I bought a Bose Acoustimass 6 speaker system in US (110V) and planning to use it in India (220V). What would be the best converter spec required for my Bose to give the full performance? I also have an Onkyo SR506 receiver, bought from the US.
Any converter will not alter the performance of you system; the only risk you may take by using a bad converter is to fry your unit because the voltage in india is higher. RCA makes some good ones. make sure you use surge protection. it is very important. Not all the converters have surge protection. some of them are just plug adapters. read the box carefully.
Getting one from India is probably better as for warranty. An auto voltage regulator step down transformer which works like the surge protection are good ones, it will adjust proper voltage depending on much the voltage varies.
But if you think the voltage is stable, no regular brownout/blackout and away from construction, manufacturing facilities or your house does not have big or many generators that kick in at the same time, then surge protection is only good for lightning’s/storms.
You might want to consider UPS at this point because some have dual input and output of 220V~240V and 110V~220V which better protect you system.