How do these compare with the Eigentakt purifi designs and specs?
Not sure about the Purifi. I’ve never heard them. I have in my theater system the N-core amps which also utilize a linear power supply like the Bryston. Comparing Bryston to Bryston, I find the top end of the BD—325 nearly identical to the 4B3. I found the biggest difference in the low end. In some songs, the 4B3 just hits harder. I don’t know if it’s the interaction with my speakers or what but, all else being equal, in the bass region, the 4B3 has more control over the bass, or more transient capability than the BD-325. I am keeping the BD-325 in my active theater system and the 4B3 will be running the Mini T-10 in our master bedroom system. As a side note, wife absolutely LOVES the Mini-T10. I just got a pair of 7B3 for the family room speakers (RBH 8300/PX) and those things ROCK!!