I've built a dozen of them. There is nothing special of note, and it is a pretty easy and forgiving build. Just lots of parts. It's just 2 Phasor II's on one board. I've built hundreds of Phasor II's in my life and I could populate them from memory at this point. No need to match the LDRs, and the tayda ones work just fine. It is not a finicky circuit, and uses all cheap and available parts. I use all tayda on these. I leave the trimpots at noon too. I've yet to build one that had any noticeable need to adjust. The Ldrs can lay flat on the pcb like flower petals or standing and facing. I lay mine flat. With the duo phase, light shields should be used to counter crosstalk with the optical phasers. I use 24/40 rubber septa on mine as they stretch a bit and fit perfectly. If you don't use the SCPA 1044 it will whine.