I just picked up an Access HD 1050 and this is my complaint with it. The line level of the audio output is about half what it should be. All the channels are pretty much the same. Nothing reaches above half meter on the amp, when they should be full. The RF audio is monaural and muddy. The RCA output has great dynamic range and fantastic separation, but both RF and RCA are the same low volume, despite the converter's independent volume turned up to it's maximum (which, oddly, is 63). I find this very irritating because the amount the TV or amplifier volume has to be cranked up makes a lot of line level hiss and distortion much more prevalent.
I thought this converter was defective but if people are having the same issue with other brands, perhaps it related to the chip set or something inherent in the current broadcasts?