Thanks for the photos! Given the processing power and amount of Flash and RAM, I'd expect that this hardware has enough bandwidth for a few more firmware revs.
I am happy to see that the analog output section is completely separate from the 32 pin interface, which confirms that Mackie could send whatever output bus they want to the iPad.
As expected, there are pads for adding JTAG headers for both processors (just in case anyone wants to get serious about hacking the unit) Also a few unexpected things: It looks like there is an unpopulated circuit next to the pink version tag. Any idea what that was for? It looks like a power supply circuit, but hard to tell from the photo rez. Also there are 7 diodes that appear to be LEDs (again hard to say for sure from the photo). Some sort of diagnostic info maybe? Did you power the unit up while the board was exposed?
I'm assuming that the CR2032 battery in the bottom left corner is used to back up fader and effects settings in SRAM, so that if there is a power failure during a show, you dont lose the current settings. If you havent already put the unit back together, it might be worthwhile to remove the battery, just to make sure that shows and presets are not being stored in SRAM as well (hopefully those go in the Flash). The CR2032 will probably have to be replaced every few years or so, which is no big deal if its only being used to ride through a power fail - however if one were to lose 5 years worth of shows and presets when the battery dies, that would be a real problem.
As far as the paddleboard goes, at USB data rates, I wouldnt worry too much about RF from those traces. The real problem is noise from the iPad charging circuit when the iPad battery is low and taking full charge current. I'd expect that if you doubled the size of the output cap and paralleled a 0.001uf across it, that would quiet the charging circuit enough to be able to use a longer 30 pin adaptor cable, even when the iPad battery is low.
