I would like to record some audio files from radio in Cubase7.5
How to manage this with an external soundcard (Roland octcapture). 
Thanks for your suggestions
Your Interface has a nice feature, something I look for.
QUAD-CAPTURE has a handy loopback recording feature that lets you capture its main stereo audio output digitally in your recording software without having to connect external cables.
So whatever app makes radio runs it through your interface and it loops it back where you can record it.
I use this sometimes when bouncing or mixdowns don’t sound like they should, record the actual sound!
Check out Audacity. Free audio editor, but it allows for loop back recording from your internal sound card.
Goldwave is another useful tool for capturing from the internet.
Any program that can record can record loopback if your interface has one.
I don’t know about software that will record loopback if your interface doesn’t have one.
But you can make your own loopback, just plug and output pair into an input pair.
Just don’t monitor the input or you get feedback.