Older or Modern amp for older Speakers (NHT 3.3)

Check out the Odyssey Audio Khartago!
http://www.odysseyaudio.com/products-khartago-stereo.html

Even that old Adcom can be had for a song. I just recently sold mine, and it still worked like a charm.
The Hafler and McCormack seems like it would be a good pairing. At least, to me.
B

Had the NHT SB 3s and used them with a Prima Luna PL2 integrated.  Depending on the source, like a movie DVD, the PL2 would run out of gas.  The NHT 3.3 is the much bigger brother.  

I have been using the Class D SCA 250 amp ($500) for the past year.  Plenty of power.  Very musical.   

https://classdaudio.com/cda-250c-class-d-audio-power-amplifier.html

No desire to get into the Class D debate.  

Rich 

I've had great luck running Threshold amps. Presently using a 550/E. Wonderful amp

Used to work at a store part time that sold the NHT 3.3 and we used the McCormack DNA 1 and Aragon 4004 and 8008 on those speakers. The McCormack was definitely the better of the two, but the Aragon’s definitely gripped the bass on those speakers but the McCormack a more refined amp. Usually it was a DNA 1 Deluxe. If you’re not going to send a McCormack into SmC for the full monty upgrades which will cost you, expand your budget a little and look for a ARC 100.2. The 100.2 is a great amp that I think will be a nice match for your 3.3’s as I recalled  can sound a little hot on the top so I’d avoid a sterile/cold sounding amp.

Definately moving out of your budget more, but the Parasound A21 would be a nice amp as well.