Amp and Preamp recommendations for Yamaha NS5000

Luxman m900u looks good. Going to take a hard look at it.
Also musical fidelity seems a great value thanks.
And ya I agree it seems these are speakers that need power so I am confused by the recommendation of 25 watts per channel class A? Just because I am in a smaller room. Wouldn't that still impair the full voice of the speaker even at low levels?
I admit 1 problem I had with the speaker is the soundstage tends to collapse a bit at low listening volumes so I do wonder if a higher quality amp can fix that. Might just be inherent in the design?

There is nothing in the measurements to suggest that the NS5000s need a lot of power.In fact they indicate the opposite.I do suspect however they might be better with low /no negative feedback lowish damping factor amps.A medium powered push pull tube amp even.

@jtgofish  Can you elaborate? Are you referring to the impedence curve? Also thoughts on Yamaha saying 'normal input 200 watts'.

@smodtactical

Since someone above mentioned the Luxman spearates let me chime in since no one asked :)The Luxman separates are amazing and was going to be my choice for the NS 5000. However the following issues made made get a different preamp.

1) The Luxman c900u is big
2) The Luxman c900u supposedly require decent XLR’s (so $$$)
3) I want to keep my preamp far away from the amps since I do not have that much space (15 foot XLR’s). I do not want too much stuff in-between the speakers.
4) I am not that much of a tube fan and the c900u sound kind of tubey to me. I know the c900u is SS internally.

I was conflicted about not getting the c900u and pairing with the m900u since it is a natural pairing. However, I decide to get the super transparent and neutral Benchmark HPA4 preamp instead of the Luxman c900u preamp since it does all 4 of those items listed above better for my needs. My virtual system photos shows the slow progression of this system build out.

I will pair the HPA4 with the Luxman m990u or maybe even the new CODA as my second choice amps. Who knows maybe they become my #1 choice for amps on the Yamaha.

Yamaha demos the NS 5000 with their new 5000 separates. This is the combo I heard them with. The Yamaha separates are $10K each vs $15K each for the Luxman. You should do some research on the Yamaha 5000 Series amp and see what specs Yamaha decided was needed for the NS 5000. The sound was a bit like the Luxmans to me but I could not really tell if I preferred the Yamaha separates because my demo was in a bad room.

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One thing I remember reading on some amp review was that a bigger power amp can benefit the speakers when playing at low volumes. I think it was a Hegel 590 review that was talking along those lines.

Yes the impedance curve ,phase angles and reasonably high efficiency indicate the NS5000s should be quite easy to drive .
They are nominal 6 ohm and do not dip below 3.7 ohm.Most 50 watt amps will be comfortable driving that sort of load.Not dipping below say 5 ohms would be better still but many modern speakers dip down to around 2.5 ohms which really is a tricky load. 3.7 is very benign compared to that.A lab report here where they make this sort of conclusion.The nominal 200 watt thing really means very little as it is nominal.-http://livingsoundv.wpengine.com/wp-content/uploads/2017/01/Yamaha-NS-5000-review-hfnews.pdf