The past 2 weeks, I have had the opportunity to audition the Luxman 509X and 590AXII integrated amps at home on my system. One is a pure class AB and the other is a Class A, respectively. Both Luxman products have received nothing but rave reviews. I was very grateful to be able to try these two out as I had a bar in my mind that had been set by my Line Magnetic 805ia. That bar was very high as I am of the opinion that it is clearly better (to my ears) than other amps that I have heard previously. That includes the Primaluna Dialogue Premium HP, Hegel 360, McIntosh MA (forget which one I had heard), Naim Supernait 2 and XS 2. The 509X has all the power to handle just about any speaker you throw at it. The sound was very smooth and effortless to my ears without sounding too dry/analytical. While I wouldn't call it overly analytical, I would say that the music reproduction was very detailed, fast, and it had great controlled bass. I would also describe the amp as being very dynamic and exciting to listen to. I suspect most people would be more than happy to call this their end game integrated amp. The 590AXII is Class A up to 30W and then extends further into Class AB up to about 90W per channel. If you have decently efficient speakers, you would be able to hear the difference between the 590AXII and the 509X. Class A just has a sweeter and slightly warmer, rounded sound signature to it that makes the music sound just that little bit more engaging and enjoyable. To my ears, it has all the great qualities of the 509X but more of that euphonic quality that is so hard to describe. It does get hotter than the 509X, being Class A, but it is by no means anywhere near tube heat. I sometimes switch back to the 805ia to see if I can hear a big difference. Last night, I swapped the 590AXII for the LM and the difference is still fairly evident. The LM sound is just so sweet, engaging and reaches you at a level that can't be described. Maybe it is an extension thing or maybe it's a tube ephonic/holographic quality but the difference is there. The Luxman amps have LOTS of fantastic qualities though as it is built to last forever (seriously, the build quality makes you proud to display this amp), sounds amazing, has a headphone amp, has phono and balanced inputs, does not produce as much heat as a tube amp and you don't have to worry about tube life/maintenance. Seriously a hard decision if one were to decide between the LM and a Luxman. Is the Luxman better than the LM (with rolled tubes)? No - if anything, from a pure musical enjoyment perspective, I might enjoy the LM just slightly more. But when you consider the whole package value proposition, the gap closes and may put the Luxman ahead.