Cubase is not working with my USB MIc.
BUT WAIT! Hear me out.
I have a Mac Mini. The default input is the USB Mic (a Blue Snowball)
When I use “Built in audio” as the ASIO driver, nothing records, but it plays perfectly fine through my speakers.
When I use “Blue Snowball” as the ASIO driver, it records, but nothing plays.
I’ve tried going to VST connections and making a bus for the mic, but it does not show up as an input. All there is is “Built In Audio”, which does nothing.
I’ve tried setting up “Built In Audio” to have “Blue Snowball” as the input, but it’s not detecting it.
If this has no viable answer, then I’m taking this straight to Steinberg.
That’s because a USB mic is presenting itself to the system as an audio device having 1 input and 0 outputs. Cubase wants to talk to only one audio device at a time.
Fortunately on the Mac, there’s a fairly simple solution.
You need to open Audio MIDI Setup.app in your system’s Applications/Utilities folder and create an aggregate device (a “virtual” device) that includes both the Built in audio output and your USB mic.
I won’t post instructions on how to do it, they’re easy to Google. 
Then open Cubase’s Device Setup window and use the aggregate audio as your “ASIO Driver”