@drubin - That’s a great question. In my experience, I never could get the HS to really sing at lower volume with any of those other amps. I once tried them with the Luxman 509 amp, which matches the power of the Gryphon, but felt the combination was too bright.
So to answer your question, the Gryphon Diablo 120 does make the HS play well at medium and lower volumes. I don’t feel like I need to crank things up to get the beauty of the speaker.
This journey of diving into audio has been an adventure. The first thing I bought were the Dynaudio Heritage Special speakers. For awhile, I regretted not purchasing a higher sensitivity speaker. Paired with the Gryphon I have no desire to seek or upgrade. For the record, I’ll keep my QLN Prestige 3 speakers and drive them with the Conrad Johnson Classic 120 and switch that system in every few months, but it’s hard to beat the synergy of the HS with Gryphon.