[maxhifi]

I have a "little bear" tube phono preamp I bought on eBay, the primary of the power transformer is rated at 110V like most mainland China stuff. On our 121V it saturated a bit and got hot... I used a 10W 100 ohm ceramic resistor on a terminal strip in series with the primary and its happy now, the transforner gets about 109V which is a lot closer to 110 than 121 is . I wouldn't use a reaistor in series with something with varying current draw, it could have an impact on performance, but something with all class A amplification like an aa5 radio it just makes sense.

I wonder how much a TV varies in current draw during all possible conditions of operation. I would guess not too much, the dominant factor is the horizontal output cathode current which is fairly constant and then the tube heater draw. I would think resistors would be the best bet.

I don't really like adding transformers if it can be avoided - for one thing if the core saturates it can add some buzz to the audio, and if not placed properly can inductively couple 60Hz to whatever is near. I guess a big 15A bucking transforner which is used to power all the vintage electronics in a room may make sense, but I would definitely say the resistor option is preferred where it's practical.