I'm in my first full month with the 509x after running Rogue 180's, PS Audio BHK 250 and even McIntosh 462 as amplifiers with various preamps C2200 and C50 Mc's and others.. NOTHING has compared to this integrated and speaker wise I've used Focal Sopra 3 and recently ML Imp 13. now moving to ML 15's. I'm completely blown away by the Luxman product with regard to quality build and it's transparent sound. My dealer suggested the 509 as everything including the Mc's were way to warm for me and was he on the money! I'm so smitten that I want the 900u amp and 900c pre amp as the dealer say's that I will be shocked how much better it will sound! What's interesting is the review posted at the top of this string states that the 509 enjoys the 900c technology which makes sense based on how it sounds. I'm heading to the 900u first but cant swing these two pieces since the retail for $20k per, however, my quandary is what preamp to use? Dealer recommended the Jeff Rowland Capri 2 or the Bel Canto Black EX (too expensive)? So.. if yo haven't heard the 509 find your dealer and find the money to buy this integrated, you will NOT be disappointed! Any preamp suggestions are welcomed.