Most converters and transformers change voltage but do not change cycles in their conversion process. Therefore it is important to know whether the electric device will operate the same, even though the AC current being supplied is on a different cycle. As a rule of thumb, the appliances that are affected by cycle differences are those with motors such as turntables and clocks. They will run faster or slower than they should, depending upon the cycle difference. As with any rule of thumb, however, there are many exceptions. The only way to be sure is to consult the appliance's technical documentation or to contact the manufacturer.