You need the either the audio 8 or audio 10 if you want to connect four inputs. the difference between them is the audio 2 has 4 mono outputs for headphones and master or channel 1 & 2. The audio 4 and above have inputs and outputs… To run timecode you need 1 stereo input (2 mono) per device.
The number in the name corresponds to how many mono ins and outs the soundcard has. eg the audio 10 has 10 mono ins and 10 mono outs, it is suitable for running 5 timecodes… They all sound the same though in theory the audio 4 should be the loudest as it doesn’t need to share the power from the usb between all the outputs, unless you connect the ac adapter.
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