Preamp for a Line Magnetic i518?


I am interested in adding a preamp to my system. Currently using a Line Magnetic 518 integrated 845 SET. I listen mostly to vinyl with a Chinook phono amp and VPI Prime turntable with Lyra Delos. Speakers are PSB Imagine T3. Any thoughts on adding a preamp and suggestions? Partial to tubes but let me know if there is any ss that would possibly be a better match? Budget approx $3500. I appreciate any/all advice....thanks.
ekimg
genjamon: thanks for the response. I had put getting a preamp on hold for a few months but am thinking of it again. I did review some info on the Don Sachs and based on that and your experience with this and others I am seriously thinking of adding a preamp to my LM518 again. I like what you said about the Don Sachs...similar to what I enjoy sonically. Couple questions:  I assume you hook it up into the LM pre in rather than other inputs?  And what interconnects are you using between the pre and LM?

I just rolled in new 845 tubes....Shugang  Replica WE845. Very recent so not fully ready to make a report out but the are sounding very nice out of the box. Also one of my Psvane TII 12ax7 tubes died so I have reinstalled the original tubes for now. Any thoughts on a good upgrade for the 12ax7s?

soundsrealaudio:  also checked out the Ultraverve....looks very interesting too. Couldn't seem to find current cost?  Do you know?

Thanks
ekimg,

I use NOS Tungsol 5751s in my 518IA; I prefer the slightly lower gain of the 5751 vis a vis the 12ax7
facten...thanks for the info. Obviously the 5751 is compatible change for the 12ax7?  What is the benefit for lower gain in your opinion?
I am suprised that the LM518IA will drive the PSB Imagine T3's. I believe it is rated at 22 watts. I am running Shindo Aurieges pre and I tried a Will Vincent Baldwin Amp which I believe is at 25 watts and I felt it was very much underpowered for the PSB's.