The underside of the instrument, showing the hidden pulleys, 10-turn pot, and tension spring.



The Volume control section.

With cover on, and Q125 Signal Processor module installed.
The blue cables carry the pitch signal in and out, and the black and orange cables carry the audio in and out.
I replaced all the original single-turn pots with 10-turn pots, for better fine-tuning.

The finished Martenot Controller.
The keyboard (although it can be played), is really mainly there for visual reference,
when sliding the Ring which is anchored to the center of the string.
(click photo for more detail)


Another view of the finished instrument. I used a small piece of pvc pipe for the ring,
with some black Velcro inside it , to snug it tighter to my finger.
(click photo for more detail)


New Modification:
I put together a dedicated module system, JUST for the Martenot.
This way, I don't have to tie up my whole modular synth with a patch for the Martenot:

Future Modifications:
1) I plan to add a foot pedal on the floor, for adding overall
volume dynamics, in additon to playing the volume (articulation) button on top.
(I've since done this... works great!)

2) I'm considering adding a trigger microswitch, so that when I depress the hand volume button,
it sends a signal to my big synth for adding special effects.

3) I'm also considering adding an additional slider pot to the lever mechanism,
that will be able to sweep a filter, at the same time as when the volume button is being depressed.
This could add variable brightness, when playing some notes louder than others.

Quite a lengthy discussion about my instrument has been taking place at
I've joined in the discussion, and shared a lot of info here.

Extreme thanks must go to my father, Darrell Countryman, who painstakingly built this instrument to my specs.
I wouldn't have it, without him. Also, thanks to Roger Arrick, Morbius and Lorin Parker for their technical advice.

View the YouTube video, Part Three.

Other YouTube Videos:
You might be interested in viewing my first YouTube video,
featuring an early (but different) prototype of the Martenot.
Click here.

My second YouTube video (getting closer, design-wise) is here.

The four single-sheave pulleys were purchased from Edmunds Scientific.

Potentiometers: Three 100-K, 10-turn pots were used in this project. All three replaced the original pots of the Q125,
that I mounted near the volume button, and deep inside the instrument. You can buy the pots online from Mouser Electronics here.

String: 1mm nylon sash cord (used for Venetian blinds) was purchased at my local Pacific Fabrics store.

Ring: I cut a piece of 3/4" pvc pipe for the finger ring, purchased from Lowes' Hardware.

Spring: The tension spring was also purchased from Lowe's.

Wood: I purchased about $50 of nice 3/4" and 3/8" oak from Lowe's, as well.

Volume Control: The volume control section was taken from a Rogue VP-201 volume pedal for guitars. These pedals seem to be discontinued now.

All in all, I'd estimate my materials costs to be about $150 - not counting the Q125 signal processor from

FYI, I am not in the manufacturing business. I encourage you to build your own.
Let me know if you do!

- Dana

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