This week we'll look at another significant development in the world of electronics that would set the stage for all future synthesis. We will look at Lee Deforrest and his journey beginning as far back as 1908.
Lee de Forest built an instrument that used a Triode Tube. This instrument used regenerative feedback which works in much the same way we experience feedback from a mic through a PA system causing an audible pitch. In this case, the tube creates the pitch, and energy is added via a tank circuit to create continuous oscillations through the amplifier. Also, using charged capacitance via turning a knob on a capacitor or putting your hand or finger close to or on a circuit, changes could be made quite easily to the sound as well. A key would trigger the tube to create the notes with one tube per octave. A scale could be created by using a graphite pencil to create resistance paths as well. Thus timbre and pitch could be controlled to create imitative as well as sound "never heard before".
This was way ahead of it's time in terms of gestural control and even predates the Theremin we looked into a few weeks ago. He also put speakers around the room to create the first ever "surround sound" and called his setup music of the lamps. Plans for the Audion Piano were made but seem to never be realized.
This was one of the first synthesizers. Using both audio and radio frequencies, he paved the way for future designs of oscillators, amplifiers, synthesizers and sound projection.