The DIY forum sees a lot of the same questions repeated frequently. This article is meant to consolidate and table some of the information people can use.
(You can edit this article or PM me with recommendations, corrections, suggestions, or questions. Just keep in mind that I'm a cable-builder newbie, myself, so I probably won't be able to provide technical support or make detailed equipment recommendations. -- ardgedee)
  1. Intro
  2. Connectors
  3. Wires
  4. Tools
  5. Resources


Things I could use help with for this section:
  1. Wiring information about headphone-side connectors.
  2. List of phones using Sennheiser connectors. I know I'm missing a couple.
  3. Ultrasone connectors? Beyerdynamic connectors? Some models have socketed cables. I think. I'm drawing a blank.
  4. LOD/line adaptor configurations for non-Apple products.
  5. Fact-checking connector configurations. I think I got everything right, but I'd hate for somebody to read this and then cross-wire a high-voltage electrostatic...
  6. A master list of which connectors are used on which custom IEMs. This is probably a tall order - currently new models are sprouting like mushrooms after a cloudburst. Most seem to use the Westone/JH type connector, but not all of 'em.
(See also: Intro, Connectors, Wires, Tools, Resources )
This section is broken into three parts:
Amp connectors
Headphone connectors
Other connectors
Almost every plug and socket listed below is also used in different wiring configurations for purposes unrelated to headphone audio. Do not depend on this chart if, for example, you're building microphone cables.

Headphone connectors, amplifier side

TypeWhere usedConfigurationNotes
2.5mm (3/32") stereo phone (TRS)Common on some mobile phones. Tip: Left signal
Ring: Right signal
Sleeve: Ground
2.5mm (3/32") stereo phone (TRRS) Balanced connector on Astell&Kern devices
Centrance GloveAudio A1
3.5mm (1/8") stereo phone (TRS)Standard stereo connector for headphones to small and portable devices Tip: Left signal
Ring: Right signal
Sleeve: Ground
Most popular stereo connector for headphones currently, ubiquitous in portable devices
3.5mm (1/8") stereo phone (TRRS)Standard stereo connector for headsets to mobile phones: iPhones and many other Apple iOS devices, recent Samsung, Blackberry, Nokia, and HTC Android phones. Tip: Left signal
Ring 1: Right signal
Ring 2: Ground
Sleeve: Microphone
Increasingly popular for mobile phones. Some headphone amps are compatible with this pin arrangement, others are not.
Ring 1 is closer to the Tip, Ring 2 is closer to the Sleeve.
Compared to the standard TRS connector, the ground is moved from Sleeve to Ring 2, and the Sleeve is used for mic and control signals.
6.5mm (1/4") stereo phone (TRS)Standard stereo connector for full-sized headphones for use with desktop or console amplifiers Tip: Left signal
Ring: Right signal
Sleeve: Ground
Formerly the most popular stereo connector for headphones, still common for home systems
3-pin XLRUsed in pairs for balanced console/desktop amps One connector for each channel:
Pin 1: Chassis ground (cable shield)
Pin 2: Channel positive (+)
Pin 3: Channel negative (-)
Shell: ?
The pins are numbered on the bodies of the plug and socket.
4-pin XLRUsed singly for balanced console/desktop amps Pin 1: Left positive (+)
Pin 2: Left negative (-)
Pin 3: Right positive (+)
Pin 4: Right negative (-)
Shell: ?
The pins are numbered on the bodies of the plug and socket.
There is no official pinout standard, but this is the normal arrangement for the cables shipped with AKG K1000 and HiFiMAN orthodynamic headphones.
4-pin mini-XLRUsed occasionally for line extensions Pin 1: Left positive (+)
Pin 2: Left negative (-)
Pin 3: Right positive (+)
Pin 4: Right negative (-)
Shell: ?
The pins are numbered on the bodies of the plug and socket.
There is no official pinout standard; convention is to replicate the full-size 4-pin XLR.
Auto-IRISBalanced connector on RSA balanced amplifiers Pin 1: Left positive (+)
Pin 2: Right positive (+)
Pin 3: Left negative (-)
Pin 4: Right negative (-)
Used for the Ray Samuels Audio balanced portable amps: The Protector and SR-71B. As such, frequently referred to as an RSA balanced plug.
Also used for the ALO Rx MK3 B balanced amp.
Also used for Centrance GloveAudio A1 and HiFi M8 portable amplifiers.
When connecting for MMCX connector for Shure IEMs (see below) + equates to signal and - to ground.
Outside of audio, this is commonly used to connect controller circuits for video camera lenses.
HIROSE HR10A-7R-6 Balanced connector on iBasso balanced amplifiers
HIROSE HR10A-7R-6P is the male connector
HIROSE HR10A-7R-6S is the female connector
Pin 1: Right ground
Pin 2: Right positive (+)
Pin 3: Right negative (-)
Pin 4: Left ground
Pin 5: Left Positive (+)
Pin 6: Left negative (-)
Pins 1 & 4 are not used for headphones.
Pins 1 & 4 are used only for device interconnects (eg, DAC -> amp)
Outside of audio, this is commonly used as a video connector.
Stax low-bias 6-pin for non-Pro products.
Plug is 86-71-6S [size=inherit](Cooper Interconnects, formerly Amphenol). [/size]Plug cap is a separate item. See datasheet available from Allied Electronics product page for info.
(Kevin Gilmore demonstrates that the Cooper/WPI/Amphenol connector is a near-match to the Stax plug, not an exact match)
[size=inherit]Socket is 78-S6S.[/size]
Pin 1: Bias
Pin 2: Right positive (+) (Front stator)
Pin 3: Left Positive (+) (Front stator)
Pin 4: Left negative (-) (Back stator)
Pin 5: Right negative (-) (Back stator)
Pin 6: Bias
High-bias Stax headphones are similar, except for the bias configuration.
Source and diagram: Wikiphonia
Stax high-bias 5-pin [size=inherit]The 6-pin plug (86-71-6S) with the center (#6 pin) removed, or the 6-pin socket (78-S6S) with center pin filled.[/size]
Pin 1: Bias
Pin 2: Right positive (+) (Front stator)
Pin 3: Left Positive (+) (Front stator)
Pin 4: Left negative (-) (Back stator)
Pin 5: Right negative (-) (Back stator)
Modified version of low-bias Stax connector. High-bias headphones can connect to low-bias drivers, but not vice versa.
Source and diagram: Wikiphonia
The following connectors are obscure, little-used, or obsolete.
3.5mm (1/8") stereo phone (TRRS)Rare: Used by HiFiMAN as a headphone connector for its HM-801 Balanced Amp Module. Also with the Sony ZX2. T: Left+
R: Right +
R: Left -
S: Right -
This uses a conventional connector in a nonconventional way, so be wary about randomly
plugging things in.
Koss electrostatic connectorUsed only by the Koss ESP/950 headphone and companion E/90 amplifier. Pin 1: Right negative (-) (Back stator)
Pin 2: Left negative (-) (Back stator)
Pin 3: Right positive (+) (Front stator)
Pin 4: Bias
Pin 5: Left Positive (+) (Front stator)
Some users build adaptors to connect the ESP/950 to high bias Stax-compatible drivers, due to the similar voltages (Koss: 600 V; Stax: 580 V).
Source, diagram and commentary: Wikiphonia
3-pin XLRRare: Used singly for unbalanced console/desktop amps, eg the Yamamoto HA-02 One connector for both channels.
No connection standard: Check documentation for the device you're hooking up.
The pins are numbered on the bodies of the plug and socket.
The primary advantage over a TRS phone plug is the minimized potential to short circuit when the plug is not fully inserted.
5-pin "Domino" (DIN 45620)Obsolete: used for a while in the 1960s-1970s on equipment manufactured in Europe.Building an adaptor is discussed in Philips Electret N6325 and "Domino" DIN outputUnless preserving the original equipment intact is a requirement, most recommendations are to snip the DIN plug off and attach a common phone or XLR connector.

Headphone connectors, headphone side

TypeWhere usedConfigurationNotes
Sennheiser 2-pin style
HD 600, HD 650, HD 25-1 II, HD25sp, HD580 Large Pin: Ground
Small Pin: Signal
Proprietary to Sennheiser. Note the HD25-1 II have a single sided cable. The pins will fit in other headphones, but the cable will be lopsided.
Sennheiser 2-pin style IEMIE80 Proprietary to Sennheiser
Sennheiser HD 800 styleHD 800 Proprietary to Sennheiser
Sennheiser cablesAny other Sennheiser Too many proprietary connectors to list on this, so here they are on ebay.
SMCHiFiMAN orthodynamic headphones; HE-5, HE-6, HE-500...  Miniature video connector, common in some parts of the world (but not the US)

Some vendors confuse female and male designations.
3-pin Mini-XLR AKG K702
AKG Q701
AKG K240
AKG K141
AKG K271
Pin 1: Ground
Pin 2: Right
Pin 3: Left
4-pin Mini-XLRAudeze LCD-2 Pin 1: Channel +
Pin 2: Channel -
Pin 3: Channel -
Pin 4: Channel +
2.5mm (3/32”) stereo phono with keyed housingShure SRH 840  
Threaded 3.5mmUltrasoneTRS 
Ultimate Ears Triple.Fi 10 connector UE TF 10
UE Super.Fi 5
UE Super.Fi 3
Left Front Pin: Channel +
Left Rear Pin: Channel -
Right Front Pin: Channel -
Right Rear Pin: Channel +
There is concern regarding the extent to which plugs for different IEM manufacturers look similar but vary in measurement. See the "Westone/UE Style Connectors" table, below.
Connector appears similar to common cIEM connectors but has a shroud or boot partially covering the pins.
The left channel of UE universal models is wired differently from the custom IEM models below. See this unofficial diagram of pinouts posted to the DIY Cable Gallery thread.
Custom IEM connectorJerry Harvey (JH), Ultimate Ears customs, Westone, Unique Melody, Heir Audio... Left Front Pin: Channel -
Left Rear Pin: Channel +
Right Front Pin: Channel -
Right Rear Pin: Channel +
There is concern regarding the extent to which plugs for different IEM manufacturers look similar but vary in measurement. See the "Westone/UE Style Connectors" table, below.
The left channel of UE universal models (above) is wired differently from custom IEM models. See this unofficial diagram of pinouts posted to the DIY Cable Gallery thread.
MMCX connector Shure SE846
Shure SE535
Shure SE425
Shure SE315
Shell: Ground
Pin: Signal
Illustrated in this exploded diagram of the Shure SE215
When connecting to Auto-IRIS (as above) ground equates to - and signal equates to + .

Westone/UE Style Connectors

 DIY set 1DIY set 2Heir Audio 4.A cableUE Super.Fi 3Westone ES 5
L front pin dia0.69mm0.68mm0.76mm0.74mm0.77mm
L rear pin dia0.69mm0.69mm0.77mm0.74mm0.77mm
R front pin dia0.69mm0.69mm0.77mm0.74mm0.77mm
R rear pin dia0.68mm0.69mm0.76mm0.74mm0.77mm
L front pin length3.02mm3.04mm3.32mmn/an/a
L rear pin length3.02mm3.04mm3.32mmn/an/a
R front pin length3.02mm3.05mm3.33mmn/an/a
R rear pin length3.02mm3.05mm3.33mmn/an/a
L gap between pins1.23mm1.25mmn/a1.05mm1.04mm
R gap between pins1.21mm1.20mm0.97mm1.04mm1.08mm
The 3rd party DIY plugs in the above table are plain plug housings with pins in them, for sale to DIY cable builders. On my samples (sold by tygamehk09 on Ebay), there was plastic mould flashing that had to be cut away from around the pins before they could be measured or tested. When soldering, note there's no notch or socket on the working surface, which might make a secure joint a little challenging.
The sockets on my left Heir 4.A are splayed, as are the pins, so I can't make a reliable measurement of the gap between pins. Regarding pin depth: I'm unable to measure the pin length on the UE SF 3 because the plastic boot on the plug interferes with the calipers, and I forgot to take this measurement in the brief time I had with the ES 5.
I briefly experimented with plugging the tygamehk09 plugs into both the Heir 4.A and UE SF 3. The plugs slide into and out of the Heir 4.A easily and seem stable once inserted. There's a little more resistance when plugging into and removing the SF 3. In both cases, the plugs do not require greater force than their original-equipment cables require. Keep this in mind when comparing figures in the table above.

Other Connectors

TypeWhere usedConfigurationNotes
Apple iOS device dock The iOS dock connector is multi-purpose, and can be used for analog in/out and data in/out, as well as power and other signals.
This table will only address the line-out dock (LOD), which is used to send a 2-3 V audio signal to an external amplifier.
For older iPods:
Pins 1 or 2: Ground
Pin 3: Right signal
Pin 4: Left signal
Universal iOS device LOD:
Pins 1 or 2: Ground
Pin 3: Right signal
Pin 4: Left signal
Bridge Pin 11 & Pin 15
Connect 68kOhm resistor from Pin 21 to Pin 11/15 bridge
There are at least two possible LOD configurations: A simpler construction for older iPods, and a more complex construction compatible with all iOS hardware
Photos and description of a universal iOS LOD
A comprehensive pinout list on
USB type B connectorCarries either or both digital signal and a low power line.  


(See also: Intro, Connectors, Wires, Tools, Resources )

Colors to indicate current:

Red and black are commonly used to indicate positive/negative (or signal/ground) on terminals such as speaker hookups.
  1. Red: signal or positive (+) leg.
  2. Black: ground or negative (-) leg.
Some cable manufacturers use other coding (patterns, translucency, or other colors), particularly for cables with more than two wires. Read the documentation.

Colors to indicate channel:

Red and black are also commonly used to indicate left/right channels in a stereo arrangement.
  1. Red: Right channel.
  2. Black: Left channel.
Left is also sometimes indicated with white, blue or yellow. In a three or five channel home theater system, cables for the center and subwoofer will often be indicated with green or blue.
ETP/TPC: This is the most common copper in all of electronics. It is universal for electrical applications. ETP has a minimum conductivity rating of 100% IACS and is required to be 99.9% pure. It has 0.02% to 0.04% oxygen content (typical). Most ETP sold today will meet or exceed the 101% IACS specification. As with OF copper, silver (Ag) content is counted as copper (Cu) for purity purposes.
OFC: Most common type of audio wire. This is a 99.99%pure copper with 0.0005% oxygen content. It achieves a minimum 101% IACS conductivity rating. Oxygen-free copper is produced by the direct conversion of selected refined cathodes and castings under carefully controlled conditions to prevent contamination of the pure oxygen-free metal during processing.
UP-OCC: Ohno Continuous cast copper boasting a single crystal per strand. Often seen in top teir audiophile cables, there is no scientific evidence support or refuting claims that this wire bring all around benefits to the gear paired with it. Carries no IACS conductivity rating or standard.


(See also: Intro, Connectors, Wires, Tools, Resources )
The list of good tools you could use are manifold. Instead of making specific equipment recommendations, let's stick to a rundown of what's available and sort by priority. Each item can have links to threads elsewhere in which people discuss their preferred products, and why.
Equipment guides for electronics beginners Things you must have Things you should have Things that are nice to have

Equipment guides for beginners

It probably isn't surprising that people have strong opinions about what you should start with. Below is some good general-purpose reading about how to set up your electronics workbench/table/desk...
  1. Getting Started in Audio DIY - in fact, this site is a rich resource of good information. Bookmark it.

Must have

The following tools are mandatory for building cables.
Soldering iron There are a broad variety of irons available for all kinds of purposes. If you have the budget, get a good-quality workstation unit with adjustable temperature. If you don’t, get a pencil iron in the 20-30 Watt range.
Also get a holder for the iron, so you can rest it while it heats up.
See the Getting Started in Audio DIY site linked above for a good analysis of what to look for and why.
PliersHave a couple pliers in a couple different sizes: At least one needle-nose and one blunt-nose. There are times you might be using both to bend something or pull it apart. 
WirecuttersFor occasional work, the wirecutter built into many pliers is sufficient. I also have an end nipper (where the cutting surface is parallel to the pliers’ pivot axis) which has been good for snipping wires as close as possible to the surface of soldering tabs. 
Wire stripperFor cutting and removing the insulation from the end of a wire.In a pinch, you can use a knife to cut the insulation and pull off with pliers (or your fingernail), but if you’re preparing a lot of wires, or the insulation is stubborn, this will get tiresome quickly.
ScrewdriversA variety of small sizes, both Philips and flat blades.Should go without saying, but you never know.
Helping handsThis is a tee-shaped stand made of steel rod, with articulated arms and alligator clips at either end. It’s essential for holding steady the things you’re soldering. The magnifying glass that many helping hands include can be useful too.Spending well can buy you an incredibly sturdy, highly reliable one, but the cheapest units are often reasonably stable. The magnifying glass on the cheapest units is sometimes uselessly bad, however.
Continuity testerFor testing that your assembly works as intended, before attaching it to equipment that might be damaged by cross-wiring or short circuits. This can be done with something as simple as a battery, small bulb, and some wire.For convenience, you'll probably eventually want to get a multimeter, discussed below.
KnifeFor slicing things, improvising as a wirestripper, cutting shrinkwrap and housings to size, or opening stubborn plastic packaging. 
Solder suckerThis is usually an aluminum cylinder with a plastic tip and spring-loaded pump inside. Melt a bad solder joint with your iron, get the tip close, and trigger the pump to draw out the solder. This cools the solder instantly and it can be ejected as a metal slug. If your work will always be perfect, you'll never need one. So you should get one.
This is best used in combination with desoldering braid (see consumables list, below).
Tip cleanerCommercially available tip cleaners are usually either small square sponges or balls of copper wool. A damp cotton or wool (but not synthetic!) rag will probably do, too. The purpose is to wipe excess solder off the iron to prevent drips and messes. A friend advises me to, instead, flick the iron away from you while you work. Probably not recommended if you're working over carpeting, in an open space, where food is stored, around other people...
Come to think of it, just get a tip cleaner.
The following consumables are mandatory for any soldering work.
Solder Make sure the solder is designated as being for electronics work. The cheapest available is usually 60/40, meaning 60% tin, 40% lead. Lead solder is banned in many parts of the world. Lead-free solder (with a little silver in it) and silver solder (with more silver) is increasingly common, even in areas where lead solder is still legal and available.
Solder size matters: If the solder wire is too fat, it becomes difficult to avoid melting too much into the joint. If the solder wire is too thin, it can be hard to get enough solder in to make a reliable joint. 0.032” (0.8mm) seems to be an acceptable general-purpose size for cable building.
Flux is also necessary but most solders include some. See the entry on Flux in the should-have table, below, for more info.
See the entry on solder in the should-have table for the difference between eutectic and non-eutectic solders.
Desoldering braidThis is a metallic braid for wicking away solder from a joint: Put the braid over the joint, press the soldering iron against the joint, and it will draw up the solder.For larger (or messier) solder joints, it is best to use the solder sucker first to eliminate most of the excess, and then apply the braid to clean up the rest.

Should have

These are some tools and consumables that will make cable-building easier, or help you make better cables.
Eutectic solder Leaded eutectic solder (most commonly 63% tin, 37% lead) works and is only slightly more expensive than the cheapest (60/40 tin/lead); a worthwhile upgrade if lead use in electronics is not banned where you are, and you're willing to use it.
Silver eutectic solder is available through Cardas, but is a proprietary formula and comparatively costly. Other manufacturers seem to only produce for the industrial market.
Eutectic solders are liquid when molten, solid when not, effectively nothing in between. A non-eutectic solder goes through an intermediate soft state while it cools; since there's a period of time where the joint is easily moved but the solder is unable to reflow into the space, there's a higher risk of making flawed joints.
Since eutectic solders go straight from liquid to solid without a mushy middle, it is easier to make reliable joints.
FluxFlux cleans the surfaces to be soldered and helps the solder flow over them. Most solder wire has flux in it, but prepping surfaces with flux before soldering avoids the chicken-and-egg problem of getting solder into a joint at the same time as the flux.See Steve Eddy's comment on flux in this thread.
MultimeterA meter with probes or alligator clips can be more convenient to use for continuity testing than a simple lightbulb circuit tester. Cheap ones can go for as little as $5 and be good enough as glorified continuity testers. If you expand your hobby into building full-fledged electronics (or if you will be building cables to specified impedance or resistance values), a multimeter will be necessary. 
WorklightA nice extremely bright desktop work lamp. You'd be amazed how much it helps. 
Fume extractorFor drawing the soldering smoke out of the air, improving workplace safety. The smoke and odor are primarily from the rosin, but trace amounts of metals can also evaporate as gas.Also sold as a smoke absorber or exhaust hood. Benchtop units are as small as 25cm (10.25") on the long side.
Heat shrinkThis may  provide a more robust (and neater) finish where cables are joined or where cables and connectors meet. Heat shrink is applied before completed connections and shrunk to size using hot air (ideally a hot air gun or powerful hairdryer).

Nice to have

These are things that make cable-building more pleasant and safer. If you're building cables frequently, these will move upward into the should-have list.
Better soldering iron When you budget for a higher-quality model you get something that is more comfortable to use, heats up faster, has a broader variety of operating temperatures (and stays where you set it), and has interchangeable tips.
Quality used irons are usually available on the usual auction sites, if you’re willing to risk the possibility of losing money on a dud.
No, really, whatever you have, there's a better one. It's true for your headphones, right? It's going to be true for your soldering iron too.
Magnifying glassThese are available as accessories to a helping hands stand, or as standalone gadgets that stand on top of or clamp to your workbench. Some have built-in lights, as an added bonus.There are tabletop magnifying glasses sold as reader's aids for the elderly, sometimes sold in housewares stores. In case you happen to be in such a store and are thinking about getting one.
List of Recommended brands and models:
Soldering Irons: Anything Hakko is decent. Weller makes good mid and high end irons. Low end irons from Weller, aren't that great, but will work with bulky cables.
Some recommendations
  1. Low:, Weller SP23L ($20)
  2. Mid: Hakko 936/937 (Old model, Ebay it) ($60~)
  3. High: Hakko Fx-888 ($100~)
Tool Suppliers:


(See also: Intro, Connectors, Wires, Tools, Resources )
Helpful sites: