Summary:
In short, this unit is currently my favorite component in my system. I purchased it with the remote and Six-Pak oil-filled capacitor option ($500 for each option). I have never heard a smoother, more liquid presentation on a SS preamp than with the VK-40. Highs are unfatiguing, midrange is well-defined, bass is tight and controlled. There are no weaknesses in both its performance and its ergonomics. I consistently preferred its sound to various Levinson, CJ and Krell pre's that I heard. It really is in a class of its own. It's definitely worth its retail value, and even better if you can find a used or demo unit.

Associated components
BAT VK-40
BAT VK-200 (100x2)
Eggleston Fontaines
REL Strata III
Sony DVP9000ES
MSB Link III w/upsampling
Harmonic Tech Pro-Silways, Pro-11's throughout
Monster HTS2500 power conditioner

Strengths:
Musicality

Weaknesses:
None

Price Paid:  $4500.00 from BAT dealer

Summary:
I've waited an entire year to sample a BAT VK40. Finally purchased one recently and it was worth the wait. Everything the 30SE provided and more! Seamless presentation with VTL Deluxe 140 mono's, Pass Aleph Os amplifiers at the moment. Next step will be to integrate another BAT VK500 into the system (3rd time around). But my first impressions of the VK40 are so very positive that I believe I've just purchased my last solid state preamp ever. Nothing like having tubelike performance without owning actual tube components. Many suggested to me they believed the VK40 to be the unsung hero of the BAT preamp offerings. I'd have to conclude that I'm of that same group of believers. I've owned many a BAT preamp, and the VK40 is as good, or better (IMHO) as I've heard.

Enjoy!
coltrane

Strengths:
Dynamics, detail, smoothness, quickness, tubelike presentation.

Weaknesses:
None observed as yet!

Similar Products Used:
BAT VK5i, BAT VK30SE, BAT VK20, Pass Aleph P, Coda 01P, Threshold T2 and T3 preamps.