Equalizer

I'm going to buy a 4ch amp should i add a eq after that?

I want precise tone shaping

Then instead of buying another item to go into the signal chain (and add the possibility of noise and extra wire), consider a better cd player that will allow you to do this. My recommendation is the Eclipse CD5000 and add the calibrated pink noise microphone and memory stick. Blast the pink noise through the system using the built in tone generator, snap a digital tonal response picture onto the stick, upload into your computer and manipulate away to your hearts content. No offence to your cd player, the Eclipse, out of the box, will give you a big big big difference in tonal response without touching a thing.