Best amp for $550 to mate with the following...

Here are few that would be close to that price:

Classe 10 or CA100 (as Ray mentioned), the Seventy IMHO, wouldn't be enough power for your speakers which are 86db.

Sonographe SA250

Odyssey Stratos

Parasound A23

Emotiva has several amps that would work well.

Go to Class D Audio's website. You can buy a complete amp, a complete kit, or amp modules/power supplies. In any case, they are an indredible bargain, beautifully made, with high quality parts (in the USA), and are one of the best sounding amps I've ever had, after 40+ years at this.

Better than VAC, Plinius, Aragon, Parasound, etc.

Dan

add $1...200 and you'll get Bel Canto S300 little amp. this one indeed plays music!

If it is possible save up and hold off and get a new Odyssey Audio Khartago for $995.00. Factory direct ,30 day return, 20 year warranty, made in USA. You would be better off in the long run than buying some older amp that might end up giving you a headache down the road. Check out their site!

An Emotiva amp would be a good, solid choice. The XPA-200 would work quite well for $499. Plenty of power and a great warranty.

https://emotiva.com/products/amplifiers/xpa-200