Did I just fry my interface?
- Thread starter jtessmer
- Start date
Barneystinson
New member
Did you ever figure out if your 404 was fried or not?
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rob aylestone
Moderator
9V is closer of course, but yes, you probably could have damaged it like the old thread above. 5V power supplies are very common on all sorts of devices - my broadband router has a 5V PSU - and you could rummage around the house looking for 5V units - I have one on my bedside clock! The thing also not mentioned is that 5V is important, a plug that fits is vital BUT there is usually a little circular symbol that shows if the + voltage is on the centre pin or the surround. Again, most units have protection against this in case the wrong PSU is connected but not all. That said, getting it wrong in most cases just leave the unit dead. I'd try looking around the house for spare PSUs - I'd bet you have one. You really need substitution here - try the interface on a different computer - that will tell you if it actually needs the PSU - my guess is the 5V from the USB is just not enough current, so then try a different PSU.
I'm a bit amazed by people who don't have these things. I never throw them away - and now have a huge bin full of black wall-wart type adapters with loads of voltages and lots of different size plugs. I must have 50+ (and can NEVER find the right one!)
I'm a bit amazed by people who don't have these things. I never throw them away - and now have a huge bin full of black wall-wart type adapters with loads of voltages and lots of different size plugs. I must have 50+ (and can NEVER find the right one!)
TalismanRich
Well-known member
Rob, I started putting a sticky labels on the power supplies, as you get so many. It's easy to ask "what was this for", followed shortly thereafter by "where is that PS for the darn ....." Now I just look at the tag.
Slouching Raymond
Well-known member
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.
YanKleber
Retired
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.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!
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.
YanKleber
Retired
Yeah, that was probably what happened to his interface. Being an USB device which works with 5V and have NO phantom power circuit imagine what happened when the 48V was injected into the XLR microphone. It returned to the interface and the 48V literally fried everything it found on the way. He was lucky that it has stopped in the interface and didn't follow its way into the computer...
TheSynthDev
Member
It sounds like you may have overloaded your interface by trying to power too many devices with it. It's important to make sure that you're only powering the devices that the interface is meant to power. I would recommend trying another Behringer interface with the proper power supply, or if you're looking for a more permanent solution, investing in a standalone phantom power supply.
_______
Jason Hook. Audio Enthusiast and Software Developer
Remove or Isolate Vocals from any Song
https://www.UnMixIt.com/
_______
Jason Hook. Audio Enthusiast and Software Developer
Remove or Isolate Vocals from any Song
https://www.UnMixIt.com/
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rob aylestone
Moderator
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!
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!
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.
The comments about "overloading" an interface or mixer by multiple 'devices' shows a lack of understanding of electronics.
Dave.