I have a pair of Bryston 7B STs. I had the same problem in that my MIT spades did not fit in the small opening provided. Either get speaker wire with banana plugs that you can plug into the end of the knob, or get some banana plug adapters to use with your spade ends on your speaker wire. I used Milty locking banana plugs which worked well, but there are others available also. I think that Monster used to make some locking plugs, JA Mitchell used to make some also, but I think that their current versions don't have locking mechanism. Good luck.
