I got the order of four boards from ExpressPCB.com and soldered it together and it works! The only error I made in the design was that the holes for the screw terminal header are not big enough. So, I had to solder wires there. It is not a problem when the board is used in an enclosure since the terminals or jacks will be on the outside of the enclosure. The wires are actually handy when using the sequencer to control a breadboarded circuit. I already updated the PCB layout with bigger holes for the next round of boards I order. I also moved the power switch to the top of the board because it is more ergonomic. Now I will solder up some more boards so I can assemble the enclosures I have ready and waiting.
Pictures and video:
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