CAN I RUN 50HZ AMP ON 60HZ?

There are absolutely no problems at all running something designed for 50Hz on 60Hz, unless it has an AC syncronous motor in it, which will then run a little faster.

A power supply designed for 50Hz actually runs better on 60Hz. There is less saturation in the power transformer and the filter caps will be more effective.

The problem exists going the other way!!

There's a problem with overheating using 60 hz power supples on 50 hz power since the effect would be an overvoltage, but not the other way around. Also, running at 60 hz increases the ability of the transformer to accommodate a larger voltage swing. The transformer is effectively uprated - runs cooler and has a higher voltage headroom to maintain VA rating.

As far as ripple, voltage change is decreased since energy delivery to the caps is faster. Running at a higher frequency should not be a problem.

You can run, 50hz transformers on 60hz. If it effects the the DC power supply I can't say. It would seem to me that at 60hz there would be more rectified full wave ripples for a given time line. Filtered Dc output should be smoother, cleaner. Maybe an EE can shed some light on the subject.
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I have not had any problems in the US running a 220 Watt per channel power amp and preamp (designed for 50 Hz 220 V)with a step up transformer.

The current demand will be roughly double what it would normally use at 230 V, which may be higher than is recommended for your home. Check your amperage specifications for your house breaker. Also check what the input power requirements are for the power amp (user manual - how many watts does it consume). Power amps are like toasters or hair driers - they consume oodles of power, so you need to get an appropriately rated transformer and make sure you ground things properly (chassis) to prevent danger of electrocution in the event of malfunction.

Although it worked for me, I would not recommend this approach for saftey reasons. BTW, I have since changed my power amp and got rid of my step up transformer.

I once brought over my Harmon-Kardon equipment from the US (60 Hz) to Finland (50 Hz) and had no problems once I used a step down transformer. The difference between the frequencies is most important for equipment with synchronous motors, such as in some turntables, etc. But you should obviously check with the manufacturer for more subtle issues.

From a safety point of view (damage to the amp or other equipment) the difference between 50 Hz and 60 Hz is not an issue in this situation. Whether or not they will provide the same level of audio quality is another issue. Assuming a properly designed power supply (which is turning the AC into DC regardless of Hz) I wouldn't think that'd be a problem either.