I'm writing some software to run auditory experiments. The group I'm working with uses the Babyface Pro. The goal is to send two channels to the headphone stereo output and one channel to one of the XLR outputs on the back. This means that I would like to see, in the software, a RME device that has three channels. The software I'm writing will use portaudio as the backend. However, whenever I query the available devices via the portaudio interface, I see a bunch of different RME devices. They only have 0, 2 or 8 output channels. When I select the 8 output channel device and write a signal to all 8 output channels, these only appear to be sent to AN1.

I do understand that there's an assign button that lets me control what software outputs are routed to the physical outputs on the Babyface. However, no matter what I do I cannot create a three or four channel software-based device. It's pretty important that all channels be in perfect sync (down to the sample) for the experiments.