I've managed to get a nice, non-tinny sound

[1j01]

Check out my guitar app here to listen to the results. (Repo)

Originally I was using some oscillators plugged into a tuna effects chain. Naturally it sounded like some oscillators plugged into a guitar amp. It sounded better than plain oscillators but it was mediocre at best.

Then I found this library, and thought, this would probably be better, even if it is a bit tinny.

I took the algorithm from here and put it in a GuitarString instead of a PluckedString class (since I already had a GuitarString class and this library needed updating and I didn't need the flash stuff or anything) and got that working.

Then I plugged it back into the tuna effects chain I had set up. At first it sounded bad because it sort of tapered off in frequency while it was fading out. Then I disabled all but the wah-wah and it started sounding great! Not tinny at all, like magic!

Of course you can hear that there's a wah-wah effect being applied, but there's probably some other simple setup (maybe just a ConvolverNode?) that would similarly smooth out the sound.

I might play around with this more at some point, but for now I'm happy with this.