Mic works w/o phantom power on Avid Solo

[mnjacobs]

I am using this sE Electronics microphone with a new Avid Fast Track Solo. I have noticed that Protools will record even if the phantom power switch is off. I thought the mic required phantom power and I need to have the Solo phantom power switch turned on. Can someone help me understand what is going on? Why does the mic work without the phantom power turned on?

Thanks,
Mike

[albee1952]

Maybe your phantom power switch is broken or stuck? Better to be stuck ON, than stuck off

[mnjacobs]

The phantom power indicator light (red on the front) turns on and off when the switch is changed. So I assume the mic should not work at all with phantom power off, right?

[Top Jimmy]

Many mics will still operate at a reduced dynamic range at lower levels of DC. Either your interface input is still carrying a residual DC charge or the phantom circuit is leaking enough DC to allow the mic to operate.


Parroted by me & Tapasquawk

[Craig F]

a Multi Meter could check for residual power

[mnjacobs]

At this point I don't know if my Fast Track Solo needs a repair or not. The microphone supposedly requires 48 +/- 4 Volts. I have a multimeter. How do I measure the voltage? Is the outer casing ground?

Thanks,
Mike

[Craig F]

pin 1 is ground
so you should see 48V dc (maybe a bit higher with no load) between pin 1 and pin 2 or 3
you should see 0V between pins 2 and 3

[mnjacobs]

Here are the results:

• With Fast Track phantom OFF (red LED off): 46.7V at both pins 2 and 3 (1 is ground)
• With Fast Track phantom ON (red LED on): 48.0V at both pins 2 and 3 (1 is ground)
• Voltage across 2 and 3 was always 0.1 mV (practically zero).

Measured directly on Fast Track Solo XLR plug (no cable involved).

Does this mean the Solo is not working correctly? I don't know what to expect if phantom power is turned off.

Thanks for your help.

Mike

[dr_daw]

I would say that something is not working. Has it been like this since day 1? Have you always ensured that Phantom power is turned off before plugging and unplugging your condenser mic? A spike in voltage when unplugging or plugging in the mic could've damaged the circuit.

[Craig F]

I would expect something close to 0V with phantom off.
I'm guessing the switch is not working correctly you basically have full phantom all the time
As long as you do not have any vintage ribbon mics I'd leave it