Best Preamp for Hovland Sapphire Amp and Quads

I have a Hovland Sapphire EL34 tube amp and Quad ESL 63 speakers. Presently, my source is a Pass Labs DAC1, which has a SS preamp built in. The sound is excellent to my ears, but I have wondered about adding a tube preamp to the system, to take it to another level. I also would like to have a remote control for the volume. Don't need phono stage at this point in time. I know that Hovland makes a couple of good preamps, but they are so darn expensive.....thoughts and suggestions for cheaper options, preferably under $2,000 used, would be appreciated. Conrad Johnson? Sonic Frontiers?Thx.