[freo]

Does anyone know if there is a way of finding out if a power amp is running in 50 or 60 hertz there is no plate on the back with this information, it was built in the states and runs 220v. I live in Australia which is 240v 60 hertz
Thanking you all in advance
Regards Roger

[Occam]

A power transformer (assuming the amp uses a power transformer) designed for 50hz operation has no problem operating at full power at 60hz. The opposite is not true, a transformer designed for 60hz might not be able to operate at 50hz and deliver its designed power. So your 60hz power in Australia shouldn't present a problem.
What might be of concern is the voltage of your transformer, nominally designed for 220vac operating 240vac, which would give voltages a bit less than 10% higher on its secondaries than the design calls for, which might (or might not) be problematic.

[JoshK]

Things run *on* what comes out of your wall.  So if Oz has 60hz, that is what you are using.  We have 60hz here in the US too, so likely it was built for 60hz in mind.  Typically it shouldn't make a huge difference unless your caps/transformers were really marginal.  It will change the dominant ripple voltage to 100hz instead of 120hz to run 60hz equipment on 50hz.  That in and of itself isn't a big deal.