[Elecraft] low pass filter from kaf2 questions

[Gary Lee]

Received a message from Lyle Johnson recently regarding increase in hiss 
after installing kdsp2.

The Gist was that there is a permanent low pass filter in the kaf2 which is 
not present in the kdsp2.

1.  Has anyone added this back to their k2?

2.  If so, what components do I need for this?

3.  Would someone be willing to do this for me?

Maybe being blind I notice a little more, but I would really like to have 
the sound of the old k2 back.

Thanks for any help.

73