Loophole with Modulation.
Sounds really great. Definitely not for precision looping. But perfect if for a looser context.
I ditched the master volume. It's now a trimpot inside.
I also used the 2560P chip for more loop time. You have to ground to extra pins with this chip.
This is not my cleanest build inside, since I did a lot of wiring outside the enclosure, as I was not sure which controls I would ultimately use.