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
As I have said before, a passive preamp can be a tool, but it really depends on your source/DAC and your amplifier.  If you have a DAC that is very fast and solid-state sounding, I think a passive is not really the right tool as you need an active preamp in the middle to help smooth and shape those hard-edged waveforms.   If you have a full Class A or tube DAC/source, then a passive could work well.
I will not name the units, because I know and respect the manufacturers, and will not harm sales by them in any way. My justification and value of my opinions to any of you is unimportant to me. I am just stating the facts of what I am hearing. Enjoy ! MrD.
My Luminous Audio Axiom II, with Walker Mods, single ended, 3 in, 2 out, with remote, is wonderful. Enjoy ! MrD.