Look at the Audio Advisor website. They carry three or four banana to spade adapters where the spade gets attached to the binding post on the amp or the speaker and the banana on the speaker cable gets inserted into the banana port on the adapter. I think prices range from about 15 to 25 bucks for four.
Bannana to spade adapters
I need to hook up bannana terminated speaker cables to a Classe 301 that only accepts spades. Does anyone know of a high quality bannana to spade adapter? (Ironically, I have spade to bannana adapters, but they won't work -- has to be bannana (on the speaker wire termination) to spade at the amp terminal.