I never heard the Bel Cantos, but I run a Spectron Musician III mk2. (v-caps) with my HT-3s.
The sound is wonderful. Run them with a good tube pre-amp and you will love the sound, effortless,dynamic,transparent, with very nice tone and texture.
Class D gets a bad rap for sounding thin and dry because they are truthful, IMHO. Use some gold cabling and high quality gear and you will be rewarded.
Spectron right now is running some specials, check it out on their website. I am not affiliated with the company just a happy customer.
Joe