Have any of you guys tried the headphone output of the Oppo? I know Dan does not alter the headphone out in any way. In my unit with higher impedance headphones (AKG K-601; 120 ohms), I hear a definite low level hiss. Also, as the player initializes for CD/ SACD playback I can hear low level crackling through the headphones. The hiss is constant and does not change with volume. With lower impedance headphones (Audio Technica ATH-AD900x) the hiss and crackling are unbearable. Many have alluded to the headphone outs of the Oppo being marginal at best, but I'm not sure if there is a problem with my headphone out. I guess my Oppo warranty is voided since I've had the unit modded. That being said, the sound via speakers is awesome!