High end tube Preamp under $4k used that competes

If you can live w/ RCA-only inputs/outputs - Conrad Johnson CT6.

BAT preamps have always had that dark/not dark debate for some reason, I can't really understand why though. I have had the VK-31SE, VK-50SE, VK-51SE, VK-3iXSE and VK-32SE in my system, and I would say that BAT preamps are on the darker side compared to preamps from ARC, Aesthetix and VAC. I would say the BAT is not as dark as preamps from Cary or CJ though. I also would say that BAT has the best bass of just about any preamp I've owned, tube or SS.

The VK-31/32SE have RCA and XLR inputs. The 32SE has more midrange bloom, the 31SE has better dynamics, FWIW. Personally I prefer preamps from ARC, Aesthetix and VAC, but my list of requirements is different from yours. So reading your list of requirements, I'd recommend BAT.

Cheers,
John

Sorry, senior moment. Meant to write CJ CT5.

Emotive Audio Sira should be on your list. I don't own one and I don't have any ties to the company but check out the website and call Fred and he will give you some great friendly advice on his designs. There is actually one here for sale - not mine - not any one I know either. A buddy of mine has one and it is an excellent preamp, well designed and very well built, plus customer service is the best also. If I was employed, the Sire would be mine.

The Sira has eighteen tubes. Rather daunting for a guy who just entered the tube preamp kingdom.