Hi,
I am using Cantabile 3.0 with my electric violin. Similar to a guitar, I have a single mono cable off of the instrument which goes into an external audio card, and the sound card sends the mono signal to my Surface Pro 4 via a USB cable.
Is there a way simply using routing or possibly setup options to route the mono signal into a stereo signal? [Something outside of a vst plugin]
You create a mono input port for your violin and assign the audio interface channel to it that your violin is connected to.
As soon as you connect a mono port to a stereo input, e.g. for a reverb, your input should automatically be connected to both channels of the plugin. Instant stereo!