Fixing a weak Digital Cable audio signal??

We recently signed up for Time Warner Digital Cable, and the audio output is much weaker than the signals from my CD, DVD, FM sources. I have a whole house system (Crestron) and when I switch from the digital music channels to another source the change in volume will blow away anyone who is listening anywhere in the house(or worse, my entire neighborhood from my many outdoor speakers. The Cable has a volume attentuator, but I have it turned all the way up. Has anyone seen/solved this problem (besides a much higher end preamp)? I need something similar to the old phono pre-amps.