on my cdp-cx450, connected to the cdp-cx230, I use a smaller mono cable that is no-where near as large as a 1/4" plug (like one used on an electric guitar). I used a much smaller plug that is the size of the headphone jack on an ipod. It was the only one that woudl fit. Maybe I am misunderstanding the above posts, or maybe the specs have changed - but I thought the mini-P2 plug was quite small.