I have gone back and forth on this 3 times today in my mind - and figured I will at least throw it out for other comments. Let's say you have a WB68 and 6 connections for 2 HR20 and 2 H20 (actually, this isn't important....but for example). Could you place 4 BBCs on the INPUT of the WB68 between the WB68 and the AT/9/AU9 and thus eliminate the need for them on each individual feed to the H20/HR20 series? Everytime I think I have decided in my mind, I think of another reason to change my mind about 30 minutes later. It would probably be easier to try it, but I only have 3 BBCs at the moment.