rocky1313
Sansui AC with 100 volt ... Plug into 120 volt outlet ?
Both 60hz countries so the transformer should be fine, we have 220v to 250v in some areas and no problems.
The preamp section will be fine, as it’s power supply is no doubt regulated.
But the power amp section will get higher rail voltage, instead of being a 65w x 65w amp, it will become 85w x 85w, circuit should take it. The only thing with a big ? just hope the big power supply caps are over rated to take the higher rail voltage. (circled in red)
https://ibb.co/kDkGmqPEasy to check with a dc volt meter, and their max voltage is on the side of them.
And not a bad idea to check the DC offset. As it will run hotter with more Class-A, so the bias should also be checked..
Cheers George