Based closely on the Harmonic Percolator, but with some DEFX twists. First off, we've made the footprints bigger, which allows for use of older, or NOS type components, for extra mojo. Yeah baby! Second, we've tweak some of the capacitor values to make it more friendly to either humbuckers or single coils. This also helps cut down on some of the fizz as well. Lastly, while you can use the typical PNP germanium / NPN silicon setup that is common, we also recommend that you try an NPN germanium in the Q2 slot. The all Russian combo of 1T308B / GT404b, along with D18 diodes, really works well. Our build document will outline what we've used in our build, along with gains, leakages, and voltages. You might just like it Mikey!