You have a lot more to worry about other than voltage.
It is generally a bad idea to try and use AV gear across different jurisdictions.
The voltage is the easy part.
You would need a transformer, to convert from 240 volts UK, 220/230 the rest of Europe to US 110 volts.
You need a transformer that is at least 25 to 30% above the TVs power rating in watts and the VA rating, since the receiver is an inductive load.
The bigger issue is the TV system. UK and Japan use the NTSC system. The UK and a lot of European countries use PAL. France and some others use SECAM.
HDMI does not convert between the three.
So that will be your biggest mess.
The next is FM radio as the US has 75 msec pre emphasis/de emphasis, and Europe has 50 msec.
My advice is to sell you current AV gear, before you leave if you are staying a long time and store it here if it is a short time.
You need to buy a receiver, TV and other AV gear for the country you are in.
Also players are region sensitive.
I have a son in the UK for two years. He is just over half way through his assignment. He did not ship any of his AV gear to the UK, it is not worth it and you will regret it if you try.