How do I connect my speaker cables to this Coda Amp

I need help from all of you Coda owners out there please. 

I just purchased a Code 16 amp. and the speaker terminals on the back are a little unusual. I can't connect the spade ends of my cables to the terminals, they just don't fit. I have Kimber Select speaker cables. They have the larger style spades. When I look down at the terminal I can see that the spade will go down over the gold plated post, but there is a clear plastic sleeve built around the terminal that will not let the spade slide down in around the post. I guess I could buy spade to banana adapters but that seems a little chintzy. I called Coda and left a message but have not heard back yet. They are usually very good. Is there a secret that I don't know about?