@shkong78 Sorry to leave you hanging. My weekend didn't go as planned, so I have not yet had an opportunity to follow through on running the 3400 as a preamp for the LM 508, but I will get to it sometime this week.
In the meantime, I am really enjoying the 3400 as is. I was unable to read the review--is there a way to translate it to English? But it sounds pretty much in line with where I am--the ONLY area where the 3400 doesn't quite match the 508 is in the midrange, but I do look forward to an A/B comparison to see just what the gap may be. There will be gaps in the 3400's favor as well.
Also, as a previous owner of a Devialet D200, I can say without any doubt that the 3400 is far, far better in my system and to my ears. I thought the Devialet sounded clean and clear, but in the long run, it was just not as musically engaging as I wanted it to be. No such issue with the 3400, which is keeping me nights listening and smiling.