The simplest possible circuit to generate a sound... (beginner)

[Andrew Schrock]

On Thu, 3 Jun 1999, WahwaH wrote:
>       Lately I got myself very much interested in building my own
>       stuff to synthesize a sound.
>       As I am just a beginner, all the schematics I have seen so far
>       are very complex and I don't think I could build anything like
>       that.
> 
>       For the beginning I would like to ask you:
>       What is the simplest circuit that would generate a sound (any
>       sound - saw, square, sine... doesn't matter)? Could someone
>       please show me schematics of such circuit?

You could try a very basic "theremin" circuit, there are a few floating
around. I shouldn't even call it a thermin, it's far too simple. 

You could also go for an LFO and change the timing capacitor to something
smaller to increase the frequency. Then basically you'll have an
oscillator which you control the frequency of with a potentiometer. 

Toms site at www.mindspring.com/~vco has a lot of simple circuits. Look
around and check it out. You should be able to breadboard any of the
circuits there. 

>       I mean it should say "ZZZZZZZ" when I turn it on, and also
>       hopefully there would be a potentiometer to control it's pitch...
> 
>       If I build it correctly, later I would step into filters.

Actually, filters can be fairly complex, depending on what you're working
on. 

>       Please understand me, right now it is terribly hard for me to
>       look at these complex schematics for generating beautiful
>       sounds. I need something simple to generate a beep or zzzz.
> 
>       Also, would this be possible with a 9V power source? (If not -
>       that's ok, I'm just asking). ;-)

Sure! 

FYI The three things I think you need to start synth-DIY are: <drum roll> 

1) An antistatic wrist strap to keep you from zapping parts. 
2) A good soldering iron. (I found a meat&potatos weller for $20 at a flea
market) 
3) A simple DMM, radio shack will do. 

Optional: An oscilloscope and a well-stocked parts drawer. 

Andrew

-| Andrew Schrock | aschrock at cs.brandeis.edu |-