Here is an intriguing idea: what if the two touchscreen displays were mounted on a folding panel? An horizontal hinge could be located just below the 8 knobs, alowing the screens and the kobs to be raised at an angle. A simple locking mechanism would be used to keep the display panel locked during transport, while another one would keep it raised and sturdy during use.
This arrangement would have two main benefits: first, it would improve readability of the screens; second, because the backplane holding our 4 Parallella boards will be attached directly to the back of the screens, it would dramatically improve heat dissipation when the display panel is raised. This second benefit is really what sold me on the idea, because the boards can be hot, especially if we upgrade to the 64-core version down the road.
Here is an updated design, adding 12 mm in length and 11 mm in width. Final tally: 351 mm × 268 mm. And with the extra space, we added one more column of switches and some space around the transport controls. The new column allows us to add one switch per stereo channel (labeled A through H), as well as Sel, Mix, Seq, and Syn switches. Last but not least, it allows us to have a much nicer layout for the arrow switches.
As far as the physical UI is concerned, I think we’re done.