01 Voltage 80 · Voltage 78 · Substance

Three instruments. Built from the circuits up.

Voltage Drums is one purchase with three separate plug-ins. Load Voltage 80 for 16 synthesized drum voices, Voltage 78 for a connected preset-rhythm machine, or Substance for monophonic bass synthesis.

Current specificationCompare all three Deterministic Voltage 80 rendersTake the interactive tour
  • Voltage 80: sixteen voices, fourteen individual buses plus the stereo main
  • Internal sequencer with host sync; tempo and swing are adjustable
  • Eight kits and twenty-four curated patterns
  • Substance: 2 oscillators plus sub and noise into a ladder filter
  • 3 verified formats: CLAP / VST3 / Audio Unit
Voltage 80 drum machine interface
Voltage 8016 voices · sequencer · 14 individual buses + stereo main
 Voltage 78 rhythm machine interface preview
Voltage 7814 circuits · 15 trigger choices
 Substance monophonic bass synthesizer interface
SubstanceMono bass synth · 10 presets
15Voltage 80 buses: 14 individual + stereo main
24curated Voltage 80 patterns
8Voltage 80 factory kits
±12 stcontinuous kick tuning
3verified plug-in formats

02 The approach

The behaviour lives in the circuit.

Voltage Drums begins with documented electrical behaviour. The service manual and schematic define the circuit; published analyses settle specific loading questions. Component values go in. Behaviour comes out.

The kick drum’s click comes from the pulse-shaper network in the original Roland TR-808 circuit. A capacitor feeds 2 resistors through a clamp diode, and a closed-form Wright-omega equation solves that network for each sample. The tom’s pitch bend follows the hardware diode pair: pitch rises when the resonator swings hard, then falls as the ring damps. The snare rattle starts as a rectified noise burst and passes through the hardware envelope topology.

Textbook component math puts the kick’s resonator at 45.7 Hz; the published loading analysis says the surrounding resistors pull it up to 49.5 Hz. The model adopts the loaded value, and the documented reference unit rings within six cents of it. The surrounding circuit determines that loading.

Real units fill gaps in the manuals. Hardware recordings set the pitch and decay laws. Separate fits cover spectral balance. Accent response has its own measurements.

Take the kick circuit apart
Bass drum pulse shaper, bridged-T resonator and measured pitch trajectory
The Voltage 80 kick, component by component.Modelled on the Roland TR-808; vector schematic plus deterministic engine measurement.

03 What is in the machine

Voltage 80 has 16 voices

The kit starts with bass drum and snare. Six tuned tom or conga voices fill the middle; dedicated percussion circuits cover the cymbal and open/closed hats.

  • BDBass drum
  • SDSnare drum
  • LTLow tom
  • MTMid tom
  • HTHigh tom
  • LCLow conga
  • MCMid conga
  • HCHigh conga
  • RSRimshot
  • CPHandclap
  • CBCowbell
  • CYCymbal
  • OHOpen hat
  • CHClosed hat
  • MAMaracas
  • CLClaves
See every control and MIDI note

04 The circuit analysis

We read the service manuals so the models cannot lie.

These 6 circuit details change the rendered audio. Each one has a direct test in the synthesis engine.

CV 01

Accent starts as trigger voltage

The service manual gives a trigger-height chart for each voice. On nonlinear circuits, a bigger pulse reshapes the sound: the kick diode network changes its click, while the tom pitch bend reaches farther.

BUS 02

Hats and cymbal share 6 oscillators

The same square-wave bank also feeds the cowbell. Closed hat terminates the open-hat envelope through the hardware ENVELOPE SHUT OFF block. The sources remain connected.

BD 03

The kick contains 3 pitch circuits

Its attack jump comes first, retrigger injection follows the next pulse, and the slow pitch sigh has a separate path in both the circuit model and its tests.

CP 04

Four envelope events make the clap

Three fast recharges open a VCA on the shared noise bus. A final discharge follows. The long tail uses another envelope.

CB 05

Cowbell uses 2 detuned squares

The taps sit at 540 Hz and 800 Hz in the 6-oscillator bank. Its filter and envelope give that shared source the cowbell response.

NOISE 06

One noise source feeds the board

The original circuit used a reject transistor in avalanche breakdown, so the model routes one seeded source to the noise-driven voices and tests the resulting correlation.

808 signal path showing trigger and accent voltage, resonator voices, shared noise and metallic oscillator buses, hat choke and mix
One trigger bus. Shared sources. A real choke.Every line is a connection the engine actually makes.

05 Measurements

The numbers behind the sound.

Every method and toleranceOpen the technical dossier
Kick pitch trajectories overlaid at six sample rates
RATE MATRIX

One specification covers 6 sample rates

Pitch, level and decay are conformance-tested at 44.1, 48, 88.2, 96, 176.4 and 192 kHz. Pitch drift budgets use cents.

Two deterministic renders and their difference at true digital silence
DETERMINISM

The render is bit-identical

A pinned seed reproduces the same output. Block size can change. Event boundaries can move. The bits remain equal.

Model kick decay anchors compared with measured hardware references
GROUND TRUTH

Hardware measurements set the laws

Tests hold the kick fundamental, decay and tone laws to measured sweeps. Shell balance has its own fixture. Snappy taper is separate. Other checks pin tuning curves and metallic frequencies. The hat decay curve closes the set.

Level-normalized spectra showing the timbral change produced by accent
ACCENT CV

Accent reaches the spectrum

The comparison uses 2 engine renders of the kick. After level normalisation, the stronger accent still changes the spectrum because it drives the diode network harder.

06 The engineering

Rust keeps the audio thread boring

The audio callback has fixed work. Its contract permits 0 allocations and 0 locks. It also permits 0 spawned threads. The panic budget is 0; runtime transcendental calls are 0. Source audits check those limits on each build.

audio_thread.guaranteesPASS
allocations          0
locks                0
threads              0
panics               0
transcendentals      0

design_math          f64
coefficients         checked f32
filter_state         f64
denormals            flushed
seed                 pinned
block_partition      bit exact

A source audit rejects forbidden operations in the processing path. Filter coefficients are prepared before the callback. Nonlinear stages use approximations with measured error bounds.

The synthesis engine is a dependency-free Rust core with fixed-size audio state. New machines supply circuit data to those same primitives.

There are 0 recorded one-shots in the sound engine. Each hit is synthesized when you play it. The installer does not need a sample library or content pack.

Voltage Drums architecture from reusable circuit primitives through voice families and complete machines
Primitives → families → voices → machines.Each machine follows the same circuit model. Calibration fixtures and the real-time contract are shared.

07 Formats and availability

Load each instrument directly

Voltage Drums installs Voltage 80, Voltage 78 and Substance as separate plug-ins. Each comes in CLAP / VST3 / Audio Unit.

01 / AVAILABILITY

Choose the instrument in your host

Load Voltage 80, Voltage 78 or Substance directly. Bitsnacks Vending Machine installs all three with one Voltage Drums purchase.

02 / RUST CORE

The callback contract reaches every wrapper

Rust gives the engine fixed-size data and strong types. There is no garbage collector. Automated source checks cover the processing path.

VERIFIED FORMATS CLAP · VST3 · Audio Unit Separate plug-ins in each format
INSTRUMENT STATUS Voltage 80 · Voltage 78 · Substance

Current compatibility and installation details appear in Bitsnacks Vending Machine before installation.

08 The line-up

Meet the instruments

Voltage 80 is the drum machine. Voltage 78 handles preset rhythms; Substance supplies monophonic bass.

Voltage 80, Voltage Drums' drum machine modelled on the Roland TR-808
Modelled on the Roland TR-808

Voltage 80

The machine has 16 synthesized voices and an internal sequencer. Its factory bank contains 8 kits. There are 24 curated patterns. Kick tuning is continuous, and 14 individual circuit buses sit beside the stereo main.

Explore Voltage 80
Preview artwork for Substance, a transistor-ladder bass companion
Included with Voltage Drums and Voltage Synths

Substance

Substance is a monophonic bass synth with 2 oscillators. Sub and noise sources feed a driven multimode ladder filter. MIDI response is expressive; the factory bank has 10 presets.

Explore Substance Hear the Substance demos

09 Hear it. Trace it. Check it.

Hear the circuits. Inspect the measurements.

The tour plays deterministic engine renders. A selected voice reveals its circuit family; measurements sit beside the behaviour they test.

Voltage 80 · circuit and proofTour Voltage 80 Voltage 78 · voices and routingTour Voltage 78