If you are talking about the old 7kd (not the 7k2d) then I don't know anything about those yet, I have several here but they just came in today. But also I am pretty sure the design is not very different at all between the two models. Same operation of the output fets and power supply, just different boards, different configs. Will see... The 2k5D, if it only has 1 output inductor only needs half of the drive circuit in the 7k2d to work.
Check the datasheet on the IR2010. It has only 2 outputs to drive with. If your FETs are divided in 4 groups you need 2 x IR 2010 to drive the whole batch correctly. I believe the only reason that they design class D amps with more than 1 output inductor, which is all that is necessary, is because the size of 1 inductor to be able to handle all of the amps power output would not be very small/compact, would not fit inside, and would likely overheat so they make it drive in 4 or 8 groups and use 2 or 4 output inductors correspondingly to combine down/filter all of the output from those groups/banks. I am not an engineer though, so I am not sure about that, but that's my impression from working on them.
