Hello, My RX-505 plays fine but can´t flip. It´s probably a mechanical issue, a worn gear wheel perhaps.
The sound is quite amazing, it´s much better than digital IME: my 40+ years old c-cassettes outperform modern 24 bits digital in dynamics (musicality) but have more distortion although not intrusively. Digital is still dull after 30 years, it is progressing in tremendous velocity though.
Glad to meet another Nakamichi UDAR lover.