OK, thanks for the replies.
Yes, I bought the pre in a package from Chris. I don't have a BB. The pre-amp size is not really a concern for me, so I'm fine carrying around the CA-9100 for whatever purpose it needs to serve.
As for the battery, the 9100 takes a 9V. I had an alkaline in there that only had a couple hours use on it. I just metered it, and it's holding steady at 8.7V.
Any other suggestions?