Hum is caused by earth loops not transformers, unless your cables are not properly shielded. Otherwise, you have no worries.
Some manufacturers have multiple voltage support in their devices. If that is the case, you are in luck, otherwise....get a transformer and do NOT skimp on it unless you want a fire in your house, get the best (US made, not Chinese). Get one at least 1.5 times your maximum need.
https://acupwr.com/pages/voltage-transformers-converters
Some manufacturers have multiple voltage support in their devices. If that is the case, you are in luck, otherwise....get a transformer and do NOT skimp on it unless you want a fire in your house, get the best (US made, not Chinese). Get one at least 1.5 times your maximum need.
https://acupwr.com/pages/voltage-transformers-converters