Just bought a Marantz PM6006, and it it disappointing

My vintage NAD7020 has been acting up, so I decided to get a Marantz PM6006 on sale.  Figured if I decide to upgrade later it could become part of the AV system.   I had no problems hooking up my Linn Axis turntable and ELAC Debut 6.2s.  But when I started playing music, I noticed the music was muddy and high pitched.  I tested on some jazz (Don Shirley “Tonal Expressions”), classical (Villa-Lobos “Bachianas Brasileiras, Nos. 4, 7”), Rock (The Grateful Dead “The Grateful Dead”) and P-Funk (Funkadelic “One Nation Under A Groove”).  The only song that sounded as good as I wanted was Laurie Anderson’s “O, Superman”, with its heavy synthesizer work.  Throughout each selection I noticed pronounced sibilance, and violin and harmonica were actually painful to listen to. Needless to say, I am extremely disappointed.

Granted, I am used to vintage (used) electronics, and I very much prefer the warm sound of the NAD.  So, is my ear just attuned to warmer sounds?  Or does the Marantz PM6006 need a burn-In period?