Anyone use 100v or 220v gear with a transformer?

300w is going to be too small. It will 'work', but you'll probably find the amp sounding constrained. Any transformer with a 1KVA rating should do.

Regards
Paul

+++ If the maximum draw of the amplifier is 195 watts, how will providing 1000 watts be more beneficial than providing 500 watts (or more than double the maximum draw of the appliance)? +++

Easy, transformers are reactive by nature and distortion/reactance goes up the closer a trans get to its rated output. The bigger the trans the better. A 1 to 5 ratio will yield about the best performance per buck.

If you were running a 200watt heater or refrigerator I'd say use a 300watt trans. A 300watt (or 500watt) trans will not let your amp do its best. .

Regards
Paul

+++ a transformer will absolutely diminish performance +++

That is patently untrue. Given the correct isolation transformer, it will dramatically improve your sound, especially if you live in apartment complex where the mains are very dirty. Isolation transformers can drop noise floor by 6 to 12 db.

Folks like BPT don't have thriving business because their products detract from sound.

I guess you are the lucky one – enjoy your iPod.

Regards
Pauly