I am driving the Aleph 2s with an 860x. I had to get inside and change the output voltage to the max to get the level I wanted. At the max setting the 860 won't drive my speakers as loud as the Adcom GFP 750 in passive mode! I also found that the sound was better with the 860 output voltage set to max as well. Carl seems so passionate about the CD50, that it's making me want to get one to compare to the sound of the Wadia. I would consider driving the Aleph 2s balanced as important as well.