No no no, IMHO by far the easiest tone generator is a 555 one-it does output an uneven square wave and nothing like a good sine wave, but when the waveform is unimportant and you just need a tone 555's do the job quite well, and you can get them at your local radioshack, or from me, I have about 30 extras lying around.
Here's a good schematic:
The frequency range is a bit high, as you can see, but it can belowered by changing the value of C1. I'd personally go for a .22uf capacitor.
If you wanted a volume control, I'd just put a 100k or so pot to ground right before the output's hot wire (you'd be replacing the speaker with a 1/4" jack on the schematic).
If you really want to do a fuzz in a feedback loop for a tone generator, then by far the easiest would be the easy face:
Youd then basically just want to put a pot wired as a variable resistor from the input's hot connection to the output's hot connection. Normally the pitch is changed via the gain or volume knob. You'd want to put the output coming from after the variable resistor somewhere, and then have a 100k or so pot to ground to control the level.
The problem with this is that it's pretty unpredictable, not very amplitude stable, and not an easy to slap together design because of the trannies.
The 386 is certainly good for making a fuzz like that. Try wiring it like this:
You can ignore the 250uf cap, and you're going to want to put the 10uf cap in there. Replace the speaker with a jack.
You'd then want to put this at the output, right before the jack: