Here is the setup. You will need split you audio output with stereo to dual mono cable. On one channel you connect the fader, and on another, you connect a speaker. Then you add a sine wave oscillator and a scale changer to fit the value frome fader to the frequency of the sine wave oscillator in your software. Now, you can finely control the sine wave oscilator in 16-bit resolution.
Here is a MaxMSP patch.