Quickly ordered and received 6 180 TDK cassette, but with use, the cassette 2 6 are disposable: A jamming his (Burr 50Hz) even very embarrassing and indelible after several recordings is superimposed on the sound of the Recorded TV show ... The quality of the products imported from Germany has fallen. The other 4 cassettes function well (fortunately). We just need to order 33% more, to have the desired number of cassettes functioning normally.