An update to an issue that was discussed many pages ago. I was using the Oppo 103 as a preamp - connected directly to the TV via HDMI and via analog cables to an Outlaw amp, with digital cable box running into the Oppo. I could hear constant hissing and loud pops when I changed channels, etc. Oppo suggested it was the amp and that I purchase some attenuators, which is not a great solution. I unplugged everything and started plugging them back in one at a time to try and isolate the issue. I plugged the Oppo into an outlet far away. I plugged the Oppo into my second system, running it though a good Denon receiver. No problem when plugged into the Denon. Problem persisted with everything else. So I broke down and purchased an Emotiva processor/receiver (UMC -200). All pops and hisses are gone. This is clearly an issue with the Oppo. And I do not think it is an HDMI handshake issue, because the hisses only occur when the Oppo is run through the amp via analog cables. It does not exist when I was using the tv's speakers, leaving the amp turned off. I know there are people like me who really wanted a pared down system because all I use this one for is movies and television and the 103 looked like a great solution as a player that can also be a preamp. Not there yet.
Check the Hum & Hiss FAQ in the Audio Theory forum here. Your problem with the Analog connection direct to the amps may be due to an external source. The usual culprit for hiss is RF interference emanating from room lighting dimmer switches -- perhaps in an adjacent room. The relative gains involved may explain why the hiss (penetrating interference) is only showing on the Analog connection direct to the amp. The FAQ may have other useful suggestions for you as well -- e.g., how to try to isolate this.