AMPEX ATR-800, along with the ATR-700, was made for Ampex by Tascam. This engendered anger and resentment by USA customers and led to Ampex's rapid decline in the market. They were excellent nonetheless, and compared with the Studer B67. Far better than the Otari MX-5050 in my experience.
1934: AEG K2 Magnetophon, the first modern tape recorder. Tapes ran at 39 ips, and were an Fe3O4, oxide, not the Fe2O3 type which is the normal bias tape of today. One day, a K2 that was producing recordings of extraordinary quality was sent “for repair.” Service techs found its DC bias amplifier was oscillating, making an additional bias. The tape's magnetization became directly proportional to the instantaneous audio signal. AC bias is at the heart of every magnetic recorder since.