Serious Passive Preamp question


I have a Audio Research LS7 Line stage preamp and someone wants to trade me my AR LS7 for a serious passive preamp
Is anyone familiar with this company ?... I was told it retails for $2200.
 My  Amps are Class D wyred 4 sound mono blocks.
Opinions please.
rocky1313
Some months back I went passive, and found I was fortunate that my gear ( sources and amp ) were very passive capable. I had a tube pre and a ss pre, both of very high standards and recognized in the audio community for being excellent ( which I will not name ). I will tell you that in my situation, I can never go back to an active pre ( in this particular system. What I am hearing from my sources is less colored, more detailed, and truer to the recordings. I am getting plenty of dynamics ( a very important characteristic to my listening ), and greater PRaT.  Enjoy ! MrD. 
mrdecibel
Some months back I went passive, and found I was fortunate that my gear ( sources and amp ) were very passive capable. I had a tube pre and a ss pre, both of very high standards and recognized in the audio community for being excellent ( which I will not name ) ...
If you won't identify the equipment you've used, the value of your observations are greatly diminished. The reader has no context from which to evaluate your opinion. I've never understood those who post in a public forum, and then play "I've Got a Secret" with the details. What's the point?
While I suspect that in your system’s case an active pre is a better fit, the answer seems obvious to me: try it first! Why not swap for a few days and see what you think? VERY happy passive user here (high power tube monos, very high gain tube phono stage)
I'd never owned a passive preamp until the Schiit Freya came along...the passive option is interesting, but the tube stage has the gain my single ended amp needs. The output switching feature in this preamp seems most useful (to me anyway) as a way to see what the tubes are doing...