Electronic Musical Instrument

[bittern]

Hello, I am about to embark on an electronics project, whereby I will make an electronic musical instrument. The principle is to use a 555 IC and a speaker. Of course, variation in the resistance will alter the frequency. However, I would like to be able to play chords; in other words, I want a single speaker to play two different frequencies simultaneously. Is this possible?

The circuit diagram is based on this: http://www.design-technology.info/ks3/y8/page9.htm

Thanks

[Pauldf]

Connecting two resistors simultaneously won't give you the effect you want, it will in essence parallel the selected resistor hence you'd end up with whatever frequency is given by (R1+R2)/(R1*R2).
You need to sort of add the waveforms together, it can be done using op amps etc.

[bittern]

Thank you!

[oram]

Hi Bittern. There is the 74c14 ic that might be best for your purposes. It's easy to use and wire and the internet is full of schematics. To get a good chord you may want to mix each oscillator, a tl074 would be a good bet.

[bittern]

Thanks oram I will look into this.