The “dualo beta 0”, the first edition of the dualo keyboard instrument

It was in 2007 that the first prototype of an instrument with a dualo keyboard appeared.

Designed and built in the small studio of its inventor Jules Hotrique, this first draft placed the two keyboards side by side, flat. Flor simplicity of design, Jules was largely inspired by the mechanics of the accordion and even used accordion buttons for the keys.

This prototype offered 4 and a half octaves distributed over the two almost completely chromatic keyboards, each with 48 keys, divided into 16 lines of 3 keys, each line corresponding to one note and its accidentals (e.g. Gb, G, G# on the same line).

The recording was done using circuit boards from a kit, compatible with the MIDI standard ( a bit like Arduino cards for connoisseurs). These boards, which required little programming knowledge, were designed and manufactured by a passionate electronics engineer near the Place de la Bastille in Paris. The prototype was therefore a MIDI controller connected to a computer, which served as a synthesiser and sound card.

After a few months of use, it appeared to Jules that the prototype was very large and fragile, and that it was quite an adventure to transport it and to get people to try it out, mainly because of the accordion buttons which became unclipped from their spring mechanisms all the time.

Nevertheless, proof of the interest in the dualo keyboard was now tangible.

The “e-dualo”, the first instrument based on a complete dualo keyboard.

Jules then decided to create another version, more transportable and autonomous.

His friend Bruno Verbrugghe, a computer engineer and specialist in musical gesture, advised him to research the possibility of using force sensors, and not speed sensors as in MIDI piano keyboards. The advantage of the force sensor is that it doesn’t require complex mechanics: a simple key made from mousse enables the force with which the finger hits the key to be transmitted to the sensor.

After many unsuccessful searches, Jules finally found a French company that agreed to see him. His interlocutor explained to him that he had been waiting for such a phone call for ten years, because he had developed his sensors with the idea of making musical instruments, but that he had given up after a big disappointment with a famous musician. Jules then left with a hundred force sensors.

Thus began the construction of the second prototype, still in Jules’ kitchen. The two keyboards were brought back, one opposite the other, vertically, in order to be more compact. Playing became easier, the fingers symmetrically positioned opposite each other to form a complete scale.

Although it doesn’t look obvious in the photo, it was already very easy to see his fingers on the instrument by tilting his head.

For the sake of total mobility and to avoid using a computer, Jules sought to integrate sounds directly into the instrument, then to operate it on battery power. After some searches on audiofanzine.fr later on, a Roland JV1010 expander was purchased second hand, disassembled and then tested whilst plugged into a battery pack. Finally, an XV-2020 expander suffered the same fate and was integrated into this first dualo instrument.

It was also at this time that the question of the integration of a loudspeaker in the instrument arose for the first time. Too heavy and consuming too much battery for a very average sound result compared to the range of possible sounds, this idea was quickly abandoned, in favour of greater modularity.

On the other hand, it was also at this time that a motion sensor was added and connected to the pitch bend of the expander, allowing the pitch of a note to be modulated by leaning forward with the instrument. “Wow!” effect guaranteed and proven!

Completed in June 2008, this first dualo instrument, which Jules called the “e-dualo”, had 5 octaves on two full chromatic keyboards of 64 keys each. Thanks to the integrated Roland XV-2020 sound module, it included 1083 sounds and 17 drum kits. Its autonomy was 8 hours. Jules quickly added two straps to it so that he could play standing up.

Jules used this prototype a lot, because he could take it with him everywhere, playing alone with headphones on the banks of the Seine as well as in jam sessions and concerts with other musicians by plugging into an amp, like an electric guitar or bass.

Jules on the dualo with the group Romolive

Jules on the dualo with the group Arat Kilo

It was thanks to the success of this second prototype, which laid the foundations for the future dualo instruments, that Jules decided to follow up on this crazy idea of creating a new musical instrument….