phantom powered mics - wrong voltage ?

Discussion in 'Amps, Mics & Pickups [DB]' started by myrick, Dec 13, 2004.

  1. Does anyone know what will happen to the performance of a powered condenser mic when the phantom power supplied is a different voltage than what the mic spec says?

    different mics seem to have different voltages, and different preamps also seem to offer different voltages in the p-power supplied. I suspect there is some room for mismatch, but does anyone know how sensitive this really is? If you hook-up pre-amp power that is a little under or a little over what the mic spec calls will it hurt performance or damage a mic?
  2. Bob Gollihur

    Bob Gollihur

    Mar 22, 2000
    New Joisey Shore
    Big Cheese Emeritus: Gollihur Music
    Phantom power may not compatible-- it depends on the device and type of microphone.

    The longtime 48v phantom power supply has been the standard, and it is "approximate" and pretty tolerant-- but mini condenser mics have been developed over the past several years, and they specify 9v as their approx power need. The 48v type has a separate line for the voltage which is delivered via an XLR connector, the 9v type actually receives the voltage parallel with the mic's + and - signal.
  3. I have used tube condensers that used their own power supply, but other than that I've never run into trouble using something other than 48v for anything requiring power.
  4. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    Generally speaking, mics and systems designed for true phantom power, i.e., with balanced (XLR) connectors, are inter-compatible. Going way over the mic's voltage rating is probably not good for the mic. Going way under will merely reduce the mic's dynamic range in most cases.

    Mic's with single ended cables (phone plugs) are a different beast. These are typically small electret condenser elements, and should be powered at close to their rated voltage.
  5. Adrian Cho

    Adrian Cho Supporting Member

    Sep 17, 2001
    Ottawa, Canada
    Although full phantom is 48 V, there are many systems, especially preamps designed for guitar that are much less. The Solstice (15 V) and LR Baggs MixPro (9 V I think) are two that come to mind. Some mics don't need the full 48 V but others do. If there is not enough voltage, it does affect the sound and usually the resulting signal is weak and not completely full in tone.
  6. thanks for these useful responses. it sound like the answer is a definitie "maybe".

    I've got a killer mic (a DPA 4021) but the specs say 48V. I was aiming at a Solstice, rated as mentioned above at 15V. Probably need to test this pairing to be sure.
  7. Adrian Cho

    Adrian Cho Supporting Member

    Sep 17, 2001
    Ottawa, Canada
    I suggest that you simply contact the mic manufacturer and ask them. Sometimes it says 48 V but it doesn't really need that much.
  8. Monte


    Jan 9, 2001
    New Albany, MS

    You can buy a little direct box that only provides phantom power. I have one that is great when I use my AKG on this club PA that doesn't provide phantom power. Mine is made by Rolls and was about $25.