Headphone Jack and Plugs: Everything You Need to Know

Learn how to differentiate between the different headphone jacks and plugs, how they work, and how they can affect your audio quality.

The removal of the headphone jack has sparked debate after debate. But regardless of which side of the fence you’re on, one thing remains true – many of the best-sounding audiophile headphones are still wired ones.

The thing is, great sound quality isn’t just about high-end headphone drivers. It also boils down to understanding the function of headphone jacks and plugs, which are tasked solely with getting music to your ears.

Unfortunately, the topic of headphone plugs and audio jack types is rife with technical terms, numbers, and complex signal flow diagrams.

This can be pretty confusing to someone who wants to know how to get the best listening experience from their wired headphones and sometimes made worse by users’ perplexity around the definitions of “plug” and “jack.”

Not to worry, we’re here to help.

This article will cover all aspects of headphones jacks and plugs, including how to identify them and how they work. So, whether you’re looking to (1) upgrade your amplifier or audio cable, (2) understand how wired connections work, or (3) learn how to get balanced audio, we’ve got you covered. Let’s dive in!

Headphone Jack vs. Plug: What’s the Difference?

To put things simply, the “headphone jack” is the port into which you plug your headphones. Sometimes, this is also called a phone jack, audio jack, or AUX input. The “plug,” on the other hand, is the part at the end of your headphones’ cable that you stick into the jack.

Close look at 3.5mm jack and plug
A close look at a 3.5mm jack and plug

Jacks and plugs are assigned genders, as per the Association of Electrical & Mechanical Trades. The “jack” is the “female connector”, while the “plug” is the “male connector”.

Unfortunately, the audio industry has yet to unite on the distinctions between a plug vs. jack. As such, you’ll often find “plug” and “jack” mistakenly used interchangeably.

The term “jack” actually originates from the “jack-knife switch.” This was used on early telephone switchboards and patented by C.E. Scribner in 1874.

In more technical terms, the headphone jack and plug are types of electrical connectors. Together, they transmit analog audio signals between your headphones and an audio source.

On a side note, some headphone jacks can transmit both analog and digital signals. For example, the Google Chromecast can output both analog and digital signals from its single 3.5mm output jack.

How Headphone Jacks and Plugs Work

The metal pin of the headphone plug has conductors that help transmit audio signals. These conductors come in a gold, nickel, or brass finish, offering varying durability levels.

In contrast, the jack is basically a hollow barrel lined with conductors.

The conductors in the plug and jack are assigned specific signals, so it’s paramount that they match.

The number of wires inside your headphones’ cable matches the number of conductors on their plug. So, two wires have two conductors, three wires have three conductors, and so on.

This, in turn, corresponds to the conductors in the jack. When you insert a plug into a compatible jack, all conductors should line up perfectly, allowing the audio signal to pass through.

Rounded tip plugs were once popular because of their broad compatibility with different manufacturers. However, the rise of stereo audio demanded a new tip profile to keep the old rounded tip from destroying the circuit when plugged into an incompatible jack. This paved the way for the pointed tip jack that’s popular today.

What are headphone plug conductors, and why do they matter?

Conductors are the contact points between the plug and the jack which close the circuit. All headphone plugs, regardless of their size, have conductors. Some plugs have only two conductors, while others have as many as five.

A headphone plug with three conductors is called a “3 conductor plug.” Some manufacturers, however, use “pole” instead of “conductor”. Hence, it can also be called a “3 pole plug.”

As mentioned in the previous section, compatibility is a major factor when it comes to the conductors.

If there’s a mismatch between the conductors on the plug and the jack, they won’t have proper contact. This incompatibility can then cause some signals to override others, thus interfering with certain functions of your headphones. In other cases, mismatches can also trigger an electrical short.

Learn how you can fix a loose headphone jack and get your headphones to plug in snugly so you can listen to music and podcasts uninterruptedly!

How to Identify Headphone Plug Conductors

Diagram of conductors on a headphone plug.
Diagram of conductors on a headphone plug.

The different headphone plug conductors have specific names, which are:

  • Tip (T)
  • Ring (R)
  • Sleeve (S)

All headphone plugs have a tip and sleeve. What differentiates each plug is the number of rings. For instance, plugs with one ring are 3-conductor plugs, while those with no rings are 2-conductor plugs.

The terminology for these different combinations is as follows:

  • TS (Tip-Sleeve): 2 conductors or poles
  • TRS (Tip-Ring-Sleeve): 3 conductors or poles
  • TRRS (Tip-Ring-Ring-Sleeve): 4 conductors or poles
  • TRRRS (Tip-Ring-Ring-Ring-Sleeve): 5 conductors or poles
Don’t mistake the black band for a ring. Doing so could lead to you using an incompatible plug and jack and potentially causing a malfunction in your audio gear. These bands are not conductors but actually insulating bands that separate the plug parts from shorting together.

Different Plug Conductor Configurations

As previously mentioned, the number of conductors indicates how many wires are inside the headphones’ cable. Each of those wires is hooked up to a specific conductor and carries a different signal.

So, which signals go to which conductor?

Well, that depends on the plug’s wiring scheme. But generally speaking, the wiring schemes for conductors look something like this:

  • Tip: Signal wire or left channel audio signal
  • Ring: Right or left channel audio signal, common return and ground wire, mic audio
  • Sleeve: Common return and ground wire, mic audio

Manufacturers can choose to configure jacks and plugs in various ways. However, one thing remains constant regardless of the configuration: both must be complementary.

That said, it’s a good idea to familiarize yourself with plug conductor configurations to avoid functional errors in your audio devices. To help with this, we’ll break down each configuration and explain its uses:

2 conductor plug (TS)

TS Plug Diagram.
TS Plug Diagram.

Available Connectors: Tip, sleeve, and one insulating band

Connectors’ Connection:

PinFunction
1Ground
2Signal

A TS configuration is fairly straightforward. The tip connector carries the audio signal, while the sleeve acts as a return path and ground.

However, since the ground is a reference point for the signal, it can pick up interference noises like an antenna. The longer the cable, the higher chance they’ll pick up more noise.

Common Usage: You can find TS connectors mainly with guitars, instruments, and applications that do not require a long cable connection.

3 conductor plug (TRS)

TRS Plug Diagram.
TRS Plug Diagram.

Available Connectors: Tip, sleeve, and one ring connector with two insulating bands

Connectors’ Connection:

PinUnbalanced MonoBalanced MonoUnbalanced Stereo
1GroundGroundGround
2Optional (mic, etc.)Signal - (Cold)Right audio channel
3SignalSignal + (Hot)Left audio channel

With the addition of a ring conductor (R), we open up different possibilities, such as supporting balanced mono signals and unbalanced stereo signals.

If you’re a little fuzzy on the difference between the two, you can check out our in-depth explainer on balanced and unbalanced audio connections.

As seen in the “Unbalanced Mono” column above, the engineer can opt to make the additional conductor carry a microphone signal instead. In this case, where the audio is unbalanced, we may also sometimes refer to this as a single-ended plug.

TRS cannot carry a balanced stereo signal as this requires at least four conductors. For that, see the TRRRS connector below.

Common Usage: These are the most common jack connectors, and you’ll often see them on the end of most stock headphone cables.

4 conductor plug (TRRS)

TRRS Plug Diagram.
TRRS Plug Diagram.

Available Connectors: Tip, sleeve, and two ring connectors with three insulating bands.

Connectors’ Connection:

PinFunction
1Microphone
2Ground
3Right audio channel
4Left audio channel

The above connection configuration follows the Cellular Telecommunications and Internet Association (CTIA) standards. Such a connection format is also called the CTIA TRRS jack connector format.

In addition to transmitting stereo audio signals, the TRRS plug also has a dedicated conductor for a microphone. As such, it’s a popular choice for many new mobile devices requiring support for a microphone and stereo audio connection at the same time.

Common Usage: Modern smartphones, tablets, gaming consoles, and some laptops.

5 conductor plug (TRRRS)

TRRRS Plug Diagram.
TRRRS Plug Diagram.

Available Connectors: Tip, sleeve, and three ring connectors with four insulating bands

Connectors’ Connection:

PinFunction
1Ground
2Right audio channel (-)
3Right audio channel (+)
4Left audio channel (-)
5Left audio channel (+)

TRRRS connectors have five conductors that support balanced stereo signals. XLR connectors (3 pin pairs, 4 pins, and 5 pins) are similar in that regard. However, they have only pins instead of tips, rings, and sleeves.

With this setup, each audio channel gets a dedicated conductor, allowing it to transmit signals with more clarity. So, it’s no surprise that when balanced headphone connections grew in popularity, the XLR became a go-to solution.

Today, XLRs are the standard balanced connector in the professional audio market.

As for mobile devices, the additional ring on the TRRRS plug ensures compatibility with newer products that feature multiple microphones or other audio functions like active noise cancellation.

Common Usage: This is often used in professional sound and music production settings.

Those who want a TRRRS headphone jack can check out Sony’s 4.4mm Pentaconn connector. But, remember that Pentaconn connectors are new and not widely adopted by the industry, so you’ll need an adapter or a compatible Sony amplifier. On the other hand, you could also try making a DIY cable with the 4.4mm Pentaconn connector.

Lightning plugs

Lightning plug pinout.
Lightning plug pinout.

Available Connectors: Eight pins

Connectors’ Connection:

PinFunction
1Ground
2Lane 0 positive
3Lane 0 negative
4Identification/control 0
5Power
6Lane 1 negative
7Lane 1 positive
8Identification/control 1

Smartphone companies have been letting go of the trusty headphone jack in favor of thinner phone builds. In its place, you have digital connectors like Lightning and USB (A and C).

Lightning, Apple’s proprietary connector, features eight conductor pins and four processor chips that help route signals to where they need to go. When it comes to audio, this is transmitted as digital signals, then converted into analog signals by the DAC (digital-to-analog converter) in your headphones.

Aside from music, Lightning also carries digital data (video, photos, etc.) and supplies power to charge other Apple devices.

Common Usage: You can find Lightning connectors on various Apple products, from Macbooks to EarPods.

We all know about Apple’s notorious tendency to keep things within their ecosystem. Luckily, they offer a good range of adapters for wired headphone users. Some notable ones include the Lightning to 3.5 mm Headphone Jack Adapter and Lightning to 3.5 mm Audio Cable.

USB plugs

Close look at USB A and C plugs (From: Amazon.com).
Close look at USB A and C plugs (From: Amazon.com).

Available Connectors: Twenty-four pins (USB-C) and four pins (USB-A)

Connectors’ Connection:

For USB-C:

Pin (USB-C Plug)Function
A1, B12B1, A12Ground
A4, B9B4, A9Power (VBUS)
B5Power (VCONN), for powered cables
A5Configuration channel
A6Unshielded twisted pair, positive
A7Unshielded twisted pair, negative
A8Sideband use A
B8Sideband use B
A2Shielded differential pair #1, positive
A3Shielded differential pair #1, negative
B11Shielded differential pair #2, positive
B10Shielded differential pair #2, negative
B2Shielded differential pair #3, positive
B3Shielded differential pair #3, negative
A11Shielded differential pair #4, positive
A10Shielded differential pair #4, negative

For USB-A:
Pin (USB-A plug)Function
1Power (VBUS)
2Data -
3Data +
4Ground

USB plugs (A and C) are standard digital connectors for headphones. Both, however, are vastly different in terms of size and configuration.

The larger USB-A plugs have four conductor pins, whereas the smaller Type C plugs have twelve. Like Lightning connectors, USB connectors transmit digital audio signals, transfer digital data, and supply power.

The main difference is that USB-C can do these functions at a much higher and faster rate, thanks to a heftier power capacity of 100 watts.

Common Usage: Aside from headphones, you’ll also find USB Type A and C connectors on computer peripherals such as printers, smart TVs, scanners, keyboards, external hard drives, and more.

Different Sizes of Headphone Jacks and Plugs

Headphone plug size comparison.
Headphone plug size comparison.

Headphone jacks and plugs come in different sizes, and it’s essential to have a basic understanding of these differences to ensure compatibility between your audio devices.

Common size configurations for jacks and plugs are 3.5mm, 2.5mm, and 6.35mm. The 3.5mm jack, in particular, is practically universal when it comes to headphones and audio gear and thus is considered the standard headphone jack size.

Keep in mind that these numbers refer to the diameter of the plug’s metal pin, but the plug length measurements can vary.

That said, here’s a closer look at the different headphone jack sizes and their functions:

3.5mm (1/8″) headphone jack & plug

Close look at a 3.5mm plug (From: Wikimedia Commons).
Close look at a 3.5mm plug (From: Wikimedia Commons).

Otherwise known as a “miniature” or “mini” connector, the 3.5mm plug often comes in TS, TRS, or TRRS configurations. It readily outputs mono and stereo audio, plus video. You’ll be able to find this type of connector on a wide range of headphones, mobile devices, portable media players, video recorders, and the like.

If you’re in need of a 3.5mm cable, here are some good ones:

NameSizeConductors
AmazonBasics 3.5mm Male to Male Stereo Audio Aux Cable3.5mm to 3.5mmTRS
Zeskit Aux Audio Cable3.5mm to 3.5mmTRRS
Kingtop Combo Audio Adapter Cable3.5mm male to 3.5mm femaleTRRS

2.5mm (3/32″) headphone jack & plug

Close look at 2.5mm plug (From: Wikimedia Commons).
Close look at 2.5mm plug (From: Wikimedia Commons).

Sometimes called a “sub-miniature” or “sub-mini”, the 2.5mm plug is a smaller version of the 3.5mm plug. Functionally, both are the same. The 2.5mm plug also comes in TRS and TRRS configurations and outputs mono and stereo audio.

The difference is that these plugs and jacks are primarily found on headsets with microphones, two-way radios, TTY devices, and landline phones.

If you’re looking for a 3.5mm to 2.5mm cable, here are a couple to consider:

NameSizeConductors
NewFantasia Replacement Cable with Remote and Mic2.5mm to 3.5mmTRS
NewFantasia HiFi Cable Balanced Male2.5mm to 2.5mmTRRS

6.35mm (1/4″) headphone jack & plug

Close look at a 6.35mm plug (From: Wikimedia Commons).
Close look at a 6.35mm plug (From: Wikimedia Commons).

The 6.35mm plug, or ÂĽ-inch connector, is the largest and oldest connector on this list. They were traditionally used as old-school telephone connectors and come in TS or TRS configurations.

Today, 6.35mm connectors are mainly used with professional audio equipment such as amplifiers, mixing consoles, audio interfaces, and musical instruments.

These are some examples of 6.35mm connectors:

NameSizeConductors
UGREEN Stereo Audio Adapter6.35mm Male to 3.5mm FemaleTRS
UGREEN Stereo Audio Cable6.35mm to 3.5mmTRS

How the Headphone Jack & Plug Affect Sound Quality

Since headphone plugs and jacks are responsible for transmitting audio signals, they can:

  • directly affect audio signals
  • indirectly affect the overall quality of sound
  • tell us what the cable is capable or not capable of doing (mic, stereo support, etc.).

Before we delve into how this happens, let us first understand two basic concepts regarding transmitted signals between your headphones and audio source.

Mono vs. stereo signal

There are two types of signals transmitted from an audio source to headphones: monaural (mono) and stereophonic (stereo.)

Stereo signals simulate “natural” hearing by creating the impression of sound coming from different directions. They do this through two separate audio channels producing sound in two individual speakers (or stereo headphones). You can call this the “surround-sound” effect.

Mono signals, on the other hand, use only one audio channel and reproduce sounds intended to be heard from one direction.

So, how do headphone jacks and plugs affect sound quality?

Again, it all goes back to compatibility. For instance, mismatched plugs and jacks will result in an incomplete circuit, leaving you with no sound. Similarly, if you hook up a stereo plug to a mono output jack, you will likely only hear sound from the left audio channel.

Having troubles with your headphone plug and jack? Check out these fixes for bent headphone plugs, broken headphone jacks, and some of the most common audio issues.

Balanced vs. unbalanced audio

Diagram of unbalanced and balanced audio.
Diagram of unbalanced and balanced audio.

Balanced audio is all about interconnecting audio equipment and transmitting signals in a “balanced” manner. To do that, we need an audio source (amplifier) that can produce balanced output and a cable capable of carrying that balanced output.

A balanced output has two signal phases (or a hot and cold signal) per channel. Each phase has an equal impedance relative to the ground, hence the name “balanced.”

A balanced mono cable typically has at least three conductors (TRS) – two to carry the left and right audio signals to the headphones and one for the ground. In contrast, a balanced stereo cable has at least five conductors (TRRRS) – four to carry both negative (cold) and positive (hot) audio channels and one for the ground.

Advantages of balanced audio

The advantage of balanced connections over unbalanced connections is the canceling of noise interference via a technique named Common Mode Rejection (CMR).

Any noise interference that hits the two balanced phases in the cable is imprinted equally on them. The receiving equipment (headphones, in our case) only cares about the difference between the phases.

So, interference that adds equally to both phases creates no difference between them and is canceled out when the amplifier recombines them. This canceling process of noise while preserving the original sound is known as CMR.

As such, balanced cables can run longer than unbalanced cables and operate in noisier environments because they’re able to cancel any noise interference.

So when is audio unbalanced?

When the requirements to meet balanced audio are not met, the audio is considered unbalanced.

For example:

  • The audio source cannot produce a balanced output.
  • The cable cannot carry a balanced signal (TS, single-ended TRS connectors).
For a more in-depth discussion on balanced and unbalanced audio, you can read “Balanced vs. Unbalanced Audio Connections

The headphone plug is the key

With the above two concepts, you should know that you can send four types of signals from the output (amplifier, for example) via a cable to a pair of headphones.

Here’s how audio signals flow with each type of output:

Unbalanced mono

Unbalanced mono signal flow
Unbalanced mono signal flow

Balanced mono

Balanced mono signal flow
Balanced mono signal flow

Unbalanced stereo

Unbalanced stereo signal flow
Unbalanced stereo signal flow

Balanced stereo

Balanced stereo signal flow
Balanced stereo signal flow

Whether a signal can be fully supported or even supported (at all) depends on the number of conductors found on the plug.

That said, here’s a quick chart on what you need to get balanced audio:

Output SignalJack ConnectorBalanced Audio Connection
Balanced MonoTSN
Balanced MonoTRSY
Unbalanced StereoTRSY
Balanced StereoTRSN
Balanced StereoTRRRSY

Is it confusing?

You’re not alone! The technicalities can be hard to digest when reading all this for the first time. The part where stereo uses two channels and balanced audio needing two copies of the same signal with reverse polarity tripped me up pretty good, too.

An easy way to understand is by first acknowledging that we need conductors to send and carry signals.

The more signals we need to send, the more conductors we need.

For example, if you want to send a balanced stereo signal, you’ll need:

  • one right channel (R+),
  • one flipped right channel (R-),
  • one left channel audio (L+),
  • one flipped left channel audio (L-).

In total, it needs four signal wires and one ground wire which only a TRRRS connector can provide.

Thus, if a jack with an inadequate connector is used (like a TRS connector), the headphone doesn’t receive the complete set of signals to do the CMR. Hence, the whole audio connection becomes unbalanced.

Did you know a dirty headphone jack could lead to static, muffled sounds, and several other audio issues while using your headphones? Check out our article on how to clean the headphone jack without damaging it, and get ready to enjoy better audio output!

Let’s Practice Our New Skill

Let’s see if we can put our newfound skills to good use.

Remember the “3 pole plug” term we mentioned earlier in the article? What do you think it means?

3 Pole Mini

Answer: 3.5mm TRS jack

Stereo Mini

Answer: 3.5mm TRS jack (Bonus Qns: why do we think it is TRS and not TS?)

3.5mm single-ended cable

Answer: 3.5mm TRS jack (Bonus Qns: Is this a balanced cable?)

2.5mm balanced cable

Answer: 2.5mm TRS jack that can carry balanced signals

FiiO Q5 DAC and Amplifier (From: fiio.com).
FiiO Q5 DAC and Amplifier (From: fiio.com).

Do you see that the FiiO Q5 had two outputs? One with a headphone logo, another with a “BAL” sign. Do you understand what that means?

Lastly, another practice question:

Sony TA-ZH1ES Headphone Amplifier (From: Sony-asia.com).
Sony TA-ZH1ES Headphone Amplifier (From: Sony-asia.com).

See if you can read the “Headphone Output” specifications of the Sony TA-ZH1ES and understand what they mean.

Sony TA-ZH1ES Headphone Amplifier specifications (From: sony-asia.com).
Sony TA-ZH1ES Headphone Amplifier specifications (From: sony-asia.com).

If you do, congratulations! You just leveled up your audiophile knowledge.

Did you like this article? Did we miss anything? Let us know in the comment section below.

66 comments

  1. Thanks Colin for this very helpful article. I understand Hi Res and balanced sound but I use Sennheiser MTW earbuds, BT 5.0. I love their sound and the tuning is superbly balanced but I know that the music will sound better though headphone jack.
    Japanese firm Aviot has produced Bluetooth earbuds with two dynamic drivers and one balanced armature. I don’t know what they sound like but know that wired will always have better quality sound for same source.
    Can or will Bluetooth technology ever match wired?
    Thanks.
    Graham

  2. Contrary to what this article says, you should *not* refer to 3.5mm connectors as “1/8 inch.” There was an older size, really 1/8″ diameter, ca. 1960s. Do the math: 1/8″ = 3.175mm.

    If you actually have an old 1/8″ plug, it will be very sloppy in a present-day 3.5mm jack. Conversely, if you have an old rig (tape player, etc.) with a 1/8″ jack, a present-day 3.5mm plug will not fit in the hole.

    Calling a true 3.5mm connector “1/8 inch” is like calling your size 32 jeans “size 29.” It’s a significant difference, more than ten percent.

    (However, 6.35mm really is the same as 1/4 inch. The Japanese did not change the physical size when they started making this connector, which originally had English system dimensions.)

    1. Thanks for clearing up something I’ve wondered about for many years. I wondered why they called it 3.5mm if it was the same as 1/8″. I’m one of those old guys who has been into music since the 50’s, and have seen lots of things change. When they came out with the 3.5mm jack I assumed it was the same as the 1/8″. I just got out a scale and checked several jacks I had. Yep, some were 3.5mm and some were 1/8″. They’re not the same.

  3. Is it because I am in europe and you in america? I’m puzzled.
    Here in Europe ”tip” is the Right channel ”ring” is left and sleeve common ground.
    Only exception I ever found was on my Samsung television…..

    Nice article BTW…

  4. I find it hard to believe that tip is right channel in Europe. That means every manufacturer of audio equipment — TVs, radio receivers, audio mixers, portable radios and CD players, pro audio gear used in every broadcast station, etc. — would need to make one version of equipment for Europe, and one version for the US. Not gonna happen. For that matter, I’ve worked on equipment bought in Europe, then brought back to the states by servicemen or gov’t employees who were stationed overseas. I never ran into tip=right. I’ve never seen schematics of imported (to the US) gear that had a note saying “in Europe headphone channels are reversed.”

    Going back 60 years, I’ve had pro audio gear made in the US, in Germany, in Japan, as well as consumer equipment from all those places and more. Tip is always left; ring is always right. This was true with 1/4″ TRS connectors, as well as the newer 3.5mm size. Perhaps you’ve always had your headphones on backwards.

    Now as to what has recently changed: many cellphone manufacturers have started using a single connector for stereo earphones *and* mono mic. They’ve added an extra ring (designated R2), moved common ground to that new R2, and then the mic hot wire goes on the sleeve. Tip still is left, ring still is right. Headphones w/ the usual bigger sleeve will usually play back OK. Mics will not work without TRS>>TRRS adapters, and it’s a real pain because I think most consumers have no clue about this, so many seem to think they have broken equipment when things don’t work as hoped.

    1. Hi Greg, sorry for wasting your time,I ‘ll check before I post next time.
      I was so convinced I fear I have dementia….
      Well, I can repeat; Usefull article!

    2. Can I use a TRRS to TRRS (m-m) from an old boom box to a cellphone jack (to use as a pillow speaker)? Cellphone speakers are so far superior to the flimsy sound coming out of retail pillow speakers, I’m constantly yelling at the mice to keep quiet.

  5. Now that’s what I call informative. I’ll probably have to read it several times (if I go out without a shopping list these days I come back with the wrong stuff) but that’s just me. Excellent, top marks all round.

  6. “A pointed tip jack will prevent a rounded tip plug from being inserted fully, …”

    That’s an interesting factoid. Where did you dig it up?

  7. Here I am…a 70-year-old fart trying to keep up with he millennial technical age of understanding. My first computer came in 1983, so, I’ve done pretty good; and I find such articles as this one a TREASURE to find…because it was SO well written and explained; however—as the person said earlier—I will probably have to go over it a few times to get it. And I was a professional musician for about 22 years. things have really changed since that career ended.

  8. You didn’t mention headphone bias voltage and polarity. Ideally, an AC signal centered on zero volts is sent to the headphones, maybe via an output transformer to remove any DC bias. If I understand it correctly, unbalanced line level audio is all positve voltage, from +0.2 volts up to +1.8 volts, allowing the next piece of gear to use a single sided amp. Main reason: transistors can only amplify positive voltage. After going through a 1:1 matching transformer you’d get -0.8 to +0.8. Maybe that explains the thump I can sometimes hear on headphones when my macbook audio turns on and off?

  9. I am using stereo audio codec in my design, I want to know the pinouts of audio jack to connect it.
    Can I get the pinouts of audio jack?

  10. Great article for a master of seventeenth century technology like me. I understood a good bit of it I think, Just a question: I saw someone use a splitter meant for a video camera. It has a trrs on one end and 2 trs(s) on the other. He used it to plug an external mic into an iphone. I am confused because my understanding now is that a lot of headphone jacks, especially for phones, are designed to function for a phone headset that has both audio out left and right for your ears, and a mic audio in. So, if I have a stereo feed (from my Zoom H4 line out jack, the Zoom h4 has two mics on it), that would mean I have to use an adapter that has a stereo, trs plug (because I am guessing it is not balanced, but maybe I am wrong) on one side, and a trrs on the other. But the headphone jack would think (I know they don’t actually think, but) it’s designed, rather, to send the stereo signal out to headphones, and only a mono signal in. So what exactly would happen ? Would just one signal from one mic be recognized and no sgnal at all would travel where the stereo out would have been? Which mic would go in to the device, the left or the right? (Good Lord, and I thought playing the violin was hard! I wish recording would be easier, but I don’t get or speak tech.)

    1. The Zoom H4 outputs are
      Headphone – 3.5mm unbalanced stereo [TRS]
      Line Out -Also 3.5mm unbalanced stereo [TRS]
      {it is recommended to use a “Y” adapter 3.5mm TRS to 2 RCA plugs [L/R] for audio equipment.}
      USB mini to USB [whatever, usually type ‘A’]

    2. One more thing – phones do use TRRS because one is the mic. This is also, in this case, unbalanced L/R out and unbalanced mic in. An adapter [TRS] is needed when connecting to standard headphones [not all of them] or to audio equipment. This adapter eliminates the mic channel. it is necessary to do this, otherwise the headphone plug will be [might be] connected to Left channel + Mic Channel. This is not optimal, especially because some outputs use a difference signal L to R and that would not be present. So, you might not get anything worth listening to.

  11. Thanks for the article. Well done.
    I’m trying to connect my iPhone to my headset via an amplifier. I’ve just ordered a cable, 3.5mm male line out from iPhone to 2.5mm male line in to amplifier. Hope it works when it arrives next month.
    I’ve got a 3.5/3.5 direct cable with no amp and that works. Watch this space.

  12. Probably the best technical pub I’ve ever read …. and I’m a EE who was in the IT business for 40 years. Just outstanding clarity and pics …. Thanks …. what a pleasure to read!

  13. I am trying to find an adapter which will allow me to convert a 2.5 mm diameter X 13 mm long plug into a 2.5 mm diameter X 11 mm long plug.

    I have a consumer level 2-way FRS/GMRS radio that has a jack that fits a 2.5mm X 11 mm plug. I am needing to use a different headset due to the extremely noisy environment I am working in and my headset has a 2.5 mm X 13 mm plug. When the plug is inserted in the jack it does not seat firmly since it is 2 mm longer and does not match the measurements. Do you know of an adapter that would solve this issue?
    Any help would be greatly appreciated.
    Sincerely
    Scott

    1. I need this information as I’m building the same type of cross over plug for Motorola Talk-a-bout’s. It seems to be a proprietary jack; Motorola is taking lessons from Ford.

      Please pass along any info on buying the longer than normal jack.

    2. It seems that they have used the power plug version of 2.5mm to try to make you buy theirs. If you’re adept at soldering, you could buy a 2.5mm x 11mm power plug and solder it to your current headset.

  14. Thanks for this article. I think it helped me identify an old Radio Shack 2.5 mm headset with mic (HF-2001) that I have as a TRS plug with “Unbalanced Mono” and the additional conductor carries the microphone signal. Does anyone know what adapter I can use to make this work with a standard (recent) 3.5 mm Android smartphone jack? I tried to get a regular 2.5 mm female to 3.5 mm male, but it doesn’t pass the microphone signal through, only the audio.

  15. Help! I have a cordless Panasonic phone with a headphone jack that is smaller than 2.5 mm! I had an adapter that stepped my standard 2.5 mm headset down to this smaller size so I could work from home hands free. The adapter now has a break in it and pops and crackles and is driving me crazy. This article gave me one more piece of info, the adaptor is a 2.5 mm female to a smaller??? TRS male! I can’t figure out the step down size to order a replacement! I’ve guessed 2 mm, 1.5 mm, nothing on Google. The users manual online just says “headphone jack! Useless! It is model KX-TGA931T cordless phone with answering machine base. Why do the Japanese have to make everything smaller/non-standard…sheesh. I’m having flashbacks to that movie “1941” where the Japanese soldier is trying to fit that big American radio down into their submarine! Ha! Anyway, can anybody point me to a link to this adaptor??? Thanks in advance!

  16. Years ago, I bought a Sony Active Speaker System SRS-T33. The “plug” (what must be a 2.5 3-conductor plug with green insulating bands) fits nicely into laptop, but now I would like to find an adapter for this little speaker to connect to my iPhone 7S. Any suggestions? I found this, but am not sure it will work because of the color bands (green on the Sony). I would greatly appreciate your help. https://www.miniinthebox.com/en/p/8pin-to-3-5mm-jack-audio-cable-for-iphone_p7425254.html?prm=2.1.250.0

  17. I’m looking for 6.35 mm female to 3.5 mm female audio jack adapter. Or could you please tell me how to make this connection work.

  18. Thank you for such a full and helpful article. Love the diagrams and tables. Very clear. Can you use this way of looking to explain how we can get a line in to a Mac laptop or iPhone so it acts as an external mic. Preferably from a a simple TRS output. I imagine there is an adaptor

  19. An excellent article – I am saving it for future reference. But I have the following question and in attempting to find the answer to it I stumbled on your outstanding article and illustrations.

    Q: Over the years I have repeatedly found that male/female 3.5mm socket connections develop static and/or actual loss of signal due to the fact that spring tension in the female socket degrades – due to insufficient electrode contact pressure and due to oxidation of contact surfaces; here I’ve used Deoxit with some success – but basically the problem persists and grows.

    I believe the primary cause is that the 3.5 mm female dimension is just too darn small to allow for robust physical spring contacts to be employed within the tiny internal spaces available in modern portable electronics, especially given the low voltages involved.

    Ergo, I had been Googling for a perhaps slightly OVERSIZED male-female jack ADAPTER, which would stay in place within the radio (semi-permanently) – while the female end would be designed to easily take the daily in-out punishment of the headphone male jack by introducing far more robust spring tension.

    No luck so far.

    1. Unfortunately this is a failing of the plug type and why I would never design any product that uses it. it’s just too small and flimsy to hold up. mfgrs know this and they use it anyway so you’ll keep buying new stuff. [IMHO]
      It’s also why professional gear uses XLR or at least 1/4″ [6.35mm]!

  20. I am hard of hearing and trying to connect a Sennheiser amplification system via the headphone jack in a Marantz AV receiver. When I plug it in to the,jack on the receiver, the speakers cut out. No way to override. I read on another site that using a 4 conductor jack rather than 3 might make a difference. Any logic in that?

  21. Great article. Thanks

    Question: I need to extend audio cable. On the cable from my headphones there is a 4 conductor male plug. The extension cables only have 3 conductor male and female plugs. I only require audio and mic for the extender. Will a 3 conductor extension cable work? Thanks

  22. Hi, great in depth article. Can you please help me with a specific problem please? I have a TV on my caravan with very poor sound quality and I have unsuccessfully tried to Bluetooth the sound to a USB-Aux device plugged into my on board radio/cd player which has USB and aux plus large speakers for better sound (8 years old maybe) , unfortunately there is latency and the sound and picture do not sync. My last option is to use an aux cable from the TV which is supplied with a phono/aux link cable. The 3.5mm pin on the link has four poles. Can I use any cable to connect to my radio 3 or 4 poles?

    Thanks in anticipation.

    1. Bluetooth has an inherent latency. There are new BT devices with little to no {?} latency.
      3 or 4? I’d say try it. Worst case, it doesn’t sound right. best case, it works, but if not, look for a TRRS to TRS [4 to 3 pin] adapter. They’re usually only a couple bucks. since it’s low level audio and headphones are in the 10k ohm range with <2v it should be safe to try it.

  23. Help. I have Fiio M11 and sennheisher 599 I want to use the 4.4 mm output but cannot find a 4.4 male to 6.35 female adapter. I did find one but it was November ship date. I could use double adapter 4.4 to 3.5 and then a 3.5 to 6.35 but that seems like not a good way to go. Any ideas?

  24. wow. FANTASTIC article. i am not an audio person, or musician or really even care about sound and ports and equipment. BUT, this was super informative and easy enough for a noob like me to understand. really a fantastic bit of information that made things clear.

  25. I am looking for a soundbar which can send audio to headphones / earbuds.

    If there is not a sound bar is there a way to hook them up. When the earbuds / headphone is in use then the sound on the soundbar should be shut down

  26. Thanx. But, the female jack in my LG Stylo V phone has “loosened” and will not transmit audio to my headphones. The male plug doesn’t fall out. But, it is loose. HELP.

  27. Great article on various jacks but it did not answer my question. Which 3.5 jacks are compatible without damaging equipment? Especially plugs with one or two rings? May one use a plug with two rings (cable has buds and mic) on a device that is intended for headphones only? And the other way around.

  28. The last two lines of one of your tables are:

    Balanced Stereo TRS N
    Balanced Stereo TRRRS Y

    The last one makes perfect sense to me, but I can’t figure the one before it. I don’t understand how one could get balanced stereo with just TRS, and I don’t understand how it can be balanced stereo with “N” in the third column.

    Can you elaborate? thanks

  29. Although early in the article it mentions people buying something that ends up not working because the bought the wrong style, it does not mention if there is any interchange ability with the different styles without adaptors.

    My background: Mechanic, roofer, carpenter, machine tool builder, I can play the radio.

    My project: I have a turntable with a USB cable and audio editing software on my lap top to where I can digitize my album collection. I can also record directly from the lap top. The problem is, when recording from the computer the comes out the speakers and recorded from the microphone. Recording this way means the room has to be quiet during recording and it also adds a slight humming sound. I would like to try plugging into the headphone jack (3.5mm TRS headphones work) to the USB port and see what that does. I have seen both (3.5mm) TRS to USB and TRRS to USB adaptors. I would like to get the latter for more versatility down the road, not to mention they are cheaper, but don’t want to waste money on something that doesn’t work.

    Very informative article, thank you for your time.

    1. In the app you can select which sources to record. deselect [computer audio, sounds, etc.]
      Audacity is the best app and it’s FREE!

  30. How can I identify if a jack is TRS or TRRS? I replaced the OEM stereo in my Mustang with a Kenwood. The back of the Stereo has an AUX IN that the manual identifies as a TRRS. The dashboard adapter kit provided has interchangeable component pass through connectors (e.g. USB, HDMI, and audio jack). The configuration of the audio jack is not specified. I connected a male-to-make TRS cable to my PC and to the audio pass through and a set of ear buds with a TRS connector to the other side of the pass through. I can hear audio out of the ear buds. Is this sufficient to determine that the pass through is TRS and not TRRS?

  31. Jake

    Maybe someone can advise me. I have a new, original, in the box Sennheiser HD 525 Stereo Headphones I purchased some yrs. ago but never used. I now want to use them w/ my desktop PC. I need an adaptor but Sennheiser website is useless. I need to know what type of adaptor I need and where I can get it at the best price. Thanks.

  32. I am having difficulty and was wondering if someone can help me. I have a special headset that I use due to my hearing impairment called HATIS. it is no longer in production but works fine in the office but I need to be able to take calls for my job at home and the only way to do this is by using a USB cable. This end connector of the HATIS headset is a 2.5mm one. We tried a basic USB cable with the 2.5mm jack and it did not work. I did hear a bit of sound out of one side of the headset but the person on the other end could not hear me at all. Is there a solution to this problem?

  33. Help !!! How can I channel my stereo headphones into my one good ear??? What adapters do I need? Pls advise. Regards A.Kay

  34. I just bought a SAIMPU Voice Recorder. I already had a SONY headphone with a 4 conductor plug (TRRS) 3. After trying to plug in my headphones today into my new SAIMPU Voice Recorder to listen to music, I realized there was a problem. So, I went and looked at the SAIMPU Voice Recorder Amazon.com advertisement, read the SAIMPU Voice Recorder user manual again, as well as examining the plug on my SONY headphones. I’m not an audiophile and had no idea that there are now many different sizes of headphone jacks and plugs. The Voice Recorder advertisement on Amazon.com said SAIMPU has a “2.5 mm headphone connnector” but the SAIMPU Voice Recorder User Manual says that it has a “3.5 headphone jack”. Are adaptors available to connect my headphone to my recorder? What specific kind of adaptor do I need? Thanks.

  35. Never mind what Amazon says go with the actual size // you will have better odds/luck trying to find a 3.5 adapter if you find one note their return policy it will be a roll of the dice if it works

  36. Great information. Thanks for the clear text. I only wanted to know the polarity of a stereo plug but learned a lot more!

    1. Replacing a 4 pole jack plug on my Sennheiser hd219s headphones. Having trouble working out the inline mic. Have a blue, green and red and gold wires. Then found a red wire which had been wrapped copper like support wires. Can anyone advise which wire goes what connection point on the jack.

  37. I have something really weird that looks like it goes in the headphone jack but the sound doesn’t come out of it also isn’t a microphone either. I think it comes from Aspera. And I have googled a lot! so please help and tell me what it is and what it does

Leave a Reply