Abbreviation for Digital Tape Recording System. DTRS generally refers to what we call the MDM (Great, an abbreviation that refers to another abbreviation), or Modular Digital Multitrack. For the most part both of these terms are used to describe ADAT‘s and DA Series digital tape recorders (as well as similar units that have been distributed by the likes of Fostex, Panasonic, Sony, Yamaha, Studer, etc.). They are both digital tape recording systems and are both modular digital multitracks in that multiple units can be easily combined to build a larger system with more tracks.