Amp and Preamp recommendations for Yamaha NS5000

A Supratek DHT preamp would do the NS5000s justice.Say a Cabernet 300B/45 .Well worth trying with your Bryston power amps.

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.

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

Only if you are silly enough to turn it up full.Do you drive your car at its maximum speed?That could be dangerous too.The Magtechs are nice sounding power amps .I heard them with a Supratek Preamp and that was a very good combination.Of course they are designed to drive low impedance electrostat speakers but that does not mean they would not suit the Yamahas.

I have heard them sounding superb with the Yamaha AS 3200 integrated.Maybe too obvious?