How good is the BAT VK40?

I had one and sold it after a year or two. It had many great features but the for me the sound was a bit uninvolving and a little too "smooth". It did have a sound similar to the tubed VK-30 I had before that in that it did add a thickness or warmth to the midrange and had a great soundstage. I went back to my old Rotel RC-1090 and am happier because it sounds more immediate in the treble and has a sharper edge on bass transients on electronic music, etc. It might be a great match with your Nuforce amps, though. It all comes down to that darn synergy thing. I do miss the great volume control and adjustable balance on the VK-40.

Bizango, thanks for answering. Yes, synergy is really important, I feel the preamp is the weak/missing link in my set up.

I've heard mixed opinion. Some said vk40 is superior to vk30 or even vk31, and vice versa. I see one sold in ebay at $1700 and one advertised in agon at $2000. I guess the price is not that bad.
I am planning to get vk-30 with phono soon to match with vk-200. I chose vk-30 over vk-40 because I'd like to have tube sound in my system, and also due to the price.
I am not sure how well Nuforce Ref9 would work with vk-40.

I am running a BAT VK 31SE with my Nuforce Ref9 V3 and it is a great combination. Have you considered upgrading the Ref 9 to V3? Magical upgrade in my opinion.

Get a tube BAT pre ;)

Yes, I am going to get a vk-30 pretty soon. ;-)

I've owned the 31se and when I upgraded I auditioned the 52se and 42se at the same time. The 52se was a little more dynamic and detailed than the 42se. The 42se is slightly laid back. I ended up going with the 42se. I think it fit my system at the time better (krell/Thiel) The 42se is quite a bit of a jump over the 31se. Not sure but would think the 40 would be the same over the 30. Although this is without comparing them. Dont count out the SS BAT preamps. They are up there with the better SS preamps I have heard and on par with the BAT tube pres.

For whatever it's worth, IMHO, there's a bias against BAT solid state products in part I believe because BAT cut their teeth and created a solid reputation on the VK5i, 3i, and the VK60 all of which are hybrid tube designs. I'll even go a step further and say BAT's solid state products clearly don't get the recognition they deserve, in part because the average audiophile has no or minimal experience with BAT's solid state gear because they're stuck on tubes. Personally, I became a fan of BAT's solid state gear first before sampling their tube gear. Most acquire BAT's tube gear without even giving BAT's solid state gear a fair listening. Bias towards tubes is no surprise when it comes to audio. I came to BAT by buying a used VK200 amplifier years ago just as an experiment to see if this small amplifier had the capacity to drive my CLS's, which most know is a power hungry and demanding load. To my surprise, the VK200 drove the Logans with ease, and very dynamically. But then of course I had to sample a VK500, which was but more of the same. Having a personal friend as a local BAT distributor I've owned the 30SE, 50SE, and I now own a VK40. It's performance within my system performs so well that this is the second VK40 I've owned. One of these days I'll tire of sampling new gear and I'll settle with a VK40. I've done blind tests of the VK40 against a VK51SE, VK31SE, and it's my opinion 9/10 listeners would say hey it's like splitting hairs, because the same dynamics, authority, reserve power are all there. Does a 51SE provide $2k more in performance level than a VK40? That's a question most won't allow themselves to answer for the reasons I've already suggested...they're stuck on tubes. Cutting to the chase, the author mentions getting a VK40 because it's "at a good price." And the price for used 40's are low in comparison to BAT tube pre's because of a lack of familiarity with BAT solid state pre's. A 40 is as good as anything Pass Labs, or certainly Mark Levinson has developed. And yet even those two solid state offerings get more respect than BAT. Perhaps because neither the PASS or ML has a competing line of products that run against it. In any event the 40 is one heck of a buy, and certainly worth sampling at the low entry price to sample one. Enjoy!

I currently use VK42 together with VK250 to drive my Monitor Audio PL300 and can recommend BAT solid state from my own experience. Fluid, dead silent and dynamic sound. Opposite of harsh. I had VK40 before VK42 and it was of similar character, but less dynamic and less bassy. Its sound was even more smooth and liquid than VK42SE in my experience. You can not go wrong with either of these.

Coltrane1 I agree with you for the most part but I have listened to the VK40 at the same time I had a VK5i and preferred the 5i simply because it had MUCH better midrange and topend extension. The 40 was faster and tighter but did not have the midrange bloom tube products are noted for. If I were to buy a solid state preamp then I would buy the VK40 no doubt. I preferred it over any ss preamp I have heard or owned.

Samzx12 I neglected to mention that my first tube preamp was the VK5i, which I owned at the same time as a Threshold T2, a flagship preamp from Threshold. I loved the 5i, and had a very difficult time parting with it, but in the end BAT's new user interface won out so I sold it to sample a VK30SE. It's very likely the satisfactory results I've been able to gain with a Vk40 in the loop have as much or more to do with my choice of loudspeakers. I'm running dual subs with CLS's, which are midrange/topend heaven for most audiophiles, and the end result is a positive one no matter what preamp I enter into the system. Although, I've never had anything less than what most would consider as a quality component/preamp within the chain. As always, results vary and are entirely dependent upon ones entire system. Enjoy!