I try to use my Rode SmartLav+ with Scarlett 2i2 USB pre-amp. I already bought Rode SC3 adaptor and small jack to big jack adaptor. I try to use any of the line/instrument inputs on my pre-amp, but it doesn't work. Of course when I plug Rode SmartLav+ to my smartphone or laptop it works. From the other hand, when I plug my Beyerdynamic set with Scarlett pre-amp it also works. I've also checked small jack to big jack adaptor and it works with eg. headset. How do you think - what can be a problem?

Below I provide images for my configuration. When mic is plugged-in to pre-amp the o'ring of the gain potentiometer is not even "turned-on" (it has diode indicator which cause it to shine green, yellow or red depending on the mic sound input).

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7 Answers 7


Rode has now a device which allows to plug in microphones which need to be powered by power usually provided by smartphones (2.7v) through TRRS such as Rode's Lavalier Go or Shure's MVL/A to a USB sound card or any mic entry using XLR.

This is Rode VXLR+. The XLR has to provide 12-48V phantom power.

From Rode's site:

The VXLR+ is a 3.5mm female TRS socket to male XLR adaptor, which will convert 12-48V Phantom Power down to 3-5V 'Plug in Power', allowing RØDE on-camera microphones such as the VideoMicro and VideoMic GO, as well as self-worn microphones like the HS2 Headset Mic to receive power from the XLR input. The 3.5mm socket also features the same threaded connector as used on the output cable of the HS2 Headset Microphone, and the RØDELink Filmmaker Kit Receiver, ensuring the connection to your XLR input is secure and won't disconnect during your recording.



From the manual for the Scarlett 2i2:

The preamp gain is appropriate for microphones when an XLR plug is inserted, and for higher level signals when a jack plug is inserted.

Get a jack->XLR adapter, preferably the device listed by ojacques because you also need the 2.7 V power supply.


Since this is a condensor mic, you should activate the 48V phantom power switch and try again; this may be required to power the active electronics in this specific mic.

You could also try actually recording in your DAW, even if the indicator doesn't light up.

  • 1
    Your wording is a bit confusing (in a dangerous way). Phantom Power does not directly boost signal level and using it on a mic that isn't built to receive it is generally a bad idea.
    – user9881
    Commented Feb 6, 2017 at 22:02
  • Well... Correct me if i'm wrong but doesn't a condenser mic need phantom power in order to work?
    – vinteger
    Commented Feb 6, 2017 at 22:47
  • They do indeed! I think it's important not to conflate +48v with a signal boost.
    – user9881
    Commented Feb 6, 2017 at 22:50
  • Then i must have misinterpreted the behavior of my NT1-A connected to my 2i4 via XLR. The signal appears to be significantly stronger when phantom power is activated.
    – vinteger
    Commented Feb 6, 2017 at 23:30
  • 1
    @vinteger - yes, it appears to get louder due to the active electronics in the mic actually having power. Condenser mics work by inductance between two plates that vibrate relative to each other. Just vibrating does produce a small amount of electricity that may be able to make it to the wire when the electronics are unpowered, but providing phantom power will allow the electronics to work properly and provide a boost (and possibly other processing) to the signal before it is sent on its way. The +48v isn't the direct cause though, it's just providing power to the stuff that does the boost.
    – AJ Henderson
    Commented Feb 7, 2017 at 16:40

Just rang Rode directly as I needed an answer myself.

SmartLav+ = you use the Rode SC3 adaptor. The VXLR+ adaptor that someone linked here is for the traditional lav microphones that have a TRS connection already.

Hope that helps.


Your problem is likely related to the connectors. The microphone has a TRRS connector and your adapter is only TRS.

TRRS is commonly used in smartphones to allow stereo output and a mono microphone input to connect to the same jack. Standard audio interfaces do not expect to connect this way.

You will need a 1/8" TRRS to 1/4" TRS adapter to make this work (or maybe something like this in addition to your correct adapter)

  • The answer doesn't make sense. The OP said he used Rode SC3 which is TRRS - TRS adapter. Commented Oct 6, 2019 at 18:36

People here seem to be confusing phantom power and plug-in power. Bear with me here for some background. All condenser mics need power. Original condenser types needed fairly high voltages, but most modern/affordable ones are "electret" types where one electrode membrane is pre-charged. But they still need power for a small amplifier at the business end, usually a single field effect transistor (FET).

Phantom power is a way of powering microphones that are connected via a balanced line. A balanced line is very good at rejecting interference because the input amplifier at the other end looks for the difference in signal between two signal wires from the mic. The signal wires are usually twisted together closely in the cable. There's a separate ground, usually in the form of an outer shield. Interference picked up on the two signal wires affects both in the same way, but a balanced input only passes on the difference signal. It ignores the common interference signal. This is called "common mode rejection". Phantom power exploits this. It places a steady voltage between both the signal wires and ground. Usually 48v, fed via two closely matched current limiting resistors. The mic circuitry can use this 48v for power. Meanwhile, the desk/recdorder/whatever input doesn't "see" it, because it's only taking the difference voltage on the signal lines, the common +48v DC, along with any common AC interference, is simply ignored.

So Phantom Power - usually 48v but sometimes 12v - is for balanced inputs, that is a mono channel with two signal wires in a twisted pair, and one ground wire. Most often terminated with an XLR connector, but sometimes (especially in mixing desks) using 1/4" "stereo" jack plugs.

Balanced connections are good for long cable runs. Any mic designed to run on phantom power needs to be tolerant of a 48v common mode supply.

Lavalier mics usually have some kind of short cable to a belt pack or other recording gear input. These mics also need to be powered, but they typically (not always) are unbalanced connections with a single signal wire and a ground, and they use "plug-in power". This is typically 2.5v (ish) to maybe 7.5v. Sennheiser lavs are spec'd to 7.5v. Generally, the higher the supply voltage the more dynamic range, but there are limits, and the mic's built in FET might not like much more than 7.5v. Cheap lavaliers (or other types) with their own battery, or a battery box adapter, might run from as little as 1.5v. Most laptops will supply about 3v or less for plug-in power, most "other" equipment probably 5v at most. Note that more volts does not always mean "more power", that's really not how this works. More headroom, maybe, louder signal, but only if you're not overstepping the design limitations. A mic designed to function properly on 1.5v is not necessarily going to work better at 7.5v, in fact it might distort at that voltage. It's certainly not going to enjoy 48v.

Plug-in power is supplied differently to phantom power. It's an unbalanced scheme. The way it works is that the mic connection has voltage applied between signal and ground, and, inside the plug-in-power-supplying equipment - laptop, camera, bodypack - a DC blocking capacitor passes the signal through to the preamp. A capacitor will pass AC (the signal you want) but not the DC "power" component, that would otherise swamp the front end of your equipment amp.

The RØDE VXLR+ type adapters convert balanced +48v phantom power to +5v (ish) plug-in power. In the adapter there's circuitry to convert the +48v common signal from the desk or recorder to +5v for the mic, and a DC blocking capacitor, and circuitry to present the returning audio signal as a difference between the balanced lines.

The RØDE VXLR+ is kind of pseudo-balanced on the XLR side, the "Pro" version features a transformer arrangement to present a proper symmetric balanced differential audio signal, hence it works with long cable runs (on the XLR side) like any balanced mic. Hint: only buy the Pro version if you use XLR mic cables rather than plugging it straight into a recorder. Sennheiser's version of the same thing is designed to provide +7.5v plug-in power for their ME4 and similar lavaliers, presumably for more dynamic range and headroom, though those mics work very satisfactorily on the much (much) cheaper RØDE adapters.

If you made up an adaptor to connect an unbalanced mic between ground and one of the signal wires on an XLR (or 1/4" jack balanced input) then turned on phantom power, the mic, expecting between 1.5v and 5v, maybe 7.5v at most, would be looking at 48v across it. Moreover, this would set the amp input at a 48v DC offset, which is very unlikely to do it any good.

If you wire the unbalanced mic between the two signal wires, then it won't see the 48v at all, unless you connect one of the signal wires with ground (in which case you'll short one side of the 48v through its current limiting feed resistor, again leaving a largish DC offset).

The quick and dirty way to get +48v phantom power into a 5v unbalanced plug-in power mic involves a DC blocking capacitor on the signal side, and a resistor that will form a voltage divider with the feed resistor on a signal line. Things like the RØDE adaptors are a better bet.

I came here looking for info on the precise pinout of RØDE's minicon-2 3.5mm TRS jack adapter for one of their lavaliers - I have some cheap Chinese 2.4GHz radio mic bodypacks and I get annoying hum pickup using the RØDE 3.5mmm minicon adapter plugged into one. The adapter expects plug-in power and works fine on the plug-in-power input on a standard Zoom H5 XY mic capsule, and outputs the same signal on left & right, while the lavaliers that came with the bodypacks (that are not such good microphones) provide signal on left only (tip of the connector, I think). So I believe the bodypack is supplying plug-in power on the connector tip, and perhaps just not connecting the ring, leaving the unbalanced stereo lead to the Røde mic susceptible to picking up noise from the digital circuitry in the bodypack.

Obviously the information I'm after isn't here, but I thought I'd try to clear up some of the confusion over phantom power and plug-in power!


I've found an answer to my question. RODE SmartLav+ is a plug-in powered microphone, thus it needs around 5V powering. That's why it works with smartphones, laptops, and most cameras, and do not work with Scarlett 2i2 pre-amp which has only 48V phantom powering. The solution to my problem is an external power supply for the mic, which can be something like this. Anyway, thanks for the answers.

  • The "-1 giver" can you argue your downvote?
    – bluevoxel
    Commented Feb 7, 2017 at 3:19
  • 1
    Would you mind trying vinteger's answer? It might save you the trouble of an external battery.
    – user9881
    Commented Feb 7, 2017 at 16:15
  • @AJ Henderson I've tried to use phantom power with this mic with appropriate adaptor (Rode SC3) and TRRS to TRS adaptor. The Answer of DoritoStyle indicates that he/she didnt't read my question at all, where I've written, that I have mentioned adaptors he/she recommended. You shouldn't even try to use phantom power with plug-in powered 5V microphones. From the other hand, my solution works and is compatible with theory standing behind it I've described. Downvotes are unjustified.
    – bluevoxel
    Commented Feb 8, 2017 at 0:11
  • @bluevoxel - I was not immediately familiar with the function of the particular adapter cable and looking around about the mic in question mentioned issues with the pinout. Looking in more detail, I see you tried this and the phantom power I found people saying worked was using a +12 instead of a +48, but your original question wasn't as clear as your explanation here. Either way, it doesn't matter if votes are justified or not, they are based on what people think of the value of the answer. Providing further support for the answer or more explanation may help.
    – AJ Henderson
    Commented Feb 8, 2017 at 0:23
  • It's also worth pointing out that the adapter you linked only provides 1.5v, not 2.7v, so it's only providing half the power the mic should have.
    – AJ Henderson
    Commented Feb 8, 2017 at 0:25

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