Luxman m-900u owners - quick question

I am currently using the M-900 U , just turned it off. I had the preamp first  and just got the amp 2weeks ago  and still have questions. First if a AB amp has to run so hat why design it in such way that it delivers only 12 or 18 in class A. Is it just to adopt the hyper-modern look and restricted ventilation?The  Amp sounds very detailed and solid  with no harshness  Still under evaluation with his Luxman peers . I am a dedicated Luxman fan This amp  is playing substitute to a pair of M-5 run in Vertical bi-amp( 1 stereo amp on the left the second on the R)
cannot afford 2 M-900 U now. !!! This set up alternates with also two M-05 100 pure Class A run the same way or at time two Accuphase P-102 .  I just got rid of two old  M-22  used in the same set up on the speakers that I have for 17 years the Piega. C-35 . Still evaluating . I do not believe in reviewer like statement best amp  ever At this level  great amps may differ in some points may be this is all there is to it at this level of High-end. Believe me the tonalité and the thightness of the bass and mid bass with the 30 watts class A Pioneer M22 is not something to sneeze at even at this level

I am currently using the M-900 U , just turned it off. I had the preamp first  and just got the amp 2weeks ago  and still have questions. First if a AB amp has to run so hat why design it in such way that it delivers only 12 or 18 in class A. Is it just to adopt the hyper-modern look and restricted ventilation?The  Amp sounds very detailed and solid  with no harshness  Still under evaluation with his Luxman peers . I am a dedicated Luxman fan This amp  is playing substitute to a pair of M-5 run in Vertical bi-amp( 1 stereo amp on the left the second on the R)
cannot afford 2 M-900 U now. !!! This set up alternates with also two M-05 100 pure Class A run the same way or at time two Accuphase P-102 .  I just got rid of two old  M-22  used in the same set up on the speakers that I have for 17 years the Piega. C-35 . Still evaluating . I do not believe in reviewer like statement best amp  ever At this level  great amps may differ in some points may be this is all there is to it at this level of High-end. Believe me the tonalité and the thightness of the bass and mid bass with the 30 watts class A Pioneer M22 is not something to sneeze at even at this level. My question any idea why this 900-U run so hot as a AB amplifier most good amplifiers have their first watts in A nothing new here Why it gets so hot?

@mocassin2     Congrats. on having such a fine amplifier!  Luxman gear is very robustly built all across its product line.  I have the E-250 phono preamp and it really allows me to hear the best that my vinyl has to offer.
As far as the M-900U running hot, I would be shocked if it didn't.  For an amp that's putting out 150 watts/ch. into 8 ohms to be able to put out 1200 watts/ch. into 1 ohms it is a very high current design and thus will run hot.  Looking at the chassis on the Luxman site, the heat sinks though heavy duty, are encased inside a thick aluminum shell.  So the heat being dissipated by the heat sinks is trapped in the amp's casement and thus makes the chassis hot. 

The good news is that Luxman must know that their amp. will be on the hot side and therefore have designed the amp's components to be able to work appropriately at that greater temperature.  My amp runs on the warmer side, making my listening room comfy in the winter months.  As for the summer, thank God for air conditioning.😛

a truly great amp. if you can afford a c900u you’ll never look back. please don’t use a dac direct into this amp. just doesn’t sound comparable imo. and please don’t consider a mac pre with this amp. it deserved better. 

@4425  What about a more neutral and quieter preamp, instead of the Luxman c900u, such as the Benchmark LA4 or Mola Mola Makua preamp. It is not so much a question of funds for me but the issue of number of boxes in limited space. I heard the c900u + m900u and it was amazing. 

Someone did tell me the Makua sounded better with the m900u than the c900u but that opinion is a bit biased.