using 230Volts Hifi components in the Usa

                          Be certain your gear can function properly, at 60 Hz.

                                   Especially: the Cassette Deck’s motor.

http://www.50hz60hz.com/what-happens-if-50hz-motor-is-driven-at-60hz.html

                                      Inverters/converters are available.

                                              Examples:

            https://www.kccscientific.com/all-products-from-kcc-scientific/

 They (good ones, anyway) can get salty, depending on your device's current draw/consumption.

       Some cassette deck motors run on DC, after power supply conversion and would not be affected.  Others: AC/synchronous.

                                           Best to check!