SC-805 Plug and Play with SC-901?

Hi people, my C70 had the SC-805 radio and the 4x60Watt amplifier installed as standard. The loudspeakers have Dynaudio stickers. After I have a 4x100Watt amplifier and a SC-901 installed, my sound is really not intoxicating and I have to make extreme settings on the equalizer so that it can sound pretty good. Can it be that I didn’t notice anything and now what’s wrong with the setup? And the SC-901 isn’t, is it? I know the original Dolby system from the C70, that was super.