In exchange for my faulty silver PVR, I got the newer Explorer 8642. The sound level is drastically lower than the previous PVR. I exchanged it again, and got the same results. I have to boost the sound on my TV quite a bit more than with the silver PVR.
Is this normal or is there a setting I did not find yet ?
You might want to try the steps outlined here to see if it resolves your problem. The step 6 in particular might be what's causing the lower volume compared to your previous digital box as I was able to resolve the same problem with mine.