I doubt Krell would still have the parts. An MDA model uses a different input board - it is not a bridged amp. I love my KSA-250s. If your amp has not been recapped I would recommend you do so to breathe new life into it. An amp of equivalent quality today would cost north of $15K.
Does Krell still convert KSA 250 into MDA monoblocks
I have a KSA 250, and would like to purchase another one if Krell, or someone is still able to convert them to monoblocks... any help would be appreciated. Maybe a private shop would do it if Krell doesn't anymore...