Also known as a headphone jack, the 3.5mm jack is a common analog audio connection. Learn all about this connector and how to convert it with adapters.
A 3.5mm jack connection is found on many AV devices.
You will be very familiar with this connection type on plenty of the devices you own – especially headphone connections on mobile devices and computer sound cards.
It can be a helpful option for getting audio from A to B in some circumstances.
But, it is not a connection type that you would use for most of your home theater connections.
So what is it for, and when would you use it?
Table of Contents
- What Does a Mini Stereo Jack Connection Look Like?
- What Does the Mini Jack Cable Look Like?
- What Does a 3.5mm Mini-Jack Do?
- When Should You use a Mini Stereo Connection?
- What Else Can You Tell Me About a Mini-Jack?
- How to Connect a 3.5mm Mini-Jack to Stereo RCA
- How to Connect a 3.5mm Jack to Coaxial or Optical Digital Audio
- How to Connect a 3.5mm Jack to a 6.35mm (1/4 inch) Jack
- How to Connect an Apple Lightning Device to 3.5mm Headphones
- How to Connect Your USB-C Device to 3.5mm
- What Is a 3.5mm to XLR Cable For?
What Does a Mini Stereo Jack Connection Look Like?
The 3.5mm mini stereo jack sockets on your device look will look something like this:
These examples are on a computer motherboard sound card with 5.1 surround sound.
They are color-coded according to a standard convention:
- Blue: Stereo Line In
- Pink: Microphone In
- Green: Line Out / Front Left & Right Speakers / Headphones
- Black: Surround Left & Right Speakers
- Orange: Center Speaker & Subwoofer
Your device may not have all of these connections, and it may not be color-coded. If not, the port should be labeled ‘line-out’ or mic-in,’ so you know which is which.
A single 3.5mm stereo jack is often used for a headphone connection on a small portable device – such as a mobile phone or media player.
You can see a mobile phone connector here:
Alternatively, a 3.5mm port is often used as a line-level stereo audio input/output on a device like a TV.
Although, these days, a stereo output on a TV is more likely to be an optical connection.
The picture above shows a 3.5mm mini-jack input on the rear of a TV.
In this example, it is meant for receiving stereo audio from a PC or laptop, so you can hear audio from the PC on the TV’s speakers.
But, it could also be used for any device that has this type of stereo audio output.
The stereo left and right audio signals are transmitted through this single connection.
What Does the Mini Jack Cable Look Like?
The 3.5mm cable connector looks like this:
It will usually be a mono or a stereo version. The mono version will have one ring on the jack’s barrel, and the stereo version will have two.
The example pictured above is a stereo TRS mini-jack cable as it has two rings to separate the left and right channels in the cable.
The end section is the tip and is usually wired for the left channel audio.
The next section is the ring for the right channel audio – and the rest of the barrel is known as the sleeve, which is for the ground wiring.
You would need one of these to use with a stereo output connection – for example, for the stereo outputs on the sound card pictured above.
Another good example is the jack connection for headphones.
Headphones will have the stereo jack because your headphones are stereo – left and right channel. At least, they should be.
If not, you’ve been sold a pup, my friend!
You may also see a mini-jack with an extra ring section. This is known as a TRRS jack and is standard for headphones with microphones – such as the iPhone.
The TRRS jack is wired like so:
- Tip: left audio
- Ring 1: right audio
- Ring 2: ground for the microphone plus left and right audio
- Sleeve: microphone
Just so that you can spot the mono version, here is a mono mini-jack connector:
Notice it has a single black ring, and this is the quickest way to identify a mono or stereo TRS connector.
The mono version will only transmit a single-channel signal via the tip.
What Does a 3.5mm Mini-Jack Do?
The mini-jack is used for transmitting uncompressed analog mono or stereo PCM audio signals.
It does not support surround sound – unless used in multiple pairs like the sound card example above – or digital audio signals like Dolby Digital and DTS.
When Should You use a Mini Stereo Connection?
A mini stereo jack is often used as an alternative analog stereo connector to the more common phono connector.
This is because the digital audio connections support a wider range of audio formats – including surround sound.
However, where it is provided, a mini-jack connection is often your only way of hearing the audio – like the headphone out on your mobile phone – but it may also make sending audio to other devices easier.
It is also common to find different analog stereo connections on the back of a TV.
What Else Can You Tell Me About a Mini-Jack?
You will find this type of analog stereo connection on many consumer devices.
It is more likely to be found on small devices with limited space and is also very common as the line-level output on computer sound cards and monitors.
It is also commonly used for connecting headphones.
This connection type can be known by a number of different names:
- headphone plug
- 3.5mm jack
- 1/8 inch jack
- mini-stereo plug
- mini-TRS jack
‘TRS’ stands for Tip, Ring, Sleeve, and this refers to the design of the connector and the way the cable is connected to it.
TRS is a standard design for different types of analog audio connectors.
How to Connect a 3.5mm Mini-Jack to Stereo RCA
Sometimes it is necessary to change the connection type when wiring devices together.
So, if you have a device with a 3.5mm mini-jack output and want to connect this to a stereo phono input, what can you do?
This is actually a simple solution.
All you need is a 3.5mm to stereo RCA cable like this:
- Available sizes: 4, 8, 15 and 25-feet
- Connects smartphone, tablet or music player to an amplifier
- Gold-plated connectors
You might need a cable like this when connecting a TV’s analog output to an amplifier.
Or you could use this cable to connect the headphone output of a mobile device to an amplifier.
This can be a quick and easy way of getting sound from your phone, tablet or laptop to a speaker system.
A cable like this is also bi-directional – meaning you can also use it to connect a stereo RCA output to a 3.5mm analog input – like a PC’s audio input, for example.
So, essentially, it is an RCA to 3.5mm cable, too – it just depends on which way round you send the audio.
Just make sure that you buy the correct length for the job.
How to Connect a 3.5mm Jack to Coaxial or Optical Digital Audio
The previous example showed how to connect two analog audio connections.
However, what if your device has a 3.5mm jack output, but you need to connect this to a digital audio input?
If so, you need to buy an analog to digital audio converter box, like this:
- Supports uncompressed 2-channel PCM/LPCM stereo audio
- Converts to S/PDIF coaxial or TOSLINK optical audio
- Sampling rate: 48 kHz
- Not bi-directional - analog to digital only.
This adapter will accept a stereo PCM audio signal and output it as coaxial or optical audio.
This unit only has a stereo RCA input, so if your device has a 3.5mm output, you will need a 3.5mm to stereo RCA cable as described above.
Or, if you already have a mini-jack male-to-male cable, you could buy a different adapter that comes with stereo RCA and 3.5mm inputs, like this:
The main thing to remember with both these devices is that they only support an analog to digital conversion – meaning they won’t convert the audio from digital to analog.
How to Connect a 3.5mm Jack to a 6.35mm (1/4 inch) Jack
Another useful adapter for a 3.5mm jack is a 6.35mm jack converter – a 6.35mm jack is commonly known as a 1/4 inch jack.
An adapter like this comes with a female 3.5mm connector and a male 1/4 inch jack connector, like this:
- 6.35mm (1/4 inch) Male to 3.5mm (1/8 inch) Female
- For headphones and devices with small jack connectors
- Solid brass copper
The most common use for an adapter like this is to allow you to connect your headphones to the headphone socket of an amplifier.
You won’t need this if your headphones already have a 6.35mm jack, however many headphones these days come with the smaller 3.5mm jack connector.
This is because many phones and mobile devices use a 3.5mm connection.
But, if you want to connect your headphones to an amplifier or AV receiver, then these use the larger 1/4 inch jack as standard for the headphone socket.
All you need to do is put the 3.5mm male connector into the female port of the adapter – and you can then plug the 6.35mm jack into the headphone socket of your amplifier.
Just make sure that you buy an adapter that supports a stereo connection for headphones. You will know this by the two black rings on the barrel, which allow the separation of the stereo audio signal.
Take a look at the pictures further up the page if you are unsure what a mono and stereo connector looks like.
How to Connect an Apple Lightning Device to 3.5mm Headphones
The trusty 3.5mm headphone has been a feature on most portable devices over the years.
However, Apple changed this when they began releasing newer products without a dedicated headphone connection.
The idea was everybody should switch to wireless earbuds.
While this was a popular change with many people – the convenience of a wireless connection can be great when you are on the move – others found that they now couldn’t use their preferred headphones with a 3.5mm jack connector.
But, as ever, there is always a trusty adapter that can solve this problem.
If you are in this situation, you need to buy a Lightning to 3.5mm adapter cable, like this:
- Connect your 3.5mm connector headphones to your Apple device
- Works with compatible iPod, iPad and iPhone
- iOS 10 and later only
All you need to do is connect the adapter to the Lightning port on your Apple device, and then you can plug your headphones into the 3.5mm female port.
You can also use an adapter like this to quickly transfer music from your phone to a speaker system.
You will just need an extra cable to connect from the 3.5mm port into your amplifier’s aux input.
The 3.5mm to stereo RCA cable mentioned above will usually work, but you should check the input connections on your amp first.
Please be aware that this cable will only work with devices with a Lightning connector and iOS 10 or later.
How to Connect Your USB-C Device to 3.5mm
The previous section covered converting a Lightning port to a 3.5mm connection, but only for Apple devices
But, following on from Apple’s decision to remove the humble headphone socket, this is now more common on other devices, too – especially Android phones and tablets.
In this case, these devices will usually have a USB-C connector – rather than Lightning.
Therefore, if you want to connect 3.5mm headphones or cables to your USB-C device, you need a different adapter.
This USB-C to 3.5mm adapter is a popular choice on Amazon:
- No software required - plug and play
- Works with headphone controls for volume, track selection and calls
- Supported audio resolution up to 24/96
- Controls on Apple headphones won't work
Simply connect the adapter to the USB-C connector on your device, and you will have a female 3.5mm port available to plug in a cable or headphones.
The manufacturer mentions that using this cable will retain full use of your connected headphones – including pause, skip, volume and calls (except for Apple headphones).
Of course, you can also use this adapter with any device with a USB-C port, including PCs, laptops, tablets, and various game consoles.
If it has USB-C, it should work.
Remember, you aren’t restricted to connecting headphones. You can plug in a 3.5mm cable and send the audio to a compatible amplifier or speaker system.
What Is a 3.5mm to XLR Cable For?
An XLR connector isn’t widespread in home theater.
XLR connections send balanced audio signals, mainly in professional audio equipment like mixing desks.
However, some high-end AV receivers and powered monitors do have XLR inputs, and so you may come across this connection type from time to time in your home theater.
If so, why might you want a 3.5mm to XLR cable?
You would want one of these for directly connecting the stereo audio output of a consumer device – like a mobile phone, tablet, laptop or media player – into the XLR inputs of your amplifier or powered speakers.
A popular 1/8 inch TRS to XLR cable is this one on Amazon:
- Splits unbalanced 1/8 inch TRS to left and right XLR
- Oxygen-free copper conductors
- Copper-braided shielding
- Professional-quality construction
This particular cable comes in three different lengths and splits the unbalanced stereo signal into two male XLR connectors for the left and right audio.
You can also get similar cables with a single XLR connector, and these will sum the stereo signal and deliver a mono audio signal into your sound system.
About Home Cinema Guide
Paul started the Home Cinema Guide to help less-experienced users get the most out of today's audio-visual technology. He has worked as a sound, lighting and audio-visual engineer for around 20 years. At home, he has spent more time than is probably healthy installing, configuring, testing, de-rigging, fixing, tweaking, re-installing again (and sometimes using) various pieces of hi-fi and home cinema equipment. You can find out more here.