Llippman, I'll just add the following thoughts to the excellent inputs and analyses you've been provided with above:
1)Before deciding how to proceed, I would suggest that if you don't already have one you obtain a good quality multimeter and measure your line voltage, preferably during the day and during the evening, on both a weekday and a weekend. The further removed it is from 120 volts (in either direction), at the times during which you generally listen, the greater the likelihood that a regenerator will be beneficial, IMO. The reason being that in most cases components sold in the USA and other countries where 120 volts is standard are presumably designed to sound their best at that voltage.
2)Estimate and take into consideration the length of the house wiring between the outlet(s) which power the system and the breaker panel. For example, if that length is 50 feet, and the breaker is rated at 20 amps, chances are the wiring is 12 gauge, and an increase in power draw of say 1500 watts that may briefly occur on dynamic peaks in the music would then result in a corresponding brief voltage drop of 2 volts, due to losses in the wiring. If that length is 100 feet, a 4 volt drop would briefly occur on that dynamic peak. The greater that fluctuation in voltage, the greater the likelihood that a regenerator would be helpful.
3)Keep in mind also that if the system is powered via a single 20 amp breaker, the maximum amount of power that is available from the outlet(s) is/are approximately 20 amps x 120 volts = 2400 watts. Although power demands above that value resulting from occasional very brief dynamic peaks can presumably be supported without the breaker tripping.
Good luck. Regards,
-- Al