What Audio Research preamp would be an upgrade to my LS2B

Kenny,
I always liked the ARC products and I am happy with the LS2B but the bug has me wanting more? As far as budget I will pay for the right fit. The LS2B is the Mk 1

Lostbears,

It was from someone like you that I was looking forward to hearing from. Thank you for your input because you know the LS2B and made the move. I haven't heard the LS25, but you say it is a big improvement Oh boy! 
 

(((LS2B but the bug has me wanting more? As far as budget I will pay for the right fit.))
 Take a listen to the new LS 28 I have compared the various ARC line stages over the years although always decent the latest group ac-cells well beyond what was ten years ago or even more recent years efforts.
 Best JohnnyR
 ARC dealer

 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

I have a VPI table, the ARC Ref3 and ARC PH7.  The amps can be had for under half price used and while they may be the red haired step children by todays standards, they are extremely good and good value.  I love being able to tube roll the PH7.