It has to do with the DA/AD converters on the MPC. This will be tough to replicate in Reason. The waves stuff is so successful because they can write there own algorithms. In fact the SSL plugins will actually phase cancel a real SSL and that pretty amazing.
Are you on Windows XP? Or Vista/7 Fruity will usually have its own volume control and if it is XP it will haev a wave volume that you can also turn up
see here
http://ridgeviewinitiative.com/DrumMixer/Images/WinVolCtrlInPB.PNG
In osx you can right click on a group of files and say edit id3 tags, I also think itunes can do this. Or check out http://www.feedface.com/software/tritag.html