One effective,easy, and inexpensive solution for the different level issue between phono and CD is to use RCA phono attenuator plugs in line with the higher level CD IC to lower that level more to the level of the phono. I've used Harrison Labs 12 and 3db attenuators both separately and together for a similar issue with excellent results.
http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0
http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0