Expressiveness and Ondes Martenot

I was digging around youtube learning about the Ondes Martenot last night, and loved the expressiveness of the “Touche” or “Lozenge” played with the left hand. It controls the volume envelope seperate from the note selection, like the bow of a violin or the breath of a trumpet. The artist quickly goes between soft swells and percussive bird chirps:

I was just wondering, does anyone know what sensor/mechanism Martenot used here? The springiness looks just right. I’m making my own MIDI controller and hoping to work in some monophonic expressiveness (I’d like to make an MPE controller in the future, but taking baby steps for now). I’m thinking I could add a Lozenge and transmit the expression as a MIDI aftertouch message with 7 or 14 bits of resolution.


you mean the touche?

apparently original it was a small leather bag, but now they use things like pressure sensors.

if you want this kind of feel, probably best to look at how the expressive-e touche is made…
this is a modern equivalent, with a really nice feel to it, and super sensitive.
the touche appears to use a pivot action with some springy ‘cylinders’ that provide the resistance.

the expressive-e website doesn’t mention what material the cylinders are made out of, but does have some close up pictures of them (in the spare parts section)

definitely, the feel is pretty important when building these kind of controllers, its an area that these designers spend a lot of time on (Theres an interesting video on the Continuum about this log search for correct materials)


Thanks for the resources Technobear! Wow that video of the Ondes teardown is great but unfortuntely the camera doesn’t get a good look at the piezoresistive bag mechanism! You can see it a tiny bit though.

I think this might be the Lippold Haken interview you mention. I’ll check it out after work

Hello! I thought I’d make an account to do my best to help you with this. The inimitable technobear has provided good insight, and kindly linked to my website :wink:

I think it would be worth adding that the powder touche is not employed in any modern ondes musicales.

Martenot’s instruments used the powder bag, and it feels incredible to play, but modern instruments use various alternative means to varying degrees of success. Things such as force-sensitive soft potentiometers (Ondomo), capacitive metal systems (Dierstein), and hall-effect magnet sensor systems (Ondéa) can certainly do the job of making an effective volume controller. Emulating the ‘feel’ and behaviour of the powder touche is another game, really.

Each of those three systems and the particular ways in which they are implemented represent a different approach to that sort of emulation!

I’ve played a few Martenot instruments, a Mk. 1 Ondéa, a few Dierstein instruments (including my own) and every single one has felt different either due to human manufacturing quirks or to the instrument being altered to suit the player.

It’s a big subject!


Hi Josh! I’m glad to see your chime in. I saw some of your responses in my googling on this topic.

Sounds like everyone has used different sensors and mechanisms. One thought I’m having is that it’s good to mentally separate the thing that detects the motion (sensor) from the thing that provides the motion, springiness, and damping (mechanism). It sounds like as long as you have a suitable sensor, the mechanism is maybe more important, because that provides the feel of the instrument.

Josh could you describe what a good Touche feels like to you? Is it soft or stiff? Does it move with pure springiness or do you feel some friction/damping? If you quickly lift off of the Touche does the block move back into position smoothly or does it bounce? Haha sorry for all these questions, I just don’t have one for myself to feel.

On a side node, I’d also like to add the natural vibrato where the entire keyboard wiggles left and right like the Ondes. Could you also help describe what the vibrato motion feels like? How far does the keyboard wiggle (in some videos it looks like the motion is tiny, about 1mm)?

Thank you!

You can find more about the Touche here
Also the Touché from Expressive-E comes from a University study (LAM… see here Témoignage membre #3 / Expressive E ou la touche musicale | by Usine IO | Usine IO | Medium) where the goal was to replicate and extend the behaviour and the feeling of the Touche of the Onde Martenot.


@Anckorage , wow what a great doc (even without speaking French still very informative :slight_smile: ) - thanks you are a wealth of interesting knowledge :slight_smile:

what struck me is the ‘bag of carbon’ approach comes from a time where it had to be a complete analog process.
these days, its tempting to say, we can do this with a controller with sufficient travel and a linear response , and then digital map this to any response curve we want.

however, the disadvantage of this approach is it only address response rate, it does not address tactile feedback … e.g. the fact that the bag will feel harder to press as it compresses.

I guess this is why finding the right mechanical surface is still important today in the digital world (to get the ‘best’ results).
and until haptic feedbacks develops much further (which I think is still a way off yet) , this is going to remain the case.

I really should look at where DIY haptics is at the moment, I think this would be a really fun place to do some experimentation.

note: I will say, Apple’s use of haptics in the Magic Trackpad still absolutely blows me away - even today, my brain still cannot believe it doesn’t ‘click’ when you turn it off :slight_smile:


DIY Ultrasonic Haptics…levitating MIDI controllers…now you’re talking. :grinning:

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