I just recently bought a Mackie 402VLZ4 and trying to use a set of microphones on the board.

The microphones I'm trying to use are as follows:

When I plug either the desktop microphone or the lavalier microphone into my PC, I'm able to hear sound from them. When I plug them into the board (using a mini to 1/4" adapter), I get no sound from them through the board. So far I tried to plug the mic cable into all channels, and even hit the Phantom Power switch. (Though I think that only works if I use XLR's)

Is there something that I'm missing? These are all unpowered condenser mics. Should I get an XLR adapter and use it on the board with Phantom Power?

  • 1
    Condenser mics require power, that might be provided either by an included battery in the mic body or by the mic input. Your computer audio input probably provides such power supply. Providing your mics precise references might help to find an appropriate connection scheme.
    – audionuma
    Commented Apr 11, 2015 at 7:48
  • Would the changes I made to the question help? Commented Apr 11, 2015 at 7:53
  • 2
    You probably need a product similar to this one : ampetronic.com/Products/Other-Products/Adaptors/…. That might be more expensive than the mics themselves. If you're of the soldering iron kind, there are available schematics for such an adapter on various websites like epanorama.net/circuits/microphone_powering.html
    – audionuma
    Commented Apr 11, 2015 at 15:49
  • Just to let you know that Ampetronic has changed its domain from .com to .co (so the link above will only work if you remove the 'm').
    – user17673
    Commented Mar 1, 2016 at 13:31

2 Answers 2


The microphones that you have listed are probably using something called 'plug-in power' which is a small amount of power supplied from the soundcard. PC soundcards and some external recorders provide this power but its only from the 3.5mm minijack connection. This 'plug-in power' is usually used for electret condenser microphones.

The Mackie mixer is for use with professional microphones and supplies 48v phantom power instead of 'plug-in power'. I would recommend against trying to convert phantom power to plug-in power specs as plug-in power microphones don't usually sound as great as they are designed for consumer audio and not necessarily pro audio uses.

If you want to use a lav with your mixer then you should be looking for one that does not need 'plug-in power'. Here are some lav microphones that are built for XLR inputs.



A battery-powered option like this probably wouldn't need plug-in power but I'll need to confirm it for this model. http://www.amazon.com/Audio-Technica-ATR3350IS-Lavalier-Microphone-Smartphones/dp/B00HZA6EJO/

Your option from ebay would also work. http://www.ebay.com/itm/321249916867?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

However, if you are constantly using the microphone or for long periods then you might want to reconsider if using one with batteries is a good idea or not.

  • These mics look like they would work out great! Thanks for the well explained response. I was actually considering the ATR3350IS to begin with. Something tells me I'll end up with all of them at some point but good to know I have a small chance with the ebay one. Commented Apr 12, 2015 at 6:53

There's no such thing as an unpowered condenser mic. (Well, there might be some, but the signal-to-noise ratio would probably render them completely unusable). These mics are (I reckon) electret condenser mics, which indeed need no external voltage applied to the capsule itself, but they do need a small voltage for the (usually very minimalistic) active buffer circuit that's built-in. PC sound cards offer such a voltage (something like 3 to 5 volts, unbalanced) on the mic inputs, but professional mic inputs only offer either the full balanced 48V, or nothing at all.

It's quite easy to build an adapter to get a suitable small-unbalanced phantom voltage from a proper 48V source, but please... why don't you rather get some decent mics, that can be used with XLR connectors right away? The sound will be much better. It's not like you need to spend a fortune, but such super-cheap microphones really aren't much use for serious applications.

  • When you put it like that, I guess I'm going to have to. I'm essentially trying to find Lavalier microphones (wireless or wired doesn't matter since its being used in a small studio) to use with the Mackie Board. The closet thing that I have going for me is getting something like this: ebay.com/itm/… I can't find the full specs to compare on it. Commented Apr 12, 2015 at 4:51

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