In this usb fm transmitter circuit the pre-emphasis of the input is missing. Radios in Europe have a built-in de-emphasis network of 50 μs (75 μs in the US). The sound from the radio will therefore ...

The circuit required to tie into the USB lines is made up of just a few basic components, and [Ray] provides a reference schematic and ... pins and all 6 Analog Input pins are logged.