Sleep Machine / SM-1 In development

Analog noise
for the bedside.

Continuous analog sound with adjustable tone and movement.

Four knobs control Body, Air, Movement, and Volume. A walnut enclosure houses the speaker and circuitry, with brass controls on the front.

Try the sound model

Sound generated by analog circuitry, without recordings.

Sleep Machine prototype on a workbench, with a light enclosure, black front panel, four brass knobs, and a brass top button
Prototype shown; final enclosure in solid walnut.

01 / The listening room

Try the controls.

Adjust the controls while listening. The graph shows the modeled tone response and the spectrum of the playing noise.

SLEEP MACHINE / SOUND MODELLoading sound model…
Tone response / 20 Hz–20 kHzTone · ref 2kNoise off· relative dBMovement
Tone response and live noise spectrumA solid brass-colored curve shows the modeled Body, Air, and Movement response. A translucent gray spectrum underneath shows the actual playing noise. The gold tone curve is referenced to its level at 2 kHz; the noise spectrum is normalized to its own peak. Every control uses the same 20 Hz–20 kHz frequency range and +12 to −24 dB scale. The light-blue overlay follows the selected control: modeled tone changes for Body or Air, drifting boost and cut for Movement, or a flat playback level for Volume. Body and Air show changes from their minimum settings, referenced to 2 kHz. Movement shows each wet path mixed with the dry signal, relative to dry alone. The gold curve combines both paths, including their phase interaction. Volume shows playback level relative to maximum. The curves remain visible when sound is off.+12+60−6−12−18−2420 Hz1001k20k+−
Body50%
BrighterDarker

Adjust the overall tonal balance.

Air50%
DarkerBrighter

Adjust the high-frequency content.

Movement25%
OffMore

Set the depth of the moving filters.

Volume25%
LowHigh

Adjust the playback level.

Adjust your device volume for a comfortable listening level.

The interactive sound model uses digital circuit simulations to approximate the sound of Sleep Machine’s analog circuitry. The physical sound will also depend on component tolerances, calibration, and the speaker and enclosure response.

02 / Beneath the surface

The signal path.

The circuit generates noise, filters it, and adds slowly changing frequency bands. Select a stage for its circuit details.

01 / Source

Continuous analog noise.

Sleep Machine generates noise electronically and filters it before it reaches the tone controls. The sound is continuous, with no recorded loop.

The source uses noise from a reverse-biased transistor junction. A gain stage amplifies it, and a passive resistor-capacitor network reduces high-frequency energy before the tone controls. The network approximates a pink-noise balance.

03 / Build notes

Design and prototyping.

Sound studies, circuit design, and physical prototypes shaped the controls and enclosure.

Bitwig Studio sound study showing a noise spectrum, modulation controls, and broad EQ bands

01 / Sound-design study - Bitwig Studio screenshot

Sound studies in Bitwig.

Bitwig experiments established the initial control scheme and the use of broad, slowly changing EQ bands. These studies guided the analog circuit design.

Early noise-machine breadboard prototype connected to a small speaker on the studio workbench

02 / Physical prototype - studio photograph

Testing on a breadboard.

The breadboard prototype combined a transistor noise source, filters, and a speaker for listening tests. Breadboard Studio mapped connections and supported simulation and assembly.

KiCad rendering of the latest analog circuit board with a corridor for the top buttonInspect board ↗

03 / Circuit board - KiCad render

Laying out the circuit board.

The circuit board fits around the speaker and controls. It brings the noise source, filters, amplifier, and power latch into a single assembly.

CAD cutaway of the Sleep Machine enclosure showing the speaker, circuit board, and control placementView cutaway ↗

04 / Enclosure design - CAD cutaway

Designing a bedside instrument.

The enclosure arranges the controls within reach and houses the speaker, circuit board, and wiring. Physical prototypes helped establish the proportions, control spacing, and button access.

04 / Product details

Details.

Model
SM-1
Sound source
Continuous analog noise
Controls
Body, Air,
Movement, Volume
On / off
Top button
Speaker
Built-in
Enclosure
Solid Walnut
Hardware
Solid Brass
Power
12 V DC
App required
No
Internet required
No