What to expect if I import an amp and preamp from a Japan seller via US eBay

@2psyop Thanks.  I hadn't thought of that.  Where is the signup for the first rodeo?

A quick google search will get you to the Official U.S. Customs lists for Japan. I didn't look for amplifiers, I researched turn tables. It turns out that turntables/record players (and associated parts, like tone arms--- I bought a tonearm from Japan as well) are exempt from customs duties when imported from Japan. The seller I used in Japan understood this, and the customs declaration stated "Record Player". I had no problems ($'s or delay) at US customs (and the TT came in by air, but still seemed to take a couple days to transit the system). I do remember seeing other components listed, but once again, I was looking just at TT's. I am not computer savvy, but found what I needed in a jiffy, but you will have to go through a substantial list (I skipped over "Heavy Mining Equipment" and "Electrical 3 Phase Switching Apparatus". Yes you will need to step down the 120V to 100V, but both are 60 cycle. Don't skimp on the transformer. My TT performed very well with a transformer, held speed, no noise, etc. All in all the TT and the arm were painless, and a good value. Good luck

I would not send more than $100 or so out of the country.  You'll never get your money back no matter what unless _maybe_ if you use a CC that will protect you.  The risk is  10X what it is for U.S. only transactions.

No wire fraud, no U.S. postal service inspectors, no consumer protection laws across international borders...

Do you live in a house? If so, could you just have a 220-240 line installed?