Peng has given you good advice.
The power draw spec. of that unit is not in the spec sheet of that unit.
Generally your idea is a bad plan, and I agree not worth the investment.
Also you did not state the country this is designed for. Since it is 220 volt, I suspect it may be from Asia. Some Asian countries are two phase 220 and not single phase like Europe.
The next issue that the FM Eq constant varies from country to country.
I strongly support the idea of buying a new unit, given the cost of a decent safe reliable unit to power it from 220 volts.