Hey there hopefully someone can help me out. I’m wanting to create new input and output buses in cubase 5 because I recently got a new recording interface (old one died). I was wondering if deleting the buses for my old interface and creating new input and output buses for my new interface will mess up existing projects/recordings I have saved? Will I still be able to work with my existing projects like normal after deleting the old buses and creating the new buses? Thanks.
Well… your old interface died. So you have no choice except to create the I/O buses for your new interface. Most likely from a new/different driver for your new interface. Existing projects that have tracks routed to different buses than what is available on your new interface will need to have those track input and output buses changed to the new ones. Especially the input buses, if they are different from your old interface and you intend to record more stuff for your existing projects. The main stereo out will probably be fine because the Cubase stereo out track defaults to whatever is assigned as the main stereo out bus. But the existing projects should work fine after you reassign the I/Os. It’s just going to be the PIA factor for revising the buses.
Have fun 
Regards 
You´d better not delete the busses, but simply reconnect the the device ports for the existing busses!