KAV 250a input / outputs

I have a KAV 205a that has balanced input and outputs. I noticed some units for sale that only have balanced inputs only. Anyone know why?
Ok, I'll guess. These components are of truly balanced design and the makers want you to use them that way only with no excption that would compromise sound.

I think there are two version of KAV 250. The earlier version is KAV 250 than KAV 250a. The 250a is the latest version and has both. I might be wrong. I have the 250a version.
I think I figured out. The bridging channel switch on my unit is on the back. Ealier models, you had to open the cover to access bridge switch. My unit has input and output ballence and older models have only inputs.