a little searching on the net resulted in the following comments... and I agree with them also
An autotransformer is a tapped winding transformer that changes the voltage available locally to the voltage required by a particular load. Thus, a load may operate anywhere around the world, as long as a transformer is available to convert the local voltage to the voltage it requires.
Transformers will change the 240v/50Hz to 120v/50Hz.
I have not seen any laptops that do not accept worldwide power (100-240v/50-60Hz). Most desktops computers and many consumer electronics such as TVs, also have universal power supplies. AS i SAID BEFORE you need to check to be sure. (as your example your cd changer)
You CAN run some electric motors at the wrong frequency. They will run at different speed, and may die prematurely. Frequency conversion is not cheap!
If you have any lamps, they are the easiest to use - just change the bulbs.
You will need plug adapters for the transformers and lamps, to be able to plug them into different outlets.
Also think about your phones if you havent...... diffrent ringing frequency and operating/ringing voltages. And with cordless phone you have three problems that I can think of. First is the electrical powering issue with a converter. Second is the issue of DTMF/wiring/ringing frequency and voltage with a US style box. The third, however, concerns the RF frequency of the cordless phone. Depending on its age, it could be any of 900MHz, 2.4GHz, or 5.something GHz. These are US license free bands. "Is this frequency band legal for non-licensed use in the the country you are moving to?"
I know I haven't really answered your question and I am probably just rambeling on and on but it is getting late here..... I guess if it is not rated for 50 Hz Id plug it in with caution and expect it may get damaged. If you would need to buy one any way whats the loss? Unless you'd plan on selling it before you leave.