Frquency/Sound Creator

[aren55555]

Hi there, I am a high school student, and for a computer engineering project I am looking to build a circuit that can play 5 different notes or frequencies similar to those from a piano. I have looked all over the net, and to my dismay I never found a circuit I was looking for. Basically I want to build a simple circuit first that can play just one frquency, test out the different components to see how they affect the rsulting frequency (ex. if a variable capacitor changes the frquency, i will set it to the right amount to produce the correct frequency) then i will build 4 more with the correct frquencies i am looking for attach push-button switches and play it like a piano (just for reference my frequencies are 174.6Hz,185.0Hz,196.0Hz,233.1Hz, and 261.6Hz. It would be much appreciated if somone could please point me in the right direction. Thanks!!!

 

[The Mad Professor]

You could try a "Theramin" circuit, it's not exactly what you are looking for but it might give you some ideas.

 

[jbeng]

If you want a sine wave output, you might want to try a "Wein Bridge Oscillator".
Here's a link:**broken link removed**
Jeff

 

[freeskier89]

Its actually quite easy to do with a 555 timer, you just vary the resistance of a resistor. Research 555 timers... there is a lot of information out there about them. If you need sine out with that, you can run the square wave through two integrators.

 

[audioguru]

Somebody on one of these forums is also making an electronic piano. Except his has many oscillators so he can play many notes at a time making chords.

"In the good old days" an IC was available (a top octave generator) that accurately made the 12 frequencies in one octave. Now this poor guy has to manually tune each of his oscillators.

 

[em2006]

"In the good old days" an IC was available (a top octave generator) that accurately made the 12 frequencies in one octave. Now this poor guy has to manually tune each of his oscillators.

Not only "in the good old days", but right in our 21st century, this IC is available, if someone does not want to manually tune each of his oscillators.

Anyone who loves electronics and music can have this IC at least from here:
**broken link removed**

 

[audioguru]

FORTY BUCKS! I should have got some back in "the good old days" when they were cheap then sell them for forty bucks (to who?) today.

 

[Nigel Goodwin]

FORTY BUCKS! I should have got some back in "the good old days" when they were cheap then sell them for forty bucks (to who?) today.

Well they won't be modern chips will they, they will be ones back from the 70's when they were made - as such stocks will be limited, and you can charge a premium price for them.

 

[aren55555]

Thnx for the help

Thnx for all the help I, used one of the links all of u posted and found another project somewhat similar (pdf format) http://ece.uprm.edu/~pol/icee04CruzPol.pdf

 

[audioguru]

See? If those 11 year old little kids can make it then you can make it too.