[Elecraft] K3: KXV3B in an Older K3

[David and Dianne on Comcast]

Hi Wayne and all at Elecraft.

My K3 circa 2/2008 was originally purchased 
without a KXV3.

I may be interested in the KXV3B for my K3 as the 
K3S FAQ's indicate is possible to do.

But the KXV3B manual now on the download page Rev. 
C dated May 27, 2015 does not mention anything 
about the new 12,10 and 6m preamp being built-in 
or how to activate or use it.

Can the KXV3B be used in an older K3 at this time 
or is a future firmware release needed first?

Or am I misunderstanding something?

Thanks,

73 de N1LQ-Dave