4Safety Information (continued)CQ-C7403U/C7303U/C7203U/C7103UCautionTHIS PRODUCT IS A CLASS I LASER PRODUCT.USE OF CONTROLS OR ADJUSTMENTS OR PERFORMANCEOF PROCEDURES OTHER THAN THOSE SPECIFIED HEREINMAY RESULT IN HAZARDOUS RADIATION EXPOSURE.DO NOT OPEN COVERS AND DO NOT REPAIR BY YOURSELF.REFER SERVICING TO QUALIFIED PERSONNEL.The following applies only in the U.S.A.Part 15 of the FCC RulesFCC Warning:Any unauthorized changes or modifications to thisequipment would void the user's authority to operatethis device.This operating instruction manual is for 4 models CQ-C7403U, CQ-C7303U, CQ-C7203U and CQ-C7103U.The difference among these models’ are mentioned below.All screens and main body illustrations in this book represent CQ-C7403U unless otherwise specified.Panasonic welcomes you to our constantly growing family of electronic products owners.We endeavor to give you the advantages of precise electronic and mechanical engineering, manufactured with carefullyselected components, and assembled by people who are proud of the reputation their work has built for our company. Weknow this product will bring you many hours of enjoyment, and after you discover the quality, value and reliability we havebuilt into it, you too will be proud to be a member of our family.SQ3SQ3SQ7SQ7SQ (a page 19)NoNoYesYesCustomize function (a page 31)NoNoYesYesSRS WOW (a page 18)2 V (200 Ω)5 V (60 Ω)2.5 V (200 Ω)5 V (60 Ω)Preout2 V (200 Ω)5 V (60 Ω)2.5 V (200 Ω)5 V (60 Ω)Subwoofer-outputCQ-C7103UCQ-C7203UCQ-C7303UCQ-C7403UModelsFeaturesBefore Reading These InstructionsDifferences Among 4 ModelsThe instruction manual consists of 2 books. One is “Operating Instructions” describing the operations of the mainunit. The other is “System Upgrade Guidebook” describing the optional devices such as CD changer.