Best integrated/power amplifier under $6000

@audiolabyrinth  Interesting comments on the Luxman 509x. I auditioned this integrated recently with a Luxman DAC + TAD ME1 speakers and I would not categorize the sound I heard as you described. I switched over to the Luxman separates and it was significantly better than the 509x but the 509x was rather good.
 
Your Krell 300i is getting some love at the Munich show. I might need to have a listen to this new Krell XD designs before I lay down the dollars for the Luxman m900u amp I plan on buying. 

https://www.stereophile.com/content/krell-k-300i-integrated-amplifier-sonus-faber-olympica-iii-loudspeakers-zensati-cabling

Parasound Halo JC 5 Stereo Power Amplifier around $6000

https://www.audioadvisor.com/prodinfo.asp?number=PAHAJC5

Kinki Studio EX-B7 monoblocks around $3400

https://www.mikepowellaudio.com/shop/kinki-studio-ex-b7-solid-state-monoblock-power-amplifiers

NAD C 275BEE power amp around $1300

https://www.crutchfield.com/S-eRk8yhYMPti/p_745C275BEE/NAD-C-275BEE.html

audiotroy, I did not get the Krell with the digital board, I have a digital board in the ps audio direct stream memory dac and matching transport with up graded snow mass soft ware, the Krell and everything else  has dedicated lines with furutech gtx-Rhodium d outlets, and $8,000.00 a cord Tara Lab's cobalt reference power  cord's ,  all mated with Tara Lab's muse speaker cable's and balanced  interconnect's,  with magico q3 speaker's,  also jbl L1 book shelf speaker's,  I switch back and forth between the speaker's .

yyzsantabarbara, the Luxman L-509X integrated amplifier did not ever sound different from new out the box to 600 hrs, the Krell continues to get better from new to  300hrs and continues burn in , the Krell kills  the Luxman with uncanny clarity,  mid range,  sound stage size and depth, bass, and does not distort at loud volumes as the Luxman gave out at large volumes with distortion,  the k 300I best suit is clarity without losing musicality,  and the sound is not warm, rather in between warm and cold, the other mention here is I don't get listener fatigue with the Krell like I do with Luxman,  the Rega osiris was a nice sound but didn't have the treble detail or the clarity as the Krell, however,  the Rega sounded better than the Luxman,  reget selling the Rega,  didn't need two integrateds, cheers. 

@audiolabyrinth  Thanks for your feedback on the Krell vs Luxman. I have 12+ hours to kill in Los Angeles in the first week of June. You have now given me something worthwhile to do. I know where to hear the Luxman but need to find a Krell XD on demo somewhere.