Another option to consider, I had an older plasma cutter without any CNC connections and just made a hole in the quick disconnect plug to splice and solder the needed wires. You would just need a schematic of the pins on the plug. I had all the connections I needed except the ground. This option does not require you to open the case or tap into or track down any internal wiring. The only thing I had to connect in the case was a tap off the ground which was easy to find. I not sure if the connector on the spectrum has room but it if does it might be easier and less invasive.