*Errors in the schematic (coupling caps at 0.068µ and not 0.68µ) have now been fixed on the layout...
As requested. Paul Nelson's Orange Graphic MKII stomp box adaptation. I knew this one will get huge the minute i saw the schematic, but it turned out a lot more compact in the end. Even got it nice and relatively symmetric. The FAC switch is a 2 pole 6 position rotary. If you're not familiar with how to wire those, check out Mark's layout for Rangemaster with switchable input caps to get a hold of it. 2N5457 and J201 were suggested for transistors, but you could try out any JFETs you like. Trimmers are used to set the the Drain voltages for ~4.5V.
I've tweaked the FAC cap values for not chaining all the caps after each other, so that part is not 1:1 with the schematic, but the values should be close enough.
With a rotary switch and 5 pots, this won't be a simple task for fitting it in 1590B, but i think it may just barely be doable :P