I have not heard the Levinson 39 but I did compare the CD50 and CD55 extensively with each other. I also compared these against a Meridan 506.24, a Thule balanced CD (150 ?)and separates consisting of a Rotel tranport and a Sonic Frontiers tube DAC. The Resolutions easily beat the competion with the Thule coming in the closest. I ultimately preferred the CD55 over the CD50 - a more refined sound and slightly better soundstage (it has upsampling, the CD50 does not). I kept the CD55. The CD50 and CD55 are unbeatable for the price.
