Preamp for Quad 989 and Quicksilver v4

I'm anxious to hear recommendation on a tube preamp for my Quads and Quickies. I'm currently using a YBA Passion pre which sound good, but looking for a warmer tube like sound. My budget would be 1500-2500 new or used. Down the road I may use this set up in my Home Theater so a pass through is important along with a remote.
Please share your thoughts.