They have even made minor upgrades over time. Just a great piece. Ayre has a 7 year plus lifespan on their components. They just make upgrades like cars that do mid life cycle refreshes. Don't know how that will be handled now that Charlie is gone (RIP), but they have other great minds at Ayre and I know that they had a bunch of other projects that he was working on. I know that after I got my amp back from the install of the crossover, they sounded even better. Subtle, but real changes for sure.