Building Your Own Electronic Organ Circuit

For as long as we can remember, music has been a huge part of our lives.

And guess what? It keeps changing along with all the new technology we invent.

Electronic instruments especially electronic organs, are a great example of this.

They have totally transformed the way we make and listen to music.

The Technology Behind Electronic Organs

Even though fancy organs are expensive and tricky to build, you can make a simple one yourself with a basic circuit.

This circuit is easier to use than others because it does not require a complicated setup.

• One part tone generator makes the basic musical tones.
• Another part vibrato unit can add a little shake to the sound, making it more interesting optional.
• You touch a probe to choose different notes.
• The sound changes depending on a special chain of parts.
• The whole thing uses very little power, so you can run it with a regular battery.

Advantages:

• Simplified circuit for easy construction.
• Low current consumption, suitable for battery power.

Disadvantages:

• Limited note character and pleasantness.

Construction and Battery Consumption

Parts List:

Construction can take any form, but it is essential to note that the probe cannot be metal.

Various probes can be tried until one that instantly makes a nice clean note is found.

The circuit consumes a low amount of current and can be powered by a PP3 battery.

The tone generator comprises a unijunction transistor type 2N2646, C5, R5, VR1 and the tone resistors. The emitter of the unijunction goes to a probe which can select the correct notes.

The frequency of the note depends on the total resistance in that chain, and VR1 is preset that alters the whole range.

The output is taken from the oscillator via C6 to the volume control, which should be connected to an external amplifier.

The circuit will produce the correct notes but may lack character and pleasantness.

The vibrato unit works at a frequency that will lie in the range of 10Hz to 30Hz and raises and lowers the output level very slightly at this frequency.

This stage can be built separately and mixed with the note to add character.

It is strongly recommended to fit this stage.

The oscillator is a phase shift type, and the output is taken from the collector via C4 to feed directly to the emitter of the unijunction.

The low frequency note is not heard when the probe is not selecting a note.

Phase shift oscillators can sometimes be troublesome, but a slight change in the value of R3 usually cures the problem.

Formula:

The frequency of the note fnote depends on the total resistance Rtotal in the chain, as given in the following formula.

f_note = 1 / (2 * π * R_total * C5)

where,

• Fnote: This is the frequency at which the circuit produces a musical note.
• The frequency of oscillation or tone generated in electronic circuits, especially oscillators and tone generators, is important and is frequently dictated by the values of the resistors and capacitors in the circuit.
• Rtotal: This is a representation of the circuits overall resistance, which influences frequency.
• This might really be a mix of potentiometers (variable resistors) and fixed resistors.
• C5: This represents the circuits connected capacitance value (in farads).
• The time and frequency properties of oscillators and tone generators are largely determined by their capacitors.
• pi: about 3.14159 is represented by the symbol π and is utilized in computations pertaining to circles and periodic functions.

Note:

The formula shows how to determine the frequency of a musical note produced by an electrical circuit by using the circuits total resistance and capacitance values.

It is necessary for creating and modifying circuits that generate particular tones or frequencies in music.

Modifications to C5 and Rtotal enable for tuning to alternate notes or frequencies as required.

Conclusion:

Building your own electronic organ is not only a satisfying endeavor but also an educational one.

It provide a fantastic opportunity to look into the basics of music theory and understand the inner workings of electronic instruments.

With modern technology at your disposal, constructing an electronic organ has never been more accessible.

We hope this article has not only inspired you to explore the captivating world of electronic organs but has also equipped you with valuable insights into their technology and construction.

Now, it is your turn to unleash your creativity and start building your very own electronic organ ready to produce beautiful music in your unique way.

References:

Electric organ

Electric Organs and Their Control