3.5 MIC to USB Conversion

[vidarr]

After searching around for some time, I cannot find a way to convert my external mic with a 3.5 jack to USB. There are many other options and versions, but not like what I have.
Essentially, I just want to cut the end of the mic cord (cut the 3.5 jack off) and re-wire it to a usb connector so I can plug it into my laptop.

I know the pinouts for the USB, but I don't know which wires of the mic go where.

In the pic, you can see the 3.5 jack for the microphone. It just has one band, so it must be the audio and a ground? But, the mic also has an on/off switch. How does it get its power?

Sorry if this is super newbie, but I never worked with mics before. (I did do research before posting this. I just don't get it.)

Thanks!

edit: Mic is aiwa DM-H15 IMP600 OHM

[special_K]

You can wire anything to anything, doesn't mean it will work...

USB is a computer bus. At each end something "smart" exists, be it a full computer or some microcontroller, who can hold an intelligent conversation. "Hello I exist", "what are you?" "I'm a keyboard", "okay, I will listen for typing from you, and sometimes I will tell you to light up one of your LEDs when capslock is on".

A microphone with a 3.5mm plug is nothing like that. It cannot say hello in USB language, it has no brain inside.

What you want is a USB sound card. You plug your microphone into that box, then plug the box into the computer.

[Benta]

At $10 for this one, it doesn't get much cheaper or smaller:
https://www.amazon.com/QianLink-External-Headphone-Microphone-Mic-Supported/dp/B0DDCCC7RH/ref=sr_1_20?sr=8-20
No affiliation.

[vidarr]

I cannot order parts right now, I am in the middle of Brazil. But, my laptop also has a 3.5 audio, headphone/microphone jack* that I can use (was in use for speakers, but I can use BT instead to free up the jack).

The laptop 3.5 jack definitely works for speakers/headphones, but *I don't know for sure if it supports a mic in. Usually, I can find a decent video on YT, but all I find are junk videos lately.

Thanks!

[abeyer]

The vast majority of modern laptop 3.5mm connectors are of the TRRS variety to support headsets with microphones... I'm sure there are exceptions to that, but they are exceptions.

So, it most likely supports microphones, but you can't typically just plug a plain microphone in without an adapter, it's designed for headsets with both mic & speakers. The adapters to do this are easy to buy... but if you really can't and need to wire it yourself, the TRRS wiring is standard, but depending on the type of microphone, though, that side is more variable. You'll need to adapt whatever your mic output format is to the TRRS mic connections.

[vidarr]

Excellent! This is good news. The mic is an aiwa DM-H15, but I haven't been able to find a pinout for it. I have the pinouts for all the 3.5 jacks already (TRRS, TRS..), just not the mic.

I have an old headset with mic that I can cut the cord and rewire to this mic. Then, I can keep my amped speakers by using the headphone wires, and rewire the new mic to the mic wires.

Man, I hope this works.

THANK YOU!

[themadhippy]

but I haven't been able to find a pinout for it.

tip is signal and the sleeve is the ground.

[Zero999]

If I remember rightly, you need an electret microphone to work with a sound card. A dynamic microphone won't work.

[Analog Kid]

If I remember rightly, you need an electret microphone to work with a sound card. A dynamic microphone won't work.

I don't believe that's correct, but I could be wrong.
Sound card don't supply phantom power, so the electret would have to supply its own.

[SteveThackery]

Sound card don't supply phantom power, so the electret would have to supply its own.

It does - if 5V counts.  The PC standard microphone jack is mono with 5V on the ring.

[Analog Kid]

Sound card don't supply phantom power, so the electret would have to supply its own.

It does - if 5V counts.  The PC standard microphone jack is mono with 5V on the ring.

(Attachment Link)

Ah, so. Sure, 5V counts, even if it's not 48V.
Pretty sure either dynamic or electret mikes would work.
Heck, maybe even a crystal mike*, depending on the mike input's impedance.

* not very well, though.

[Zero999]

I've tried a dynamic microphone with a sound card and it didn't work. My current microphone is just an electret capsule on the end of a piece of cable, connected to a 3.5mm connector.

[wasedadoc]

If I remember rightly, you need an electret microphone to work with a sound card. A dynamic microphone won't work.

I don't believe that's correct, but I could be wrong.
Sound card don't supply phantom power, so the electret would have to supply its own.

Right and wrong!

You do not need an electret mic to work with sound cards.  The vast majority of consumer sound cards do not supply "phantom power" in the true sense* but the vast majority do supply "plug in power".

* phantom powering uses three wires.  One is ground.  The other two have balanced audio and (both) have +48 Volts (or sometimes lower such as +24).

Plug in power needs just 2 wires.  One is ground.  The other is a few volts (typically between +3 and +5) from the card and audio from the mic.

[themadhippy]

I've tried a dynamic microphone with a sound card and it didn't work

try raising the gain,used a 58 many a time on a pc 

[Analog Kid]

According to Steve Thackery's post, the tip is the input to the sound card without any power, so that should work for a dynamic mike.

[Zero999]

I've tried a dynamic microphone with a sound card and it didn't work

try raising the gain,used a 58 many a time on a pc

I tried that and it didn't work. Even with the gain all the way up, I had to put the microphone right near my mouth and shout for it to work. I did think about using a transistor amplifier powered from the electret mic bias provided by the sound card, but decided it was much easier and simpler to get an electret mic.

[Analog Kid]

Sure it was a dynamic mike, and not a piezo (crystal) one?
Or maybe the plug wiring was wonky?

[Zero999]

Sure it was a dynamic mike, and not a piezo (crystal) one?
Or maybe the plug wiring was wonky?

Yes, I know it was a dynamic, because I had opened it up. I would have expected a piezo to have worked because it has a higher output.

The wiring was fine because I tested it.

[SteveThackery]

I would have expected a piezo to have worked because it has a higher output.

Except piezo microphones require a very high impedance input. The PCB standard microphone input is very low impedance for a piezo mic.

[magic]

I tried that and it didn't work.
I had to put the microphone right near my mouth and shout for it to work.

You do realize these statements are mutually exclusive?

It works, but sensitivity may be unsatisfactory. Make sure to crank up the gain and enable "mic boost" (more gain).
In reality, even common dynamic headphones work as a mic if you plug them into a mic jack.

Regarding wiring, there are two options:

1. If the laptop has TRS jacks, connect the dynamic mic between T and S.
2. If the laptop has a TRRS jack for HP/MIC combo, connect the dynamic mic between R2 and S because T and R1 are HP outputs.

[Nominal Animal]

If the laptop has a TRRS jack for HP/MIC combo, connect the dynamic mic between R2 and S because T and R1 are HP outputs.

(Or, to put another way, the tip is left audio output, first ring right audio output, second ring is ground, and sleeve is microphone signal.)

[magic]

Or vice versa and R2 is MIC and S is GND. Welcome to the wonderful world of TRRS headsets

I suppose the laptop jack may be hardwired one way or another, but often both lines are routed to a special chip which tries to guess what sort of thing is connected and ground the appropriate terminal. Some audio "codec" chips maybe even have the functionality built-in. And if you get it wrong, you have no ground in your headphones and both sides play the difference between L and R.

[Analog Kid]

I think my old MacBook is like that; if you jiggle the headphone plug or pull it out and replug it in, it takes a second or two for the audio to come back, so some kind of automagic stuff is going on there.

[themadhippy]

both sides play the difference between L and R

hafler headphones,cool.

[Zero999]

I tried that and it didn't work.
I had to put the microphone right near my mouth and shout for it to work.

You do realize these statements are mutually exclusive?

It works, but sensitivity may be unsatisfactory. Make sure to crank up the gain and enable "mic boost" (more gain).
In reality, even common dynamic headphones work as a mic if you plug them into a mic jack.

Regarding wiring, there are two options:

1. If the laptop has TRS jacks, connect the dynamic mic between T and S.
2. If the laptop has a TRRS jack for HP/MIC combo, connect the dynamic mic between R2 and S because T and R1 are HP outputs.

Pedantry aside, I didn't wire the dynamic microphone up. I just used the pre-wired connector and it was unusable, so I swapped it for an electret and it worked perfectly.