Doing a search in the Bryston forum: offers:
https://www.audiocircle.com/index.php?topic=121466.msg1278882#msg1278882Basically says:
"Without any changes to a BP-25MC can a MPS-2 replace the MPS-1 using a stock cable from the BP-25MC"
and the answer from Mike Pickett:
"Your BP25 can be powered by an MPS2 without modification, using a XLR6M to DIN cable, provided at no charge when ordered with the MPS2. This won't take advantage of the separate low voltage supply in the MPS2, but should improve performance to a certain degree.
Upgrading the BP25 to a BP26 will allow you to take full advantage of the MPS2.
=====================================================
So I guess you would need to order the XLR6M to DIN from Bryston