What Audio Research preamp would be an upgrade to my LS2B

I moved from an Audio Research LS2B to an LS25 mk2 and the difference was huge. I have now moved to a Ref 5se and again the difference is huge.

 The LS25 mk2 is really a  nice preamp, Very detailed with a large 3 dimensional sound stage. It would be my suggestion unless you can afford a Ref 2 nk2 or Ref 3.

 The LS25 needs to be a mk2. I compared the mk1 and mk2 and the mk2 is much better. The LS25  mk2 and Ref 2 mk2 were the first ARC preamps to use the 6H30 tube. After having my LS25 mk2 for a number of years I thought about upgrading.  I brought home a demo LS27 for a weekend. But in the end thought t was not worth the upgrade. In my system the LS27 sounded a bit thin to me and lacked the body of the LS25 mk2. It really took me the Ref 5se to convince me I needed to upgrade.

 If you can afford it though I would opt for a Ref 2 mk2. I like the tubes in the power supply. I think they really add something to the sound. 

 Either way I think you will be amazed at the difference. Preamps have come a long way even in the last 5 years. The Ref 5se continues to amaze me every day. I like it so much that I upgrade my phono preamp to the matching Ref Phono 2se