Digital filters - Sony SCD 333ES


I bought a used 333ES without a manual. It has 4 digital filters that make subtle differences in the sound. I'd like to read a detailed explanation of what each of the filters is doing. Can anyone suggest where I might get such information? Thanks!!
jgold0016
Yes, the digital filters work only with CD. I basically use "No Filter" and "Filter 2", the latter giving kind of an LP feel to the sound. It's a nice feature on a very interesting, competent, and underrated player.
Jgold0016, I had the Manual, & the 1999 Stereophile review in my briefcase the day of your post. I will fax both tommorow to your fax number listed above.