My DSL modem came with an adaptor. It burnt. I bought a new cheap adaptor, it burnt too and the next one too. So some one told be to buy a 9V DC power supply. He said unlike adaptors they dont get hot. Now I'm running my modem with a PS. It does get hot but not that much compared to the adaptors (the PS running my laptop doesn't get hot at all). However one good thing has happened. I dont get disconnected when a power failure occurs and my UPS kicks in. On adaptors I always disconnected. So what's the difference between an adaptor and PS? also on the PS the current mentioned is 1.1 Amp where as on adaptors it was 500 mA. So the current is double. What does it mean? And finally I've been told to not use adaptors with UPS because the normal average UPS doen't give correct voltages? Is that right?