The LFO section is *very* sensitive to both voltage and current, so if your board doesn't fire up right away (which happened with my second build too), you should consider doing a little daughterboard with 9V regulator, 8V2 zener and a 10-50 trimmer to get the LFO going. That being said - this is not a project for beginners.
Mr. Hollis has been known for his modulation circuits. This one seemed like an interesting build so i drew it up. Once again. I'm more or less out of sources for the demos and so on. But i have a hunch that this may be 1:1 with two knob version of Copilot FX Android... Anyway. The circuit does tremolo from mild to wild and flick of a switch turns it into super mean ring modulator - with lots of good stuff on the sweep. Or so i'm told.