Just came across this thread. I have the XA9000ES and a STRDA9000ES receiver. I had been using a 777ES receiver for years, with great results! I still have 2 777ES receivers, one that the 9000 replaced, and 1 still in use (with Belle Klipsch as L,R fronts and Klipsch Cornwalls as L,R rears). The STRDA9000ES and XA9000ES have the unique ability (there are a very few other firewire compatable pre-amps/receivers) to link with one another for SACD playback. The DSD signal from the XA9000ES passes into the receiver, remains in the digital domain (because of the S-Master Pro digital amplifiers in the receiver) until a conversion just before hitting the speaker wires. Now in my case, I use a TAN9000ES in BridgedTranformerLess mode to drive my L,R fronts because although rated at 200 wpc (just like the 200 wpc rating of the receiver's 7 digital amps) I prefer that sound ("warmer") to the internal L,R digital amps. SACD sounds incredible on this combination, with 2ch and multi-channel SCADs! I have 3 Klipsch Legend KLF-30s across the front, a pair of Heresys for front side surrounds, KSP-S6 rear side surrounds, and AW600 rear surrounds (for now) along with a Definitive Technology Trinity subwoofer. I have NEVER been listening to music or watching a movie and thought to myself "I wish..." or "If only..." This system sounds amazing at all volume levels and will play as loud (while staying clean and clear) as anyone could possibly desire.
