QUAD FM4 - bought in Europe, can I use it un US?

I moved from the UK to NA 25 years ago, with my QUAD FM4/44/405 system. Yes, the FM4 will work fine here. However, the FM de-emphasis in NA is different to that in Europe, 75µS in NA versus 50µS for most of the world. Consequently a European tuner will sound slightly bass heavy if used in NA. The fix is simple, a single capacitor addition in the de-emphasis circuit. I had mine done by QUAD before I left the UK. I am sure QS&D in the States can do the job for you at nominal expense. Re voltage conversions, my FM4 is dual voltage, so no problem here. If yours is not, use a $25 step-up transformer or have QS&D do the conversion for you. I am not familiar with the newer FM4 tuners, maybe it is a simple jumper change you can do yourself to go from 240V to 110V

Correct, nothing else needs changing.