[sdiy] Ondes Martenot Schematics

[Mike Beauchamp]

I'm really happy to share this with the synth-diy community, as these 
schematics are something I have been searching the internet for over the 
last 14 years.

http://ondes.net/

I have been collecting all of the information I can find on the Ondes 
Martenot for quite some time. Although there were rumours of people 
having copies and one being briefly shown in the film "Wavemakers" 
(https://www.nfb.ca/film/wavemakers/), actual schematics seemed totally 
unobtainable.

Several years ago, I reached out to a man named Jean Landry who had been 
a repair technician and also worked and taught at the Conservatoire de 
musique de Montréal, which as far as I know is the only place that 
teaches the Ondes Martenot in North America. During a visit to his 
modest repair atelier, he pulled out several original schematics from 
his filing cabinet and very kindly offered to scan them for me.

Once I saw the schematics, of course I started simulating and 
breadboarding the oscillator core, waveshapers and mixing circuitry. 
After making some improvements to the stability of the oscillator, I 
designed the Therevox Ondes VCO for eurorack as a side project during 
the development of the ET-5.

Jean continued to scan and organize more documents he had related to the 
Martenot, including original operating manuals, technical bulletins and 
everything else he could find. Jean and I are both former guitar amp 
repair techs, and we talked about how vintage Fender amplifiers will be 
around forever because their schematics were always top-notch and 
available. Jean wanted his Ondes Martenot information to be available on 
the internet so it might help others repair the few Ondes Martenot 
instruments that are left in the world. He did most of the work, I'm 
just a guy that knows a bit of html and happy to finally put this stuff 
online.

Mike