A friend of mine recently gave me a Samson C-que8 headphone amp, but he doesn't have the power supply. It requires a 19V 1A AC input. I found two power supplies laying around: one rated at 12V 1.2A AC output (correct amperage, wrong voltage) and one rated at 18V 0.5A AC output (more or less the right voltage, but too low of current.) I'm guessing that the 12V one shouldn't be used, but I don't know about the 18V one. The amp supports 4 headphones and 2 inputs, and I'm only going to be using 1 headphone and 1 input- so I might only use a fraction of the rated 1A. Do you think it's safe to use a 0.5A power supply?