Does anyone know if it’s possible to connect the QC directly to the USB (C) input on a mixer (a Boss Gigcaster 5).
The Gigcaster can take a direct USBC input so for example I can plug my iPhone directly in to the USBC port on the Gigcaster and it will see my phone as an input source. I was hoping I’d be able to do the same with the QC, so the mixer sees that as an input source, but so far no luck.
Any ideas anyone? 
I’ve never used a Gigcaster 5, but I don’t think that it will work.
In USB connections there is always a host and one or more peripherals. The host is in most cases your computer or smartphone, using an audio interface (like the QC) as a peripheral. So in your specific example the iPhone would act as a host, using the QC as an audio interface and sending and receiving audio.
Nothing I can find online about the Gigcaster 5 suggests that it can operate in host mode. I also did a quick web search for such devices and didn’t find anything similar.
Thanks for the detailed reply, shame as it would be a really useful way of ‘freeing up’ one of the inputs on the mixer by allowing me to use the dedicated USB channel on the Gigcaster…
Yep I’ve looked for something similar to see if you could somehow hook up a Boss RC-600 Loop Station and the QC without analog cables.
I guess it’s too complicated to implement in a standalone device.
With XLR and TS/TRS you have 1:1 connections, while your USB device can have many channels.
You can use a computer as a digital mixer. A DAW like Reaper works great. See Using a DAW for band rehearsal.