Arcam AV-700 volume control and by-pass mode

I've been researching the type of volume control used in my AVP-700. I'm also tying to determine how true/pure (not sure exactly how to word this) the direct by-pass modes are. Unfortunately I'm having little success.

I'm trying to determine if it would be advantageous to upgrade the pre-amp section of my rig, or if my money would be better spent elsewhere.

Equipment: Naim CD5i, Arcam AVP-700, Odyssey Stratos Extreme, Usher-6381, Chord Cobra II and II ic's, and Monster M1.4 speaker cables.

Any assistance or links most appreciated.
No need to upgrade, i use mine for anolog pass thru and it sounds great.Arcam had this in mind when they released it. the volume control was given equal attention. You can find product details on Auduiproducts International as well as Arcams own website. This company pushes the envelope with every product. they trully love what they do how about that a company who has the same kind of enthusiasim as we do! And no i dont work for them.Hope this helps