Amplifier for Harbeth 40.2

I heard them at Suncoast Audio with the top of the like MSB Select electronics/DAC and it was beautiful.  I was amazed at what they could do.  The love a lot of power as long as your amp is a good match for them.  I've found Harbeth's to be very forgiving, but will open up and sing with only a few top amps, both tube and SS.  Heard them at Walters in NH too with a couple of amps (Pass was one, but I forget which models and I forget which was the other company, sorry) and it sounded excellent, but not like it did with the north of 100k worth of MSB gear. 

40.2s need POWER! I use them with with Simaudio 400M at my large place but the new Hegel H590 and Gryphon Diablo 300 will be very good choice. I would stay away from Pass Labs for Harbeths - both companies have rather warm sound signature that can just be too much. 

The amplification for 40.2s does not need to cost a fortune to perform very well. 

I would take a good look at Atma-Sphere. Have heard they go well together. 

You can go less expensive on the amps, but NOT the preamp.  They do have more detail than many give them credit for and therefore need a top preamp.

I’m confused when you say that the Luxman “seems less powered”
i believe the M900u is 1,200 watts per ch.