Pitch-reference oscillator Pitch-control oscillator Mixer Volume-control oscillator Volume-resonant circuit and voltage-controlled amplifier Audio amplifier 12-volt power supply
Read an electronic schematic Solder electronics Wire a potentiometer Wire a circuit If you want to put a theremin together, kits are available at a variety of different price ranges, some of them relatively easy to put together and some more complex. It’s somewhat easier than starting from scratch and getting all the boards and circuits you’ll need individually. Unless you’re an experienced maker of circuits, it’ll be difficult, though not impossible, to make your own theremin without a kit. [2] X Research source
The top should be hinged so you can install the components and make adjustments when necessary. Kits are available for this purpose, which can be a good idea to get the basic housing shape, even if you still want to customize the circuitry.
While it may seem like it’s more important to wire the circuits first, it’s much easier to get the housing in place before you start worrying about the circuitry, to make sure that everything is spaced accurately and comfortably to play. Just as you’d build the guitar’s body before wiring the pickups, you want to start with the housing. You’re making an instrument, not a radio.
The pitch-reference oscillator should work around 172kHz, used in conjunction with a 10k potentiometer. The signal this oscillator creates should be fed into the mixer with screened cable. The pitch-variable oscillator should also work around 172khz, and will be affected by the stray capacitance of the reference unit. Potentiometers need to be wired into the circuit to make the relationship of your hand movement to the change in pitch more linear. Without them, the instrument’s pitch be almost impossible to control, changing wildly with only a microscopic movement of the hand. [4] X Research source
Send the output of this variable oscillator into a volume resonant circuit. The output will be a DC voltage that varies according to the output of the variable oscillator. [5] X Research source Tuned correctly, the oscillator frequency will match the tuning of the volume-resonant circuit as the operator’s hand approaches the antenna, causing the signal to cut off gradually. In other words, the closer the hand to the antenna, the quieter the sound.
The output actually contains two distinct frequencies, which require the need of a low pass filter, that is two 0. 0047uF capacitors and a 1k resistor, used to extract the output and boost it into a listenable range.
Use extreme caution if you’re not an experienced electrician. There’s a fairly serious amount of voltage going through these circuits, and fire or injury can result from mistakes. Brush up on the skills outlined at the beginning of this article before trying to wire these circuits and apply them to power.
In order to test and tune the modules, hook your theremin into the input jacks on an oscilloscope and you’ll be able to see the sound waves you’re creating as you manipulate the theremin. Adjust the modules accordingly, if the sound waves are off.
