While both the BAT and ARC are fine preamps, having heard both myself I'd say the difference in their characters is very marked. The BAT is very neutral, closer to a really good solid state unit than the classic tube sound. The LS5, on the other hand, is probably the closest thing to a classic tube-sounding preamp that ARC made since the SP10; as a result, it has a lot of admirers. It seems to me from what you've written so far that you prefer the classic tube sound, so I'd suggest you stick with the LS5. Re-capping the BAT will change its sound, but I don't think you'll get it to change its character that much, only improve on its existing character. Just MHO.
Pream question
A few days ago I got Audio Research LS-5 MKII for testing. The sound seems good for me so I decided to buy it. But right now there are two more preamps in the same price range at our local market: Audio Research LS-25 MKII and Balanced Audio Technology VK-51SE. All have quite positive feedbacks... What will be the best choice among these three?
My current system is: B&W Matrix 803 S2, Luxman Da-06 DAC and Luxman M600-A amp.
My current system is: B&W Matrix 803 S2, Luxman Da-06 DAC and Luxman M600-A amp.