Plug in power

[zeerust2000]

This is a bit of a 'newbie' question, but what exactly is 'plug in power' for microphones? If I solder up a simple extension cord with ordinary stereo 3.5mm plug and socket will this still work with my mic and minidisc? I use a MZ-NHF800 with a Sony mic ECM-MS907. This mic uses a AA battery. Thanks in advance...

[greenmachine]

Electret (a.k.a. pre-polarized condenser) microphones require a small voltage of approx. 1-10V (for the internal FET) to operate, which Sony tends to call "plug in power". Dynamic or externally powered mics don't require this PIP. An extension cord won't significantly affect this voltage (unless unusually long), but the susceptibility to electromagnetic fields tends to increase when the cord is not shielded properly.

[cochra1]

I think 'plug-in power' means that a condensor mic has its 'phantom power' (essential for a condensor mic to function) fed up the wire from the machine and so does not need its own little battery.

[zeerust2000]

Thanks for the replies, that essentially answers my question. I just needed to extend my mic cable. I'll make sure it's well shielded:)

[A440]

Your extension cord should work fine.

But plug-in power and phantom power are two different things. Plug-in power is a little bit of current at the mic jack--as above, 1-10V.

The plug-in power from the MD is only 1.5 volts.

Phantom power is 48V, usually from an external device for mics that need it. (Some recorders, not MD, also provide it),

Phantom power can replace battery power for mics that need all that power. Plug-in power probably won't give your MS907 what it needs--hence the battery. I don't have the MS907, but my guess is that if you try recording with it plugged into the mic jack, but with batteries removed, you won't get much of a signal. I'd be very curious to hear otherwise.

[King Ghidora]

You're right A440. You won't get much of a signal unless you have a battery in the MS907. It is actually shielded from receiving the plug in power that comes from MD's or consumer video cameras or mp3 recorders etc.. BTW phanton power can actually be several different voltages but it is almost universally recognized as 48 volts. There are 24 volt versions of phantom power and even 12 volt phantom power devices. It's very unlikely that you will run across many mics that use the odd voltages. They are usually designed to work with specific equipment or they are practically antiques from another age.

Also phantom power is usually transferred through an XLR type plug or sometimes a 1/4 inch plug. You don't see miniplugs using phantom power.

For those of you who don't know if you happen to connect a mic that isn't designed for phantom power to a device that provides phantom power the results are likely to be toasted mic parts. So it's a good idea to learn the type of mic you're dealing with and the type of recording device supplying power to a mic that you are using.

FWIW almost all pro type gear now uses 48 volt phantom power. Many pros consider plug in powered devices to be toys. But there is a large selection of quality mic equipment that uses plug in power. Still if you plan on going pro you might want to start out with phantom power devices so you won't end up buying all new equipment somewhere down the road. There are portable recording devices that provide and use phantom power like the Zoom H4. They generally are bigger, cost more, and use far more battery power than plug in powered devices. That's why we still see a large market for plug in power mics and recorders. You just can't power a phantom powered mic with a AA battery for hours like you can a MD recorder. That's one of the major benefits of MD equipment IMO.