I'm not sure what a "KI" is, but a stock CD63SE has a built in "volume control" (accessible via remote only). If your unit still has this, you should be okay as long as the input impedance of the amp is over about 20k. The only problem with this is that after the CD63SE is turned off, if I'm not mistaken, it comes back on at full volume. Also, it may start playing any CD that's in it. This might not be healthy for the speakers! Also, the SE's attenuater isn't too great sounding below about 50%. The manual states that the output impedance of a stock SE is 200 ohms, with a full scale output of 2 V RMS.
Resistor value for interconnect
My system consist of Audiolab 8000A ( as pre amp) , Power Amp (pass labs Aleph 3) and CD player ( Marantz CD63se KI ). When the volume turned to 11oclock position the sound level is not what I would call loud, But when fed directly from the CD player It sound more dynamics and goes louder. I'm afraid that it might cause damage to the speakers or amp if running this configuration? As I recall reading stereophile the reviewer Muse Kastanovich did solder resistor to the interconnect when he review the power amp, when fed directly from the CD source, but he didn't mention the value of the resistor? I need help ( resistor value) from owners who have try this or any professional help is greatly appreciated. As I'm thinking of bypass the pre-amp and directly fed the CD player to power amp. Thanks