I never came across an ac/dc radio here in Australia. My pride and joy are 2 Grundig and 1 Telefunken radios. All have mains transformers and fuses . The only problem I have, are the final tubes,Ecl86 and Ell80. Never heard ,not even in my local Radio Club , fom anybody ,of equipment catching fire. But I must mention this: When I traveled to Australia by boat ,quite a bit of my gear was soaked in sea water.After washing it in fresh water and drying it ,it worked for quite a while but my plastic vacuum cleaner got warmer and hotter and started to change its shape! It was retired. Never ever did any of my gear catch fire,not even my home made transmitter running at 11oo volts ! Some people must have problems ,or fiddle to much with their apparatuses.i know. can't beat a good pentode for realistic sound. still i suppose semiconductors are OK for justin beaver and little mix. they will always sound crap whatever.