Don't sell short your idea of a decent set of mini-to-RCA adapters. Your Cowon can play FLAC and other high rez files so why not use quality cables?
I, myself, have a Fiio E17 and use an aftemarket LOD from my iPod Touch to the E17 for the same reasons mentioned. To avoid the high priced cables you can go to eBay and get a set of Zu Audio Mission cables at auction prices, like I did and never look back, knowing you didn't spend a small fortune.
If it gives you peace of mind, there is a return policy which should give you enough time to compare for yourself.
All the best,
Nonoise (Reviews | Threads | Answers | This Thread)