Guido, I find my self still unable to answer both questions due to the many significant changes I made to my system due to the installation of these superb little amps. I also reversed my own thinking on the priority and value of a serious, planned, methodological approach to EMI/RF control that was triggered by a surprisingly large and unexpected improvement while engaged in an experiment I had devised to prove to myself that isolation platforms were bunk. I had bought the footers for my TV system's main speakers. I had been intrigued mostly by the beauty of Maple platforms, but figured I had the rack & support concerns covered. Going from such a beginning to giving each box its own 2-4" maple platform complete with decoupling (isoblocks) under each and with coupling provided by Herbie's balls, Mapleshade micro-points and a few exotic material cones made for such a huge improvement in so many ways that I could no longer assign credit or blame to any other components, especially my previous amps that, probably too, would have sounded better in a more mature system.
Further clouding the issue of break-in improvement was my discovery of the value of VTA setting for each album, which I had never quite heard in any previous configuration, even when on-the-fly setting was supported by the arm. Before these amps, I was certain that visually leveling the arm/cart was good enough. Don't worry, be happy. With these amps, I can dial in the perfect height in about 3 or 4 trials while playing many kinds of music. Besides spotlighting the VTA settings, it also makes other arm geometry adjustments results more audible as well, much to the further evolution of my system during the first 1000 hours on the amps. It seems to me that there is some controversy about the value and procedures to set anti-skate or whether to even try on VPI arms. Since I had started to trust my own ears instead of solely on others' experiences, I decided to test it by deactivating it on my JMW by flipping up the little weight bar. After some hours of listening, I forgot about the rarely considered non-sonic benefit of anti-skate control - namely control of wide ranging stylus movement during high-level play of seriously wide bass grooves near the center of the record. I was rudely reminded of this property when I lost all self-control and juiced the volume much higher than I usually listen while playing Telarc's 1812 Overture. So began the separation of voice-coil from cone on one of my vintage Snell's 20 woofers. It took about 6 weeks to locate a sonically identical new pair that had a slightly larger frame diameter, requiring a trip to the speaker shop to have the existing holes counterbored 1/8" larger. While in the shop, they were given a checkup that discovered some separation of diaphragm from surrounds on my midranges. These were disassembled and reglued for all 4 drivers. While it was in the shop, Music Direct offered a few sets of Cardas Patented Binding post demos for half price, so I had them installed. While setting up the speakers again, I accidentally ripped the WBT plug from an early set of Siltech gold and silver interconnects I had been using between the TT and phono stage. The guys at the speaker shop seemed talented enough to trust with a repair, so I sent away for a cryo version of the Xhadow all silver ends and had those installed.
As if these weren't enough confounding variables to confuse any attempt at preserving the old setup for comparison, I also discovered the benefits of anti-static treatment after deciding to challenge Pierre's claims that mapleshde's $40 brush was really better than anything else on the market. It is so fine and versatile that I even use it on the stylus for every side I play - not just the records. When used in conjunction with a record vacuum, the improvement to the low-level retrieval is almost like replacing old records with brand new. while it might seem like a good thing to have all your records sound nearly new after even 50 years, all comparisons die when considering that every record was seriously degraded while listening to both the tube amps and the less broken-in D-Sonics.
The best I can do offer now is that by 300 hours, the amps had broken in enough to be taken seriously as indicators of overall system strengths and weaknesses. By the time several of these weaknesses had been addressed, they fit in very well and do just about everything extremely well. I concentrated on highlighting the effects their high transparency and ease have had on showing me important defects in my system and processes, but this is only one characteristic of this amp that exceeds expectations. This is not a one trick pony. I expect to add a posting or two to describe their musicality, bass quality, and soundstage characteristics as well as a few comparisons of how the system itself sounds when switching them off to listen to headphones when played through an Eddie Current triode amp with LCD-s phones. If i can find a way to repair the Atma-Spheres for less that their resale value (currently around $3k), I will probably do a comparison then, but I suspect that I would probably opt to keep the D-Sonics and sell the OTLs.
