anyway, that's the device you have to find, just a little bit more powerful.
About que sound quality, If the converter is transformer-based, there is no degradation or noise in the output line to the deck. There will be no change.
If the converter is a switching device (could it be??) then the deck power supply has some kind of filtering and stabilizing circuits. It will depend on the quality of those.
It has more to do with the frecuency of the line. in europe we use 50 hz, I think americans have 60 hz. The power suppply may be designed to filter better 60 hz, but I think it's gonna make a small difference in sound quality, anyway.