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Reverb + ?

Lo-fi spring reverb

A little reverb for the Pocket Operator. Very lo-fi.

  • Analog audio
  • PCB design
  • 3D printing
Reverb + ? preview

A spring behind the sound

I love making beats and sounds on my PO-33, but I kept missing one effect: reverb. So I built a miniature spring reverb to clip onto the back.

A bone conductor drives the spring, and a sliding piezo disc picks up the vibrations. Moving the disc back and forth produces a flanger-like effect. The short spring gives it a distinctly lo-fi shimmer.

The custom PCB connects through the Pocket Operator’s headphone jack and shares its two AAA batteries, so there is no need for an extra power supply. A single slider on the front blends the dry and wet signals. The ABS and PLA enclosures are 3D-printed, with small pops of color.

The project received an honorable mention in Teenage Engineering’s PO10DIY contest.

In detail

Reverb + ?, view 2
Reverb + ?, view 3
Reverb + ? — The finished unit
The finished unit
Reverb + ? — The finished unit, another view
The finished unit, another view
Reverb + ? — Pocket Operator and potentiometer
Pocket Operator and potentiometer
Reverb + ? — Power connections
Power connections
Reverb + ? — Extension spring attached to the piezo disc
Extension spring attached to the piezo disc
Reverb + ? — Effect slider and headphone output
Effect slider and headphone output
Reverb + ? — Bone conductor soldered to the PCB, with power from the Pocket Operator
Bone conductor soldered to the PCB, with power from the Pocket Operator
Reverb + ? — The input jack also secures the board to the Pocket Operator
The input jack also secures the board to the Pocket Operator
Reverb + ? — Reverb + ? detached from the Pocket Operator
Reverb + ? detached from the Pocket Operator
Reverb + ? — Honorable mention on Teenage Engineering’s website
Honorable mention on Teenage Engineering’s website

Materials & credits

Materials & components
PCB, extension spring, bone conductor, piezo disc, headphone jacks, potentiometer, PLA, ABS, metal plate
Recognition
Honorable mention, PO10DIY contest

Out in the world.