The uPC1253 was the same device as the 2252. The part was developed at dbx in the early 1980s. At that time dbx licensed their noise reduction systems to many consumer audio manufacturers, primarily for cassette decks and reel-to-reel tape machines. (Teac/Tascam were among them, but for a time there were many others.) Licensees were permitted to purchase the uPC1253 part directly from the manufacturer (NEC) since they paid royalties to dbx. Non licensees purchased the 2252 device from dbx. These devices were tested and marked at dbx (and, later, at THAT). Shortly after we started THAT Corporation sales of the part became exclusive to us.
