In general....yes. The RS-1994 has the built-in codes to operate Denon, Sony and Mitsu equipment. If your equipment is not too old, these codes should work fine. You may however loose some functionality, as the buttons on your original remotes are not always all mapped to buttons on the RS-1994. Often you can still program these under buttons of your choice using "advanced codes", which is one if the features that makes the RS-1994 so cool. Check out
www.hifi-remote.com to see if advanced codes are available for your equipment (probably are). Also read the RS-1994 manual on this site to help you understand it.