ARC LS-5MKIII or ARC LS-25MKII

I also like LS5, still have LS5II playing at my home. On the contray as John, I did try BAT 31SE but keep LS5. Maybe LS5 is better match to my system, and I like sound to be a little warm. BAT just remind me too much of a ss.

My experience is with 30SE not 31SE, sorry for the error. BAT is a very good preamp, in several ways it is better than LS5. Bass is better control, I think, that's why John hear better image across spectrum on the demo. Overall it is more transparent and has very refined top end and bass control is top notch for a tube gear. LS5 is more bloom and lush in the middle frequency, and I am a middle freq guy and not care so much about details or air. I prefer that warm sound of LS-5 or SP-10, to me this is the "tube sound". I did not mean BAT sound like a bad ss, but I mean a good ss. Just different flavor, I will compare BAT xxSE to the highly regarded C-J ART-I (ss) or Accuphase top end preamp. Many good ss preamp sounds awesome too.

Hi, I had LS-15 before and thought the mid sounds better after infi-cap upgrade, and remember to put in SIEMENS tubes(try bugle boy if you want warm sound LS15). The bass is not as full and musical as LS5. BAT 30SE's bass is not as loud but a good control. AT some point, I have LS-15, LS5, and BAT 30SE at home. LS5 and early LS-15 came out before this power cable thing, so change it to IEC for experimenting power cable would be fun. That's my next plan. One good (yet bad?) thing about 6922 is that there are so many different brands you can try.
BAT you can try different cable even their web site said no difference (to my ears they are less sensitive to power cable than LS15, but I won't say no difference).

John, thanks I will audit 31SE if having chance. LS25-II has a astonishing bass (I hear once in dealer place), and it seems quicker and share some charater with BAT (they all use 6H30 I think, maybe I am wrong). The gear then is so different from mine, so I can't comment too much without living with LS25 for some time.