Nothing groundbreaking here, just thought I'd draft a layout of the Phase 90 that facilitates a couple mods.
The first is a switch to kill the dry signal, leaving you with a vibrato sound similar to what you'd get from a univibe. I added a 100nf cap in series with the 150k resistor that gets disconnected by the switch - I had been getting pops whenever I used the bypass switch before, and found that adding the cap there fixed the issue. The second mod is a 50k trimpot instead of the 22k resistor that goes to the script switch. This can be adjusted to give you more or less feedback if desired. Finally, I changed the 47uf electrolytic to 100uf to help filter from the power supply (can't hurt), and I changed the 4.7k resistor in series with the Speed pot to 2.2k to allow faster speeds.
With the exception of a small change I made on the left side of the board (where I fixed problem of the original layout for the phase 90 where a link goes over a wire), this is pretty much verified by me, so it is safe to build. For anyone wanting to take it further, you can do what I did and take the wires for the Speed pot, connect them to a 3PDT footswitch, wire up 2 pots and 2 different coloured LEDs, and have yourself 2 different speed settings that can be toggled by foot.