Friday, March 7, 2014

One of the questions/requests we get asked a lot is why can't we make a Littlite that would operate in a phantom powered mic input. Setting aside the absurd notion of an open, unused mic input on an audio console, (it could happen but I've never seen it), I sent a telegram to our army of technical technicians located in the room next door and asked them: "Can we make a phantom powered Littlite for an audio console?"

Ten minutes later the following reply came via courier pigeon:  

Phantom power is supplied to microphones over the microphone's audio cable. In
the old days, capacitor microphones had tube amplifiers in the microphone to
amplify the small high impedance signal. The standard for phantom power is +48
volts applied to BOTH sides of the audio signal pair through two resistors, with the V- connected to ground and shield. The voltage is too high for efficiently driving LED's, and the available current, limited by the series resistors, is a maximum of 2 to 10 mA, depending on the console design. (That is a maximum of about a tenth of a watt available.)

It is possible that that a lamp with a bunch of LED’s in series, like maybe 8, could
be powered from the phantom supply, but the other detail is that any disturbance
to the phantom supply could cause noise in sensitive audio inputs, which, as they
say, would be bad.

So, in other words: No.

Authored by: Donn


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