Use a cable with the end clipped off. I found out on the op1 by accident, as the cable had broken inside. Awful sound quality. Sterling aerial capabilities.
Anyone found ways to boosting the radio reception?
In the Manual is mentioned
“Reception can be improved by connecting an arial or cable
into the output connection.”
Since we only have 1 output, can I then use a stereo splitter and connect one of the out to an antenna for boosting this? [If I dont think that my headphone and audio cable-boost it enough]
Use the shitiest pair of headphones you have with the longest cable possible 
Good headphones with insulated cables don’t work well.
Oh, and I use the European config (even though I’m not in Europe), it seems more precise in the frequency selection.