Need help ...

I would sale the mac and get a pass preamp that would match up better and sound better with your pass amp.Any mac product that I have ever had was noisy and slow and just didn't sound very good to me.The oppo is not bad but I would look for a better dac such as ps audio ds or junior,I have both and love them.You could use the oppo as the transport and use the digital coax out to the dac.

I would'nt worry too much about cables as long as you are using decent ones.

Kenny.

IMO the source is the biggest influence in sound in a system although others do not agree with me.  The Mac has a sound that is usually very musical with sweet mid-range sound.  That is more of a preference.  The suggestion to use the Pass preamp will change the sound from the Mac preamp so this is a preference thing again.

Happy Listening.

You have a good system. Your best bet for improvements are room treatments and cables.

thank you very much to every one give me suggestions. ....now i think i should sell MC C50 and looking Pass labs xp30 0r xp20. these speaker cable i’m using MIT cables and XLR shunyata connector and i’m thinking to placing some panel to reflex the sound it will help better sound right !

The Oppo is fine choice for background music or movies, nothing more.  With it as your source the rest of your equipment is way overkill.