What bose System
Which Bose system are you using? I used to have A lifestyle 28. If this is the one you are using, or if yours is similar. If I remember correctly you can buy an adapter for the connector. If your facing the same thing I faced, limited inputs on the Bose. Although it wouldn't be the best fix you can buy any receiver with an optical out and run it to the optical input of the Bose which, even with a lowend receiver, will give you a significant # of inputs + you will still have the benefits of the EQing features of the Bose receiver, which are the best option IMO for the Bose Cube array.