Cabinet design - fpga-theremin/theremin GitHub Wiki

This article describes classic theremin cabinet design suitable for most of analog and digital theremin projects.

Easy to reproduce - plywood laser cut based, "plumbing" antenna mounts.

Form factor

I like Moog Etherwave Theremin (EM Theremin) form-factor.

  • It's familiar for every thereminist.
  • Space inside cabinet is enough for fitting almost any hardware.
  • Mic stand mount is must have.
  • DIY wooden cabinet is easy to build and inexpensive

Antennas

"Plumbing" style antennas solution like in etherwave (with gas/water fittings, and copper tubes) is easy to build.

Cover

  • LCD touch screen
  • Optional speaker(s) may be useful sometimes

If you don't need LCD, edit InkScape design file.

Front panel controls / sockets

  • It makes sense to place headphone connector with volume pot on front panel
  • 1-2 encoders and 2-3 pots would be enough for implementing rich set of controls
  • Some button(s) and/or LEDs - not sure if they are helpful if there is LCD touch screen

Rear panel controls / sockets

  • Audio Line Out - for connecting amplifier (doesn't it make sense to add to mono, mono + stereo, or stereo only outputs?)
  • Audio Line In - stereo input, e.g. for aux accompaniment input
  • Power input socket
  • Power switch
  • USB input for FPGA board programming can help to avoid removing cover when programming
  • Optional USB OTG may be used to interface with PC - e.g. as USB MIDI or USB HID device
  • Ethernet - not sure if it could be useful
  • Several sockets to connect foot buttons and/or pedals - e.g. may be used to control some effects and loop feature

Plywood laser cut technology

  • Plywood looks as cheap but good solution.
  • Making laser cut design simplifies building of cabinet. Less work, better result.
  • Glue + a few screws - easy to assemble.

Laser cut design file for 8mm birch plywood:

Cabinet laser cut design

If you don't need screen on top cover, just edit design with InkScape and remove rectangle hole and mounting holes from cover.

NOTE: antenna mounting holes are too small for 1/2" fittings. They should be 20-21mm instead of 19mm diameter.

Trying to assemble - checking if all sizes are correct:

Check if all details fit each other

Pitch antenna side:

Pitch antenna side

With cover:

With cover

Polish surfaces to remove burned stains:

Polishing

Glue side walls and legs:

Glue side wall details

Glue angle details on cover for centering cover:

Cover centering angles

Wooden bars at corners to screw cover to:

Cover angles

Assembled and polished. Comparing with Etherwave.

cabinet glued and polished

Dark color, varnished:

colored varnished

Designing front and back panels

Use aluminum angle profile 40x20x2mm.

panels and antenna mounts

Mic stand mount

Use 3/8" mic stand mount from Atlas Sound:

mic stand mount

cabinet bottom view

Mounting antennas

Cabinet has holes for 1/2" mounts.

Use fittings for 10mm 50cm chromed copper/brass water pipes.

antenna pipe side 1 antenna pipe side 2

cabinet with antennas

Mounting Waveshare 4.3" LCD on cabinet cover

TODO...