Question on amp's HERTZ (frequency) reqmt.

[Steve K]

Hello,

I'm in Tokyo, where the mains power specs are 100volts at 50Hz. If I bought an used power amp from the US (120volts at 60Hz), other than needing a voltage UP transformer (100v to 120v), would I also need a frequency converter, too? Thanks for your help in advance!

Steve K

[timc]

Hi.

That would depend on the equipment you buy. Some have Hz detectors and some don't.

-Tim

[Steve K]

Thanks, Tim, for your fast reply.
Okay, I'm thinking of an JBL UREI 6260. Does it have this detector?

Steve K

[grumpy]

If I read the manual correctly, the US/Canada units were wired for 120V/60Hz only;
units intended for other regions were marked with their AC input requirements.

For this type of power supply (transformer, diode bridge, caps), the transformer
and some other power supply parts are often not the same for 50Hz operation.
Maybe one of the folks here that has experience working on this series of amp
can tell you if there are alternate windings on the transformer than might help.
-grumpy

[timc]

Thanks, Tim, for your fast reply.
Okay, I'm thinking of an JBL UREI 6260. Does it have this detector?

Steve K

I dont know about that product, And Steve K is correct in his statement. However there might be even another thing to consider. Mark Levinson uses multitap transformers in their power amplifiers. It is just a matter of changing a few connection points innside it for the various voltage settings. On their Preamps and DAC's however they have a Hz "sniffer" wich prevents the unit from turning on, if the Hz is wrong. If the Urei dont have this, you could simply get a Voltagetransformer and maybe change a few parts innside it to get it working.

Good luck

-Tim

[Hoerninger]

When a 60 Hz transformer is used with 50 Hz then there is too little iron in the transformer. The power handling capacity will be reduced.
This problem can not be solved by the number of windings.
(On the other hand transformers in switching power supplies can be comparable much smaller.)

But I admit I have no experience with these adapter problems.
____________
Peter

[Allanvh5150]

I have not had problems at all with 50hz gear running at 60hz or vice versa. As long as the equipment has a standard transformer supply, there wont be a problem. I have even used Carver amplifiers on different supplies and have not had problems with it.

[Steve K]

Thank you all for your replies!
I'll get a 100V->120V transformer to run the amp when I get it.

Steve K

[Baron030]

Hi Steve K
You can use a low voltage step down transformer boost the voltage up.
In the schematic below, the secondary windings are wired in series to either boost or buck the incoming voltage depending on the phase of the secondary windings. The transformer's output current rating should be higher then the amplifier’s load, otherwise you will burn up the step down transformer. And I would also recommend wiring in a fuse between the wall outlet and the transformer, just in case of a short. While this may not give as big a voltage boost as what you are looking for, try looking into a 12.6 Volt filament transformer. They come in sizes that have fair large current capacities and they are relatively inexpensive. So, a filament transformer just might do the trick, without busting your bank account.

Baron030