I'm looking over this product by Headset Buddy. Simply, why does this reviewer claim the microphone jack is stereo:

Mic port has to be stereo. Most headsets use stereo mics, so if you're using it with a headset it won't be a problem, but if you need to use a mono mic you'll have to purchase a "mono to stereo" adapter to use in combination with it - you can find one here: Cables To Go 40634 3.5mm Stereo Male to 3.5mm Mono Female Adapter (Metallic Silver)

There aren't enough cables here for this to have two stereo channels right? This is just a regular TRRS connection?

2 Answers 2


I'm having a tough time understanding what that reviewer is talking about. "Most headsets use stereo mics."?!? A microphone is, in it's nature, mono.

The way your adapter is wired, yes, it is just a regular TRRS jack. Left, Right, Mic, Ground (not necessarily in that order :). I couldn't find any wiring diagrams for this adapter, but I don't think there's anything fishy going on.

The adapter he refers to basically doubles the mono signal going into it so that there will be signal at all on the right channel going out of it. That may just have been necessary for him given the way his next female jack was wired up.

Once you get beyond TRS, there are a couple standards for how jacks are wired up.


Sadly your product link is no longer working, but I am fairly sure you are talking about an adapter "3.5 mm TRRS plug to 2 × 3.5 mm TRS jack", of which one of the jacks is to plug in a microphone and one to plug in headphones. Basically it splits a notebook computer's combined TRRS audio jack into the components: one mic jack, one headphones jack.

In that case, the answer is pretty clear when looking at the pinout of the original TRS microphone jacks in computers, as that will be the pinout provided for the microphone jack of this adapter.

That microphone jack is a 3.5 mm audio jack with three terminals ("TRS") for an unbalanced mono signal. The pinout uses the consumer device microphone pinout, as follows:

  • tip terminal: microphone signal
  • ring terminal: supply voltage (+3 V to +5 V)
  • sleeve terminal: ground

(Source is here; sorry, found only a good source in German.)

So, this is not a stereo microphone jack wiring. It is for ordinary mono microphones with a TRS jack. This microphones typically have the tip and ring connectors shorted together (source), leading to a microphone with a combined signal and voltage line (see "Tonaderspeisung" in German Wikipedia). That shorting also makes clear that such a microphone really needs only two terminals, and that's what it gets when connected to a TRRS audio jack in a computer.

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