Adding tone control to Ruby

[bassmannate]

I'm going to build a Ruby here soon but I'd like to add a tone control to it. I'm using the Noisy Cricket circuit as a guide but I'm not sure of all the parts. The tone pot has a cap to ground which obviously will pass high frequencies to ground when you reduce the resistance to it. What is the other 100nf right after the volume control and right before pin 2 on the JRC386? Is that also part of the tone circuit? The Ruby does not have this capacitor.

http://www.beavisaudio.com/projects/NoisyCricket/
http://www.runoffgroove.com/ruby.html

[emstin1]

I think that's just a normal input cap.