The AV 5103 is simply the best by far of these three if you are going to use it as a two-channel preamp. As for home theater, I can't comment. It is possible that the Krell and the EAD may have some newer video processing features than the AV 5103, which went out of production in 2003. Sonically, I dont think there is going to be much of a comparison.
But mind you, I dont like the Krell gear Ive heard at all. If you do, our tastes are very different and so my advice might not be that useful to you.
But mind you, I dont like the Krell gear Ive heard at all. If you do, our tastes are very different and so my advice might not be that useful to you.