This is a one-string instrument. It is played by stopping the string in the middle area to create two string segments that can be sounded separately or together.
The vina bambina was originally designed as a long steel string to be bowed for harmonics. At some point I put a bridge in the middle of the string and found that I could produce a note from each end of the string. The first bambina used a 4' PVC pipe about 7 feet long to support the piano wire string. I used a movable bridge to divide the string.
I made the wooden vina bambina, illustrated, with a long finger-board to do away with the movable bridge.
The wildwave consists of two sine wave signals processed through a mechanical/electric resonator. It is played by controlling two audio oscillators with their signals mixed equally, amplified, and sent to a transducer, which consists of a drive post (plastic foam or cork) attached to the drive coil of a speaker. This speaker-head is suspended over a balanced metal plate so the post delivers vibration to the plate, but the linkage is not fixed, so it is free to bounce on the plate or drive it. The resulting vibration of the plate is picked up with a piezo contact mic and sent to an amplifier and speaker.
Diagram of the Wildwave Instrument.
Click to enlarge.
While teaching at a high school, I obtained a hollow iron ball about 18" in diameter that was discarded by the math department. It occurred to me that it could act like a bell if I cut slots in it, which I did with a nibbling tool. I didn't know what shapes would work best, so the whole project was an experiment. It ended up with multiple tones and a good sound.
The guitoura is an old acoustic guitar strung with four strings and a flat bridge so it acts like a tamboura. I carved the flat bridge from a dog bone. With threads under the strings it is somewhat effective.
Flute with Ring Modulator
I had obtained a microphone for the flute I have played virtually all my life. My idea was to incorporate a ring modulator with the flute sound using a Freeze Pedal and a two-input ring modulator. The signal from the flute would be split between the Freeze Pedal and one input of the ring modulator. The output of the Freeze Pedal would go to the second input of the ring modulator. At any moment the flute player could hit the Freeze Pedal to sustain the note being played. Everything played then would be modulated against that tone until hitting the Freeze Pedal again.
Ring modulators are commonly designed with a single input that is modulated against an internal frequency generator. My difficuty was that I could not find a two-input ring modulator. I mentioned this one day to Peter Blasser, a remarkable electronic instrument designer and builder. He forthwith produced a circuit design for such a ring modulator. Under his supervision I built the circuit and he helped to de-bug it. The result opened a new world of flute playing for me.