I've got an amplifier board that has a 2x10 keyed box header with a pitch of 2.54mm (black connector in photo below). It's designed to take the IDC type connector. I want to connect a few channels of my balanced audio source to this box header.
I think the design of the amplifier board is expecting me to make up a daughter board with another 2x10 keyed box header which is connected by a standard ribbon cable. I don't want to make a PCB up for this, and instead would rather take the balanced audio sources and connect it directly to the box header with some crimped connections that work well with a gauge wire that is larger than typically found in the fragile IDC ribbons. I know I can do this using what is commonly referred to as 'dupont' connectors (like the Harwin M20 series), but the ones I can find aren't keyed (they don't have the little notch that stops the cable being inserted the wrong way).
Is there another connector series that is compatible with this box header (including the key for the notch), that I can use to neatly crimp individual wires?