Standmount speaker recommendations for vintage amp

Dynaudio Evoke 20 was my choice (for my 45 year old amp) after trying 6 different set of speakers, very happy with it

From personal experience: the height of the speaker stand is a relationship based on your seated ear height from your listening chair and the height of the center of the tweeter on said stand. An easy way to get in the zone is while playing music raise up, then scooch down several times until you lock it in. Best if you have someone next to you with a tape measure to mark the height from the floor to the middle your ear where the music sounds best. Consider that few stand speakers are the same height therefore their tweeters are located at different heights above the speaker stands resting plate

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What kind of music do you like? “don’t slay me people!” Tekton Monitors would be my choice in that price range with that amp. Maybe some used Focal Electra Monitors but not sure that amp would be clean enough for them. 

KEF LS50 is an obvious recommendation, but it may be too demanding of signal chain and source material for some. In that case, the KEF R3 is a little easier to live with, has better bass extension but still has the precision that comes from the UniQ driver. I've heard nothing else in its class I'd like more, except maybe Magnepan .7s. Honorable mention to Monitor Audio Silver 200 and B&W 706S2