The Countdown phaser is a reproduction of the A/DA Final Phase™ circuit, vintage 1979, somewhat different from the reissue. It has been designed for true bypass, and uses a charge pump/regulator setup for 15V operation using a standard 9V power supply. 🙂
Has a built in overdrive operated by a separate footswitch.
Expert level build, due to the size of the board and volume of components.
Note: There are lots of different widths of DC/IN/OUT jacks. I tried to make the drilling template where the widest of everything would fit, but it might be pretty tight up there the way I have it. If your jacks are skinnier you could move them a bit closer together and have some more clearance from the pcb sides on the right & left. In other words, I might recommend eyeballing those top mount holes for your own i/o/dc jacks before deciding exactly where to drill.