sound generator

[sniffer]

I am looking for sound generator from 300 Hz frequency up to 1.5 KHz, with adjustable volume. Is there such a thing in the electronic market? I also want to know the frequency it produces as I turn the knob.

If I want to make the circuit myself, where do I get the circuit plan?

[Cliff_J]

So you're looking for a signal generator that makes pure sine waves? As far as volume is concerned, you could always use a pre-amp to feed your amplifier that feeds the speakers (or right from the pre-amp to headphones). There are commerical ones but may be slightly difficult to locate.

For circuits it is something you can find via google pretty easily, here's one with a wien-bridge oscillator:
http://sound.westhost.com/project22.htm

And here's a application sheet from national:
http://www.national.com/ms/LB/LB-16.pdf

[sniffer]

Thanks a lot for your advice, Cliff.
Now I have been reading the website you quoted, and I found it quite comprehensive.