Hi Ola, your speakers are very sensitive towards quality amplification. I heard a pair of AVG's hooked up to Audio Note Oto SE's. The sound was simply unacceptable - not transparent enough, poor imaging, and a LOT of horn coloration. I was about to walk away, when the dealer suggested Graaf OTL. The sound was MUCH more acceptable - more neutral, detailed, and with better rhythm. I have also heard the Duo's with my old Cary 805-AE SET's. Very nice, but I preferred the sound of the Graafs.
I have not heard sound from the Avantgardes which have really impressed me, but that might be because they need better amplification than what I have heard them with. Best of luck with your quest.