10+ Hz) = FM-like buzzy effects.
- Tempo sync: Lock LFO rate to BPM. 1/4 note, 1/8, 1/16, dotted, triplet. Rhythmic modulation that follows the song.
- Common routings: LFO → Pitch = vibrato. LFO → Filter Cutoff = wah/wobble. LFO → Volume = tremolo. LFO → Pan = auto-pan. LFO → Osc Mix = timbral cycling. LFO → PWM = pulse width animation.
Modulation Matrix
- Any source → any destination with adjustable depth.
- Sources: Envelope 1/2/3, LFO 1/2/3, Velocity (how hard a key is pressed), Key Tracking (which note is played), Aftertouch (pressure after initial strike), Mod Wheel (CC1 from MPK Mini IV).
- Destinations: Osc 1/2 pitch, Osc mix, Filter 1/2 cutoff, Filter 1/2 resonance, Amp level, Pan, LFO rate, Effect parameters.
- Examples: Velocity → Filter Cutoff (play harder = brighter). Mod Wheel → Filter Cutoff (sweep with hardware control). LFO 2 → Osc 2 Pitch at slow rate (detuning drift). Aftertouch → Filter Resonance (press harder for resonant peak).
5. Arpeggiator
- Modes: Up (ascending), Down (descending), Up-Down (bounce), Random (unpredictable). Each creates a different melodic character from the same held chord.
- Octave range: 1-4 octaves. Higher = wider melodic range from a single chord hold.
- Gate: How long each arp note plays relative to the step. Short gate = staccato plucks. Long gate = legato connected notes. 50% = standard spacing.
- Tempo sync: Lock to BPM. Note values: 1/4, 1/8, 1/16, 1/32, triplet. 1/16 at 120 BPM = fast, driving arpeggio.
- Hold mode: Press keys → release → arp continues playing. Free up hands for knob tweaking while the arpeggio runs.
6. Effects
- Delay: Stereo echo with time, feedback (repeat count), and mix (wet/dry). Sync to tempo for rhythmic echoes. Creates space and rhythmic complexity.
- Reverb: Simulates acoustic space — room, hall. Decay time, damping, mix. Adds depth and dimension. Short reverb for presence, long for atmospheric wash.
- Chorus: Thickens sound by adding detuned copies. Rate and depth controls. Essential for making single-oscillator patches sound full and wide. Classic Roland Juno chorus effect.
- Effects are applied post-filter, pre-output within DRC. When loaded as a VST, the host DAW's effects chain processes DRC's output for additional processing.
7. Cloud Preset Sync
- Create a free Imaginando account in the app settings.
- Save any preset to the cloud → it appears on every device logged into the same account.
- The workflow: Design a bass patch on the phone during a commute → save to cloud → open DRC on the PC in the studio → the same patch is there, ready to use in a Cubase or Ableton project. Zero file transfer.
- Browse community presets uploaded by other DRC users worldwide. Learn from how others design sounds.
8. MIDI & DAW Integration
Mobile (Standalone)
- USB MIDI: connect MPK Mini IV via OTG → play DRC as a standalone synth instrument. All keys, pitch wheel, mod wheel, velocity active.
- Can also be hosted inside compatible mobile DAW hosts.
PC (VST/AU Plugin)
- DRC runs as a VST or AU plugin inside any desktop DAW — Cubase, Ableton, Bitwig, Cakewalk, FL Studio, Logic.
- Load on an instrument track → play from MPK Mini IV or program MIDI → DRC generates the audio → process through the DAW's effects chain and mixer.
- Full automation: automate any DRC parameter from the DAW's automation lanes. Filter sweeps, LFO rate changes, oscillator mix — all recordable as automation.
MIDI Learn
- Long-press (mobile) or right-click (PC) any on-screen knob → "MIDI Learn" → move a knob on the MPK Mini IV → they're linked permanently.
- Map filter cutoff to Knob 1, resonance to Knob 2, LFO rate to Knob 3, osc mix to Knob 4, delay mix to Knob 5 — now 5 hardware knobs control 5 sound-shaping parameters in real time. Performance-ready.
9. Quantize, Transpose, Looping
Quantize & Transpose
DRC is a synth instrument, not a DAW — quantize and transpose happen in the host:
- Standalone mobile: Play and record performances in a separate app. Quantize and transpose in that app.
- As VST in a DAW: The DAW handles all MIDI quantize and transpose. Cubase's Key Editor, Ableton's piano roll, Bitwig's note editor — use the host's tools.
Looping
- Arpeggiator as loop: DRC's arpeggiator creates repeating melodic patterns from held chords. Hold a chord → the arp plays a looping sequence. This IS DRC's internal loop mechanism.
- In a DAW: Record DRC's MIDI output → loop the MIDI clip in the DAW's timeline. DRC generates sound, the DAW handles structure and looping.
10. Pro Tips — The Kokumo Method
- Start with presets, then dissect. DRC has 400+ factory presets. Load one that sounds close to what's needed → study the oscillators, filter settings, envelope shapes, and mod matrix routings. Then modify. Then build from scratch. Reverse-engineering presets is the fastest way to learn synthesis.
- The ladder filter IS the character. DRC's Moog-style ladder filter is the soul of every patch. Learn to use it — sweep the cutoff, adjust resonance, set envelope amount. The filter is the voice. Everything else is the body.
- Cloud sync is the killer feature. Sound design work never trapped on one device. Phone → PC and back. Design on the couch, produce at the desk, perform on stage. Same patches everywhere.
- MIDI Learn for live control. Map the MPK Mini IV's 8 knobs to DRC's most important parameters. Physical knob control transforms DRC from a screen instrument into a performance instrument. Sound design becomes physical.
- DRC as VST in your main DAW. Same synth engine, same presets, same cloud — but inside Cubase, Ableton, or Bitwig with full automation, effects chain, and mixing tools after it. The mobile version is for sound design. The VST version is for production.
- Modulation is life. A static patch is a dead patch. Add subtle LFO to filter cutoff (0.5 Hz, low depth) and the sound breathes. Add velocity to filter and the sound responds to touch. Add envelope to pitch and notes have character. Modulation is the difference between a preset and a living instrument.