Noise Engineering Basimilus Iteritas Alter
Six-oscillator analog-inspired digital drum voice
10 HP Eurorack module
Basimilus Iteritas Alter is a parameterized digital drum voice with analog roots, built around six oscillators running in additive or FM configurations with a powerful wavefolder for harmonic shaping. It excels at kicks, snares, hats, claps, and experimental percussion but can also produce leads, basslines, and abstract textures. Its variable sample rate, per-oscillator envelopes, and three synthesis modes give it a wide sonic palette ranging from sub-shaking thuds to metallic alien noise.
Features
- Six-oscillator synthesis engine with three architecture modes: additive, additive with pitch envelope, and phase modulation
- Variable sample rate aligned to harmonics of the fundamental to reduce inharmonic aliasing
- Per-oscillator envelopes controlled by Attack, Decay, and Harmonic parameters
- Infinifold wavefolder with dynamic multi-stage folding and pulse train mixing at extreme settings
- Dedicated noise oscillator mixed via Attack knob position
- Harmonic decay control that individually shapes the duration of each of the six oscillators
- Spread control for tuning oscillators from harmonic to inharmonic intervals
- 1V/octave pitch tracking on Pitch CV input
- Envelope output mimicking internal envelope shape for external modulation
- Manual trigger button on front panel
- Audio-rate triggering supported
- Bass/Alto/Treble range switch with two-octave steps
Controls & Jacks (28)
- Status — Indicates module power status.
- Attack — Adjusts attack time for all oscillators. Left of center adds noise, dead center produces classic analog-style pop, right of center slows att
- Morph — Controls waveform of all oscillators. Blends continuously through sine, triangle, saw, and square. Offsets CV input.
- Pitch CV — Pitch modulation input. Calibrated for 1V/octave. Range: -2V to +5V.
- Morph CV — Waveform modulation input. Knob offsets this CV. Range: 0V to +5V.
- Harmonic CV — Harmonic decay modulation input. Range: 0V to +5V.
- Harmonic — Controls harmonic decay of oscillators. Fully left produces only one oscillator (simple analog bass drum). Increasing adds more harmonics wi
- Fold — Controls infinifold section. First 3/4 of range sets folder threshold with dynamic fold stages. Top quarter mixes in pulse train for additio
- Spread — Controls frequency spacing of oscillators. Allows overtone series to vary from purely harmonic to inharmonic.
- Decay — Adjusts decay time for all oscillators. Offsets CV input.
- Pitch — Adjusts pitch of oscillators. Press and turn for coarse semitone adjustments, or turn for fine tuning. Calibrated for 1V/octave tracking.
- Audio Out — Low-impedance audio output. Output varies based on parameterization with loudness compensation. Up to 14V peak-to-peak.
- Bass/Alto/Treble — Three-position switch changing voice pitch register. Each position offsets pitch by two octaves.
- B/A/T — Envelope output that mimics the shape of BIA's internal envelope. Range: 0V to +5V.
- Spread CV — Harmonic spread modulation input. Range: 0V to +5V.
- Decay CV — Decay time modulation input. Knob offsets this CV. Range: 0V to +5V.
- Trigger — Envelope trigger input. Threshold around +1.8V. Any gate or trigger fires the envelope.
- Fold CV — Fold/wavefolder modulation input. Knob offsets this CV. Range: 0V to +5V.
- Skin/Liquid/Metal — Three-position switch selecting oscillator configuration. Skin: six-oscillator additive for tonal sounds. Liquid: six-oscillator additive wi
- Attack In — Adjusts attack time for all oscillators. Left of center adds noise, dead center produces classic analog-style pop, right of center slows att
- Activity — Indicates envelope activity.
- Treble
- Trig LED
- Trig — Triggers the envelope. Manual button activates envelope. Works at audio rates and accepts any gate or trigger.
- S/L/M cv
- S/L/M
- Attack CV — Attack time modulation input. Knob offsets this CV. Range: 0V to +5V.
- Power
How-To Guides
- Autocalibration
- Simple Kick Drum
- Simple Snare Drum
- Simple Hi-Hat
- Not Quite FM Bass
- Supersaw Synth Lead
- Simple Clap
- Evolving Metallic Texture
- Percussion as Modulation Source
- Pitch-Modulated Kick Variations
Explore the interactive Basimilus Iteritas Alter panel on BleepDex — tap any control to learn what it does.
