Ginette - DIY instrument based on the ondes Martenot

I designed and built this instrument during 2010-2011. The idea is based on the ondes Martenot that was invented by Maurice Martenot in 1928. My instrument is named 'Ginette' after Ginette Martenot - an ondist and the sister of Maurice Martenot. She played ondes Martenot at the premiere of Olivier Messiaen's Turangalîla-Symphonie.

The heart of the instrument is a voltage-controlled oscillator (VCO) that produces the sound. I found great VCO design from Music From Outer Space -website. The VCO produces four waveforms or timbres - sine, triangle, ramp and square - which can be selected on the panel. The range of the fingerboard is four octaves and on the panel there is an octave selection knob, so the total pitch range is nine octaves. In practice the tracking isn't so accurate in very high and low registers. There are connectors for an external CV and a gate, so the instrument can also be controlled using external device like a keyboard or a sequencer, which both are my future DIY projects. I am going to improve the instrument by adding a voltage-controlled amplifier (VCA). This would fix the problem with the volume control button that leaks some signal when it's supposed to be mute.

The background noise in the video is due to the tube amplifier.

Here's the link to MFOS VCO:
http://www.musicfromouterspace.com/analogsynth/VCO20090724REV0/VCO20090724REV...

Dana Countryman's ondes Martenot controller project inspired me to start my own project. Here's the link:
http://www.danacountryman.com/martenot_project/martenot.html

Thanks to: Ray Wilson and Music From Outer Space, Dana Countryman
Special thanks to: Heta, Mikko, Teemu

Category:

Music

Tags:

• DIY
• electronic
• instrument
• ondes
• Martenot
• French
• Connection
• synth
• synthesizer
• Olivier
• Messiaen
• Radiohead
• MFOS
• VCO

[Sup3rmassiveDeadStar]

How much did it costed to build?

[pemakini]

@Sup3rmassiveDeadStar I haven't count the total cost for the instrument. I had an opportunity to use tools that I don't own, like a milling machine, and some materials too, for free. In the end I think the major investment was the time for designing and building the instrument.

[TheMagebear]

I don't think a lowpass filter would remove all the noise from a pot, even for control voltage use. The original Ondes useds a leather bag filled with carbon powder as a pressure sensitive variable resistor. Have you considered using something like quantum tunneling compound or some other pressure sensitive substance to produce a control voltage?

[pemakini]

@TheMagebear I'm not familiar with the pressure sensors. Since the expression button is built around the certain linear position sensor, it would be quite complex task to replace it with a different kind of sensor. The linear position sensor is working nicely at the moment. If it's getting old some day, it's relatively cheap to replace, less than ten euros. If I need to build the same kind of structure in the future projects, I'll consider also the pressure sensor.

[pemakini]

@TheMagebear The original volume control design sounds very interesting, I didn't know about it. Do you happen to know what kind of sensor is in the expression button of the French Connection? Or the pitch control structure in the ondes Martenot? I haven't found much technical information of those instruments.

[PitBullFrankfurt]

Wow, amazing project! It's so expressive, it really doesn't need a filter, though one would be cool too. How much did it cost to build? Jatka samaan malliin =)

[pemakini]

@PitBullFrankfurt Thanks! I haven't counted the total cost, but the main thing was insistent working and opportunity to use workshop and tools that I don't own.

[TheMagebear]

Don't forget the the Ondes is a hetrodyned instrument same as the Theremin. It will only take a small change in capacitance or inductance to alter pitch.

I don't think the builders of the French Connection are about to tell us their secrets and don't forget that the Ondes is still protected by copyright and so on.

I think your instrument is brilliantly done and yes I will be building something similar myself. Thanks for showing us to aspire to.

[TheMagebear]

There are two seperate systems of pitch control. The keyboard uses fixed inductors, one for each key, and variable inductors, one per octave. The variable inductors are used for the vibrato effect, their cores held steady whilst the coils are attached to the keyboard which is mounted to allow side to side movement.

The ribbon acts as a variable capacitor. Each octave has a pair of parallel plates and the ribbon has a piece of metal that slides between them changing the capacitance.

[pemakini]

@chrisjhart221138 Thank you. I'll let you know! How much would you pay for it?

[pemakini]

@TheMagebear The variable element in the expression key is the linear position sensor that is basically a linear potentiometer.