Alternative Title: Mythical Connectors and How to Wire Them
In this wonderful world of audio, there's a lot of devices. And a lot of them use different standards to link them together. But unfortunately, I have yet to see a single, unified resource that pools together every single audio wiring standard...
It's time to fix that. And also put my own opinions on each connector while I'm at it. It's my website, after all. #VivaLaPentaconn
If you see something missing or incorrect on this list, let me know and I'll fix it up as soon as I can.
By nerds, for nerds
Calling this a Frequently Asked Question section may be a bit of a misnomer. Nobody asked these questions frequently. Maybe once? I don't know. But I do think they were good questions, so I've included them here as a resource.
THE NUMBERS, MASON, WHAT DO THEY MEAN?
For circular connectors similar to 3.5mm, the convention is to refer to them from the top to the bottom; from the "tip" to the sleeve.
For example, a standard 3.5mm is "TRS". Tip, Ring, Sleeve. This means it has three contacts - the tip (the bulgy bit at the end), the sleeve (the bit just before the connector body), and one ring (in between the two). We count the contacts from the tip down around here.
For any other pin-based connectors, they're generally numbered - most XLR connectors have their pins numbered internally, which helps when wiring them up.
If a connector is marked as "+" and "-", that means it can be used in either left or right position without causing damage. If it states L+, it means that pin must be wired to the left-positive pin.
If you're here, then you're probably into DIY already, and this should make sense. If it doesn't, let me know and I'll update it!
IS SHIELD THE SAME AS GROUND?
Yes. Well, sometimes.
No, not really.
In single-ended headphones, most people refer to the shared negative signal wire as the common ground. This is, in fact, what I do too, though I don't think it's 100% correct to do so.
However, in balanced configurations, negative (denoted by "-") is the negative signal wire. In this situation, the shielding (usually a copper or metallic mesh surrounding the bundle of conductors) is optionally connected to the ground pin. Balanced lines don't require this for transmitting signal, but do depend on it for shielding purposes.
The ground is coupled to the chassis of the amplifier by the connector (XLR3, XLR4, etc), and is used in shielded cables to mitigate the impact of radio-frequency interference (RFI) and electromagnetic interference (EMI).
Though this isn't as important in high-current applications, such as headphone or speaker cables, shielding is absolutely essential in low-current situations. These include interconnects from your preamp or DAC to your headphone/power amplifier, or the cables that connect your turntable to the preamp.
In conclusion - all shields should be grounded, but not every verbal reference to ground is about the shielding.
The Standard Circular Minijack
This ubiquitous connector has been used and misused in many different ways, on many different headsets. Let's see how many different ways there are to use and abuse this standard.
This unbalanced connector can be found on many, many headphones.
MIC-ENABLED MINIJACK - OMTP
The OMTP standard, also known as the OMTP/Nokia is the mobile way of using a stereo headset with a microphone. If you don't have a microphone inline, just leave the pin disconnected.
If you're unsure which wiring scheme to use between OMTP and CTIA, use this one; it's much more common.
MIC-ENABLED MINIJACK - CTIA
The CTIA standard, also known as the CTIA/Apple is a mobile way of using a stereo headset with a microphone. If you don't have a microphone inline, just leave the pin disconnected.
CTIA is almost exclusively used with Apple products. Mostly iPhones and iPod Touch models.
Thankfully one of most common wiring standard is also the easiest. Wire the Tip to positive, and the ground to negative. This applies for both Left and Right - you need a separate cable running to both earcups for this!
HifiMan HE400i (new model)
Monoprice M1060 (new model)
The Audeze LCD-1 takes a unique spin on the standard 3-pole minijack. To get this one working, you need to wire the Left positive to the Tip, and the Right positive to the Ring. Essentially, it's a glorified headphone splitter.
The Oppo PM series of portable headphones use a four-pole minijack to allow for balanced connections. Or, single-ended from a normal cable. I think this is a pretty neat solution.
3.5MM TRRS COAXIAL DIGITAL
I won't pretend to fully understand FiiO's justification behind this pinout, but this is what it is.
My Favourite Round Connector
DUAL ENTRY 4-PIN MINI XLR
Personally, this is my favourite headphone connector to see on any reasonably-sized headphone.
I find it easier to bend the two pairs of pins together in order to solder them, rather than trying to bridge them with wire or solder.
Audeze LCD-2, LCD3, LCD-4
SINGLE ENTRY 4-PIN MINI XLR
Balanced connectors for single-entry headphones are best handled by the Mini XLR in my opinion. They are a tad fiddly though.
Most modded Beyerdynamics DT-series headphones
SINGLE-ENTRY 3-PIN MINI XLR
Beyerdynamic and AKG owners rejoice, here's a pinout for you!
My Least-Favourite Round Connector
2.5MM LOCKING (M50X)
I don't know what to call this one, but it's found on a few different headphones.
Sennheiser HD-518, HD-558, HD-598, etc
Audio Technica M40X, M50X, M70X, MSR7
2.5MM LOCKING (MOMENTUM)
The Momentum locking standard from Sennheiser is slightly flatter on top the the Audio Technica M50X one, and as a result, they are not compatible with one another. Bummer.
Sennheiser Momentum series
It's like a standard dual-entry minijack... but mini-er.
HifiMan HE400 (mid-old), HE350
Spooky Numberless Connectors
These are great to work with and feel amazingly sturdy, but all the ones I've worked with don't have any numbered markings on them. They do, however, have a keyed notch assembly, with a bulge on the pin part of the assembly. If you've seen these connectors in person, you'll know what I mean. I will refer to this mark as the "key".
Toward Key: +
Away from Key: -
I've only ever seen this chonkster deployed in the Focal Utopia. Absolute unit of a two-pin connector.
There are three official LEMO part numbers:
FGG.0B.302.KLAD52Z - Black finish
FGG.0B.302.CLAD52Z - Chrome finish
FGG.0B.302.NLAD52Z - Nickel finish
In-line with Key: G
Left of Key: L
Right of Key: R
Left and Right is relative to the soldering side, as looking down on the connector when the Key is pointing down.
This picture from LunaShops might help.
The Weird, the Wonderful and the Expensive...
These connectors are the ones I could only find used on a small handful of headsets.
4-PIN HIROSE (DUAL ENTRY)
Found on many Dan Clark Audio headphones, this connector was actually adopted from high-end lavaliere microphones.
The model number for this connector is HR10A-7P-4P(73). I know I've struggled to find the specific HiRose connector in the past.
Dan Clark Audio Aeon 2, Aeon X, Ether 2
MrSpeakers Alpha Dog, Aeon, Ether
4-PIN HIROSE - SINGLE ENTRY
Found on some of Dan Clark's older MrSpeakers headphones, this connector was actually adopted from high-end lavaliere microphones.
The model number for this connector is HR10A-7P-4P(73). This is a copy-paste from above. Don't @ me.
MrSpeakers Mad Dog
Small Pin: +
Large Pin: -
I believe this connector was designed by Cardas Audio. I like their solder.
Sennheiser HD265, HD525, HD535, HD545, HD565, HD580, HD58X, HD600, HD650, HD660S, HD6XX
Small Pin: -
Large Pin: +
I have no idea who designed this connector. I just like Fostex.
Fostex TH909, TH900, TH610, THX00
This connector board is used in a variety of headsets, some with and without full-blown condensor microphones in them. They're super neat, but for this pinout, I'm only including the driver connections.
Beyerdynamic DT150, DT250
Mostly found on IEMs, this coaxial aerial connector has been misused and bodged into a few commercial headphones too.
Monoprice M1060 (old model)
I really do like that these connectors screw-on, and lock into place. It's a shame they're just so bulky and clumsy. Not to mention hard to get inline versions.
Hifiman HE300, HE400, HE5, HE6 (old models)
3.5MM STANDARD MINIJACK
Many iFi portable headphone amplifiers use a four-pole minijack to allow for pseudo-balanced connections. Or, regular single-ended from a normal cable. I think this is a pretty neat solution.
If you've got a desktop amplifier, you've probably seen this before.
An up-and-coming new dog on the block, Pentaconn is a design being pushed by Sony. I am in full support of it!
4-POLE MINI XLR - RHA L1
Almost exclusively found on the L1 DACamp, RHA decided in their wisdom to break convention.
I am still annoyed by this.
A standard in balanced desktop audio. A sturdy and dependable friend.
DUAL 3-PIN XLR
Double the connectors, double the friendship.
Oh, and better isolation with truly separated grounds if you want to run shielded cables. Ideal for ultimate high-end headphones like the Abyss 1266.
Tiny balanced connector, found mostly on portable devices. Also found to be prone to snapping.
This one was standardised by Astell and Kern, so is sometimes referred to as "2.5mm AK"
High-Power Clips for the Loudest Klipsch
No, this isn't "speedcon" as I thought for a few years. It's an interesting high-power 4-pin connector though, and I would definitely love to see more things adopt it.
They go by many names - Banana connectors, Z-plugs, speaker bindings, 4mm connectors... However you call them, wherever you are... just solder the dang things. There's one pin! You can't do it wrong, can you?
Please note that while this list is correct to the best of my knowledge, it is only intended for guidance, and should not be taken as gospel. For wiring standards that will be compatible with your specific devices, please refer to the documentation provided by the original equipment manufacturer. If they have no official information publicised, try contacting them via email.
In conclusion, NLovell Audio takes no responsibility for any damage to person or property caused by cables or other creations that have been manufactured based on this publication.