Hi, I am usually in the Marantz/Pioneer forums, but have AKer Warrens C2 here. There is not much out there on this model so just wanted to put this up for informational purposes in case it can help some one out. Warren wanted to refresh the power supply caps and maybe do something with the op amps. The phono was intermittent if he wiggled the cable it would go on and off. In this pic you can see where the phono input to the board has cracked in a circle from normal daily insert and removal of cables: What we did was reflow and refresh all of the input legs to the board to make sure they are sturdy. I also found 2 other cold/bad/ joints one on the pre board and one on the filter board: here are all the inputs across the back: Warren will be using this mostly for vinyl so here is the original op amp: Here is a view of the main board lay out, very nice clean and orderly!