using 230Volts Hifi components in the Usa

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

                                   Especially: the Cassette Deck’s motor.

Are you certain the motor is AC? I'd expect it to be more likely DC.

You can buy a  used US cassette deck mucho cheaper than a transformer.

The service drop into US homes is typ. 220vac single phase; 2 - 110~120 vac and a common ground from the pole. There’s the ’local’ ground, a bare copper line running to an earth ground nearby. That grounds the metal cabinet, and is a ’back-up’ if sh*t gos’ south.

The box inside has a ’left’ and ’right’ 110 leg, single phase, ’hot’.

Otherwise, some of the shop tools I own are running on magic.....

You can run your own line, but a step-up will be cheaper....

If you've only the single hot leg...

You ought to rewire.  Your wiring is likely 'knob and tube' if your home hasn't burnt down....yet....

Just sayin'

...and less exciting if you make a mistake... ;)

I have a European spec (England) high end integrated amp and bought it because conversion rates at the time were great.

I got my power transformer from this company and I was so impressed how incredibly built it was and how well it works.

They're kinda big, but just an awesome product.

https://acupwr.com/

Years back I was relocated to the Netherlands and had my ARC LS15 tube pre amp converted to 220 V  When I returned to the US I called ARC to convert the LS15 back to 120V  ARC recommended that I buy a step up transformer as the LS15 tube pre amp would actually sound better I've been using it with a good step up transformer for years