Do you really need a step-up transformer?

Question

i am going to bring some 240vdevices into the states which, i believe, uses 120v.

Do i really need to transform the electricity from 120v to 240v ?

I know that on the other hand, 120v devices which are not 240v ready should have a step down transformer to prevent a blown fuse or damage to device.

But in this case, is it true to say that if a 240v device would at worse be less efficient or underperform when supplied with a 120v electricity. Or would it damage the device?

Answer 1

it should not damage the device
however things such as cd players, cassette players will draw 2 times its normal amperage and will run a bit faster as the usa uses 60 cycle and europe uses 50 cycle

Answer 2

as most devices have a voltage regulator in them and 120 is well below the 220 required parameters of the regulator, they will not work.