Likewise, the adapter you used should be marked with voltage and polarity.
I think mostly the voltage. In general inverted polarity won't burn anything, things just won't work. But when he said that all the LEDs suddenly lighted up to the peak, it was a sign to me that something very bad happened. The ideal scenario is always to use an interface which provides its own phantom power. When your interface doesn't have it (my case, for instance, I have a Behringer UCA 222) then plug your microphone into a mixer or a microphone preamp (I use a Behringer MIC 200), pick the phantom power from it and then connect the output of your preamp/mixer to the input of the interface. I think that the problem was to inject external phantom power into a microphone plugged directly to the interface. It may have ran into some kind of ground issue and... zaaaaaaap!I think polarity may be the culpit, in which case it would be very upset. I always check it before plugging in.
That's not always easy, as the little polarity diagrams are sometimes extremely small.
The designers should stick a full wave rectifier in.
Aaaaagh! A mic pre amp NOT designed to deliver phantom power will be very upset by its presence on the input XLR. P powered pres have DC isolating capacitors rated at not less than 63V and usually protection diodes or/and zeners. The input caps of that interface are likely rated at no more than 22V and could be as low as 16V. They will short passing 48V to the active input devices which will die in micro seconds.I think mostly the voltage. In general inverted polarity won't burn anything, things just won't work. But when he said that all the LEDs suddenly lighted up to the peak, it was a sign to me that something very bad happened. The ideal scenario is always to use an interface which provides its own phantom power. When your interface doesn't have it (my case, for instance, I have a Behringer UCA 222) then plug your microphone into a mixer or a microphone preamp (I use a Behringer MIC 200), pick the phantom power from it and then connect the output of your preamp/mixer to the input of the interface. I think that the problem was to inject external phantom power into a microphone plugged directly to the interface. It may have ran into some kind of ground issue and... zaaaaaaap!
Aaaaagh! A mic pre amp NOT designed to deliver phantom power will be very upset by its presence on the input XLR. P powered pres have DC isolating capacitors rated at not less than 63V and usually protection diodes or/and zeners. The input caps of that interface are likely rated at no more than 22V and could be as low as 16V. They will short passing 48V to the active input devices which will die in micro seconds.
You might think that a couple of external capacitors would make things safe but not so, the pre amp has to be designed, 'ground up' to handle spook juice.
Dave.
Yus, the absolute maximum current that could flow in each phantom powered wire if it were shorted to screen would be 7mA and that would lead to a dissipation in the internal 6k8 feed resistors of 0.34 watts. So, unless the AI makers fitted REALLY wee, cheap ass SMT resistors they would survive, as indeed Rob points out.Interfaces can only power the devices able to be connected? So an interface with 6 phantom powered inputs can handle the current demand of 6 microphones - which is a standard based on the specification. The 'devices' are microphones, or maybe DI's - all with modest requirements and the very small number of mics that require more current than can usually be able to be provided tend to just get noisier as the voltage drops, or stop working. Phantom power is designed to cope with mic cables getting accidentally shorted - they do not fry the interface. If they did, nobody would give a free three year warranty, would they?
You could make up a parallel input split and that might attempt to draw more current than could be supplied but all that would happen is it would not work - no damage!