I had the pleasure of having this amp in my rack for a few days and I must say the experience was absolutely worthwhile. I took a ton of notes when listening but I think I would prefer to spare you guys the details and stick to the things that I felt deserved the most mention.
Dedicated power line feeding OneAC Isolation Transformer
PS Audio Perfectwave DAC
Stax Omega II mk1 (009 + OIImk2 briefly)
Stax SRM-717 US Voltage
DIY XLR Interconnects - Canare Quad w/ Neutrik XX Ends
Shiny discs (I use a mix of good and crappy mastered music): Slayer - Reign in Blood, Megadeth - Countdown to Extinction, Rilo Kiley - Under the Blacklight, Miles Davis - In a Silent Way, Angelo Badalamenti - Fire Walk With Me Soundtrack, Daft Punk - Discovery, Lacuna Coil - Dark Adrenaline
1) Build Quality - I've never owned or have seen any Cavalli products in the past, but as I think has been mentioned before, the pics really can't do the LLmk2 justice. The finish is to my eyes impeccable. Prior to receiving the amp, Alex sent me a laundry lis of things that were inherent flaws to this pre-production model. I felt like I'd be getting a box of parts at first, but after unwrapping the box I was not only pleasantly surprised but the amp clearly exceeded all of my expectations in terms of build. In first use you must plug in a power cable, flip the switch on the back, and a pleasant white light will show power on the front. Touching (not depressing) the power button will illuminate the on light. The amp doesn't generate any heat (or very little) when it is not powered on but gets pretty hot after about 30 minutes of warm up. Along the casing's top and bottom are a generous amount of slits for ventilation and visible are many heatsinks on the interior (they remind me of the sinks found on b22's), I had no concerns over the amp's amount of heat but would recommend a fair amount of breathing room for this amp.
2) Source quality - On the first night I went straight from the balanced XLR analog outs of my Sony xa5400es SACD player. In hindsight I think this was a mistake. The Analog out of the Sony was passable but IMO going through my PS Audio PerfectWave DAC with the Sony as a transport only resulted in a noticeably beefier and fulfilling sound. In my use I only used XLR inputs of the LLmk2 but it features 2 sets of XLR inputs 1 RCA input and 1 XLR loop out. The loop out I would definitely see being very useful for headphone listeners so that you can a/b other stat amps or balanced amps. If you want RCA loop out I think you would have to adapt the XLR's to achieve this. At any rate, make sure you've got your best in terms of a source as the LLmk2 easily revealed flaws in my setup.
3) Sound - Love at first listen. You may find impressions of the Omega II's which describe them as dull, dark, veiled, etc. In my experience this is clearly something that you will find when the Omega II's are underpowered. This is not the case WRT the LLmk2; the second you are jacked in you will know that the Omega II's are being fed some serious juice. In comparison to the SRM-717 the LLmk2 was clearly a step up in every way possible. To put another way, I've heard that with the Omega II's it may take a marathon listening session to "get" the magic out of them but I found this was not so with the LL.
For volume or gain, comfortable listening for me with the Omega II's and LLmk2 was around 9 o'clock. With the 717 it was closer to 11 or 12 o'clock.
The LLmk2 will not transform the Omega II's into something they are not. I get the impressions that it is a little more colored than say the KGSS from my memory, but I would not say that this is at all a detractor. I found that with my Omega II's that the claims of neutrality are all true, there is no evident bump in bass or midbass, sub-bass was present but not massaged. There may have been a tiny bit of treble sparkle but nothing I would call unpleasant, perhaps it was result of crappy recording. At a certain point I felt that certain parts of my music were more distant than I wanted them to be, like maybe they were present but not fully accounted for. When I came to these findings I felt a little bit let down by the Omega II's and at this point I had not yet heard the 009's but I was picky about what I would call a somewhat constricted soundstage and not enough oomph in the areas where I wanted.
4) Enter the 009's - Many thanks to Rico613 for driving down to share impressions with me on the amp and to let me hear his Omega II mk2's and 009 for the first time. I'm sure he will chime in with additional findings as the amp has now passed along to him for further auditioning! In short I think we both felt the 009's were a great improvement over the OII's, the question of value was probably more pressing as the OII's weren't bad by any means. Sadly I don't think either of us were able to properly fit the OIImk2's because there was too much clamp and not enough elasticity in the headband; as a result no true seal could be made!
The areas I found the OII's lacking in I would say the 009 had addressed properly; primarily that the soundstage was immediately more impressive; like a small room versus an open stage. I found too that the issue of present but not fully accounted for was no longer a worry with the 009's. When the 009's sat on my head I had no worries about what I was hearing, no dissecting of deficiencies or squirming from the fit.
I didn't have much time with the 009's and the llmk2 but I can say with confidence that to my ears I would easily rate the 009 + llmk2 the winner of the bunch.
5) A word on vendor communication - Even though I have only auditioned the amp for a short period I had many back and fourth e-mails with Alex. I found him very easy to get in touch with, pleasant, helpful, and trustworthy. I think this speaks volumes about a brand/manufacturer and Alex has again exceeded my expectations here.
In conclusion I would say that if you are in the market for an electrostat setup or an upgrade you owe it to yourself to try something better than the stock Stax amps. In my mind the LLmk2 is a heavyweight contender clearly besting the 717. Unfortunately I think the price of admission is something that would hold me back a bit. I would have to downsize considerably in order to move to a setup like the LLmk2 and 009 - if I were a one rig type user this combo would be on the shortlist.
Once again, many thanks to Alex Cavalli for making this possible and to Rich for making the drive down!