I run the Luxman C-9000u preamp and it is wonderful, probably not 20K wonderful. Found one used and very clean. I was running the Weiss 501 DAC as a DAC obviously and a preamp. Tom at Big Ear suggested that as very talented as the Weiss preamp is, a high quality preamp would probably be more dynamic. He was correct.
The Luxman has great drive and improved sound stage. And it is just plain gorgeous. I know, you cannot hear gorgeous. But then my speakers are in rosewood. And I cannot hear rosewood.