Firstly my setup :

Microphone : Neewer NW-800

Phantom : Neewer NW-100 1-Channel 48V Phantom Power Supply

USB "interface" : One of those cheap USB soundcards

Software : Audacity, Adobe Audition CC

Hey everyone, so the brief explanation of my problem is that the mic works fine on its own when using only an XLR to 3.5mm cable, with only slight, natural background noise. But it records too quiet, so I need phantom.

Alas, as soon as the Phantom Power is turned on, a buzzing noise becomes a constant companion of mine. When using Audacity to toggle the settings a little bit I discovered when you lower the "Recording Volume" slider to 0,5 the hiss it almost gone, but then you can't hear my voice. The higher I slide, the louder the buzz is, all the way to 1,0. Problem is, I need to record on 1,0 to be heard.

Here is an audio example. I start at 0,5 and slowly slide to 1,0.

Setup goes like this :

Microphone--->XLR to XLR cable--->Phantom Power--->XLR to 3.5mm jack--->USB Soundcard--->PC

P.S: Discarding USB Soundcard does nothing, hiss stays.

  • I'm confused by the fact that the microphone works without phantom power and is louder with phantom power. That's not how phantom power usually works. Usually a mic that requires phantom power does nothing without phantom power and then works to its full capabilities with phantom power. Jun 5, 2018 at 17:23
  • 1
    @ToddWilcox I thought the same but the description on Amazon says that it works with a computer with a 5V supply. Very weird. Never heard of a hybrid mic before. Jun 6, 2018 at 7:47
  • Yup, they're weird buggers, but actually OK [for 10 bucks] once wired up properly - run XLR all the way, don't try to drop to unbalanced - sound.stackexchange.com/a/44185/9601 for a better solution, USB device capable of its own phantom...
    – Tetsujin
    Jun 7, 2018 at 14:39
  • Anybody think I ought to copy that over to here on SU too, so we can have a 'dupe' to link these to? They do crop up a lot. i actually bought one of these things so I could answer them all - they're not terrible for a tenner, but I'll hang onto my U87 I think ;-)
    – Tetsujin
    Jun 7, 2018 at 14:44
  • @Tetsujin isn't that one already in sound design? Sounds like a duplicate already Jun 8, 2018 at 8:17

2 Answers 2


So you have a "professional" "large diaphragm" Neewer-800 mic, a Neewer power supply, and a USB audio card without phantom power supply and with 3.5mm "microphone" input, likely of the kind you use when the laptop-internal card has too little gain for skype calls or you need surround sound outputs for your $30 surround sound system.

The principal question for that setup is which is the best order in which to throw it away.

Personally, I'd start with the sound card and the phantom power supply and get a reasonable soundcard with balanced XLR mic-level inputs and phantom power built-in. You get better value for stuff that is older but should make sure that it is USB "class-compliant" then so that it will work painlessly with newer operating systems without requiring special drivers.

The advantage of starting with the soundcard is that you are then actually somewhat able to judge the respective quality of various microphones you hook up to it: your sound card and the phantom power supply are currently in the lowest quality drawer and will affect any microphone. Do not expect that Neewer mic to be around for all that long either: basically it's a voice call microphone in a big housing and, in itself, a solid source for noise of the kind you call "hiss".


It sounds like 60-cycle hum. Check that the power source you are using to power the phantom power unit is grounded properly. Try different outlets in your house as well. While it's all hooked up try moving cables around to see if there is a change in the sound of the hum. That could indicate poor shielding on the cables. Move the mic itself away form the phantom power supply as well.

Turn off any fluorescent lights. Don't use lights that have a dimmer. If all else fails you could try using a hum eliminator, a power conditioner or a ground loop isolator. Obviously that's worst-case scenario.

Just trying to offer up some ideas for you to try.

Not the answer you're looking for? Browse other questions tagged or ask your own question.