which preamp match best with Krell Evo 402 ?

I concur on the Evo222. I have one with the Evo600s and it's great, particularly in cast mode.

I see either 202 or 222 will be a nice match acording to suggetions. However, Audio research Ref 3 would be another strong candidate?

Forget the pre-amp, go direct in with a DCS Elgar DAC.
Audio nirvana!

With mediocre ones probably yes, you will be better off going direct from an Elgar Plus to amp. However, given good/excellent ones, no way, Imo running a pre-amp is still the way to go--much better.

Actualy I bought ARC ReF 3 . Thanks for inputs!