I don't believe the Arcam has pre in, only pre out. I also don't believe you could go through stereo direct. I believe that input is to run a cd player direct to the amp section without processing the signal. Others who are more familiar with the Arcam can hopefully chime in. If you want to keep the Arcam, I think you've got two options:
1. Add an amp for your front two channels and use the Arcam for everything else (as you've been doing); or
2. Add a pre amp and amp (or integrated) and use the Arcam for Home Theater processing and surround amplification.
1. Add an amp for your front two channels and use the Arcam for everything else (as you've been doing); or
2. Add a pre amp and amp (or integrated) and use the Arcam for Home Theater processing and surround amplification.