Yikes, this is a tough PCB. It's 99% there, but that last 1% is recalcitrant. I've been trying to decide how to handle the 2 delay chips. At the outset, I only thought I'd use them in series for double time. But it really does seem a shame to have 2 delay chips and not allow for crazy parallel delays.
Plus, imagine how awesome it would be to have 2 delays in parallel using the PTAP: since it allows you to do different divisions of the tapped tempo, you could set the delays to be perfectly in sync in a 4-to-3 time relationship, without having to tweak the delays really carefully. Just tap in your time and out comes a perfectly synced polyrhythmic delay!
So the only problem is doing the PCB in such a way that you can do those wacky things, but figuring out how to build it isn't a chore. I really like the majority of the build to be obvious just by looking at the board, without having to dig through a PDF, and I've mostly achieved that. But this parallel/series switching is going to be really hard to pull off cleanly.
Two separate delay lines sound cool. I remember some algorithms in my old Lexicon Vortex, you can do thing like series or parallel arrangements with some cross feedback lines...
Now that thing is one of my favorite effects units ever. I think it was the "Bleen" preset, which was like a multi-tap delay with a ring modulator in the feedback loop... that, plus an Ebow was "my sound" for awhile. I need to code up a workalike in the FV-1 chip now that I don't have my Vortex anymore.