I just purchasaed a used lexicon cp preamp from years back. It allows me to set the input gain for various devices. It reccomends setting cd players to -3db, video disc players to +6, and multi disc players to +6. I currently only have a marantz 3002 dvd player hooked up for cds and dvds. How do I know what to set the gain at? Is a dvd player the same as a video disc player?