isolation transformer - high voltage.

[atmars]

I have about 124v at the wall outlet in my area. I have a 1:1 isolation transformer between a amplifier and the wall. Even thought the transformer is 1:1 the voltage it is putting out is closer to 130. Any ideas why this is the case? The transformer is rated at 115v (see picture). Could that be the reason? I thought the the idea of 1:1 is that the windings are identical on both sides, so what goes in one side comes out the same one the other. If the windings are not identical for some reason, could I reverse the input side and output side to reverse the voltage imbalance (high at the wall, lower at the amp).

I need the transformer for safety, but it is making my already high outlet voltage even higher.

Thanks.

[Steve Conner]

The secondary will have more turns to compensate for losses, so that it's still 1:1 at its full rated load. Therefore, the voltage will be too high at light loading. Yes, you can reverse it.

[atmars]

Thanks,

I am using this isolation transformer to run a transformerless amp from the fifties. The schematic and the back of the chassis say the amp wants to see 117v, so I thought 130v was way high. I don't know how much the amp loads the transformer, but the voltages are higher with transformer than they are with power straight out of the socket. I'll flip it around and see how that goes.

[atmars]

Reversing inputs and outputs results in nearly 117v on the money. Thanks for the help.