Bat VK-31SE vs. 51SE. Sonic differences?

What does the VK-51SE offer in comparison to the 31SE? I was wondering if it would offer a little more of an extended and airy presentation through the treble, and a bit more speed and transparency? Anyone had a chance to compare the two? Thanks for any help.
I have had a chance to compare the two side by side in my system. I have owned a V-31SE for about a year and had the VK-51SE for 2 days courtesy of my friend. The VK-51SE sounded like it had a slightly more deeper, articulate bass over what is already very impressive in the VK-31SE. In terms of transparency and "air", yes a tiny amount as well. Truth be told, it was not a night or day difference, they are very close to my ears. If your system has the ability to resolve the slightest differences, maybe the difference in price would be worth it, otherwise spend the difference elsewhere in the system.
Hi, I had a 31se in my system while my 50se was getting upgraded to a 51se. The 31SE hand down beat the 50se. The 51SE is similar to what flyski says above, however, I'll take it a few steps farther... I think it is deeper and more extended in the bass, by a little larger margin. More detail across the whole spectrum. Lower noise floor, better staging-wider and deeper. More natural flow to the music. The top end really shines. Goes on what seems like forever. More weight-wetness in the mids and the top end. Better detail, but more natural. Finally, dynamics are better. More pop to things. In the top end for instance, when a stick hits a more disincly hear the impact...then the decay...

All around better. I think it's well worth the extra $$'s. But I do agree it's system dependent. If you have the system now or plan to then you really should go for it.

My Wilson Watt Puppy's are very revealing and I definitely hear the improvement. Especially on hi rez sources like vinyl and SACD.

If you primarily listen to standard cd...maybe these differences are not as pronounced.

With all this, I still think balance is important (unless you're planning for the future). The 51SE can't be any better than what's input into it and the amp has to handle what the 51SE is sending it...ditto the speakers...

Sorry, but your checkbook is the only one that might say something. Go for the 51SE.
Right now I am using a
VPI Scoutmaster w/ dynavector 17D2MKII cartridge and modified P75 phono stage.
A Sony SCD-1 for SACD, and also as a transport into a special edition Audio Aero Prima DAC for redbook.
The amps are Parasound JC-1 monoblocks and the speakers are Legacy Signature IIIs.
Cables are either Siltech or Bogdan Audio
I am in the process of upgrading my digital source now and hopefully my speakers by the end of the year.
I have been through the preamp on my Audio Aero, VK-31, AR LS-25MKII, Aesthetix Calypso, and now the VK-31SE.
I love the BAT from the upper midrange down. If the VK-51SE can add some sparkle to the treble and match or better everything else then its what I am looking. I thought the Calypso was very good but it couldnt match the BAT in terms of bass and midrange. I liked it more from the midrange up. In the end, after several tubes, the noise started to bug me. Any other suggestions would be great.
Happy Easter!

Hello Tom,

The 51se is more extended then the 31se on the top end with more resolution of finer detail but at the same time it's not as bright. The mids are richer and more vibrant in texture, the bass goes lower with better definition. Soundspace is more vast with more air on the right recordings. More dynamic!

IMO the most stricking quality the 51se has over the 31se is a sense of ease from top to bottom. It just does everything in a more relaxed manner but at the same time it's sounds more compelling with even greater resolution.

I think a good anology would be .... A car with a 6 cylinder engine can get you up the hill but an 8 cylinder car will do it better and make it seem easy.

Good luck!
Well...great system! I don't like to give direct advice, but the 51SE will stay in you system as a corner stone for years to come. Given what you are saying, it's the choice. I've heard the Calypso to...similar findings-it's a steal for the $$'s, but I just like the ease and weight the BAT's give.

I've had my 50SE and now 51SE for 6+ years now. Everything else has changed..amps, turntables, digital, phono stages, cables, speakers...except for it.

I don't see this changing in my system. I'll keep improving the source stuff first...then maybe speakers...not the 51SE.
The pricier one provides more money for VK to rant.
Hello Tom,

I owned the 31SE for 2 years after going through various ARC preamps the previous 15 years. And having heard the Calypso (with NOS tubes) in my system, I agree on your assessment: I much prefered the 31SE on the lower half due to its greater portrayal of space and decays and midrange fullness, but the Calypso brought so much more detail and openness on the top. It would be a tough choice here coming down to one's priority for one set of strengths over the other.

I seriously considered the 51SE but once I dropped in the Aesthetix Callisto Signature, there was no desire to continue the preamp quest. With the LS5 II over the SP-10, the LS5 III over the LS5 II and the 31SE over the LS5 III, each had been marked improvements over the predecessor. In the case of the Callisto over the 31SE, the Callisto was simply in a whole new class altogether....and this was with the stock Sovtek tubes. I had not heard such a difference since I first heard the SP-10 pretty much destroy all its competition back in the early 80s. To try and describe the refinements here would not do the Callisto justice. And then to replace all of the stock tubes with various Mullard, Telefunken and RCA's, the Callisto improves by nearly the same magnitude. This is simply not an option with the super-tube based BAT models. And once I got super quiet tubes in the Callisto, it was just as quiet as the 31SE. I had both for a couple months until I sold the 31SE.

Not having heard the 51SE, I have no direct experience to the relative improvements over the 31SE. The previous posts here have given us an idea as to the improvements with the 51SE. And it is good to learn that the 31SE's soft top end has been improved with the 51SE. But my gut feeling is that the benefit here is on a similar level of improvements I heard with my previous preamp upgrades.

Yes, the Callisto is a pain with its 2 or even 3 chassis, the multitude of tubes, its clunky volume controls, and the lack of the super cool user interface and multi-function remote of the BAT. But once you hear this new level, you quickly do not care about losing the features of the BAT. I would love to find a full function preamp to get rid of the multiple chassis Io and Callisto but until something more compact comes even close to the performance, I will put up with the hassles.

The 51SE seems to be selling in the $4500-5000 range on the used market. I have seen the Callisto Sig with one PS sell in the range of $5500-6000. For $1000 more, I think it would be worth your efforts to try and hear one before you lock into the 51SE.