Afraid not.Thank you for the thorough explanation and content to go with it. Just a question though. You mentioned that I would need to switch the C1 capacitor between 15nF and 1500nF to get the 20 - 20k range. Could I have a fixed capacitance and a variable resistor to accomplish the same thing?
There's already a variable resistor that goes over the practical range limit to adjust the frequency.
You actually need to do three range changes for 15nF, 150nF, and 1500nF.
You'll need a switch, but it could be a CMOS electronic switch, such as a CD4066, if that helps.