Use of a 110 VAC to 230 VAC Step-up Transformer for CD player.

50Hz versus 60Hz is only a problem with AC motors and stuff like Krell and Martin Logan equipment. This two manufacturers, I am sure there are others, install a frequency sensing chip in the power supply and will not allow the equipment to operate if you have the right voltage but wrong frequency, This is not true with older Krell gear. For example, I used my Krell KSA-250 in Europe and the States without issue, all I had to do was change some dip switches on the power supply to go from one voltage/frequency to the other.

AC synchronous motors, for example on TT, will not run at the right speed  if operated on the wrong frequency.

Ran 220v tube preamp using off the shelf converter with no discernable ill effects.
Get the 500w version.
https://www.amazon.com/dp/B004MPR3XQ/ref=asc_df_B004MPR3WW4794928/?tag=hyprod-20&creative=394997...

Make sure you know the wattage of the 220V equipment, and get a higher wattage rated step-up transformer for it. For example, if the device is using 50W, get a 100W step up transformer.

I have a component that runs off of 220V, and I used a 50W step-up transformer with it. Turns out, the component was pulling more than I thought it would, and the plastic case was starting to melt!

Also, give your step-up transformer "room to breathe". One of the reasons the one I mentioned above overheated was because it was directly plugged into a Monster power center, and physically touching said power center, not allowing enough air to circulate to cool the transformer.

Now, I'm using a 100W step-up unit, and one of those short extention cords that you often use on a power strip to prevent a 'wall wart' from hogging all the sockets.

Eventually, I'm just going to replace the internal transformer to a 110V version.

@joeylawn36111 I also want to just swap 220v transformer in a Marantz CD63 (Philips CD100 rebranded). Cannot find 16V 28V dual secondary transformer though... Any tips on where to get one?