8 Note Electronic Organ (how a "practice" kit can turn into a real project)
8 Note Electronic Organ (how a "practice" kit can turn into a real project)

8 Note Electronic Organ (how a "practice" kit can turn into a real project)

I turn NE555 based soldering practice kits from Aliexpress into gifts for children.

Delta Prime

Jul 29, 2020
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A snippet:
One circuit arrangement includes means for combining the fundamental frequency and the second and fourth harmonics in a predetermined time relation to produce the zero, attack, peak, and decay characteristics of a piano voice as actually produced by a piano string. Amplitude limiting means are coupled to the circuit for controlling the amplitude of the harmonics in response to predetermined values so that mixing of the fundamental frequency and the second and fourth harmonics along predetermined points of the piano voice characteristics curve will more accurately reproduce electronically the sounds of a piano. Another circuit arrangement provides means for rapid recovery of the piano circuit so that the keys can be actuated in rapid succession.
US3935783-drawings-page-3.png

https://patents.google.com/patent/US3935783A/en
 

Sidecar Bob

Dec 19, 2021
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That is interesting and I've heard electronic pianos that sound like the real thing but the ones I built are just toys.
 

bertus

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Nov 8, 2019
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Hello,

The following book shows you circuits for music syntesizers.
It is one of the books from this page:

Bertus
 

Attachments

  • Babani-BP185-Electronic-Synthesizer-Construction.pdf
    1.8 MB · Views: 1

Delta Prime

Jul 29, 2020
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pianos that sound like the real thing but the ones I built are just toys
Better than any toy I have seen on Amazon, outstanding! :)
DC power supply inputs should be well-isolated (as fare as possible away) from the audio output(your speaker).
This is done to minimize noise being introduced into your circuit.
The construction of your project boxes is innovative and imaginative, I like it…
P.S. I believe I am witnessing the very beginning of establishing a family heirloom.
 
Last edited:

Sidecar Bob

Dec 19, 2021
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I wasn't too concerned about noise. Anyway, as you can see the power and speaker connections were only about a cm apart on the board so locating them farther apart on the box would have meant longer wires, which would probably contribute to more noise anyway.
PC board.jpg

Bertus: That is neat but as I said, the ones I made are just toys.
 
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