Headphone Connectors & Pins / Pinouts for DIY

So, as you have probably noticed, headphone manufacturers are not very good about standardizing connectors for use with headphones and amplifiers, to the point of absurdity. I am going to try and document most of the different headphone connector pin diagrams aka pinouts in one place so you don't have to pull out your hair tracking them down. If you need a cable built with any of the connectors below, reach out to Zynsonix Audio.

The 2.5mm TS with narrow shoulders originally was created for use with the Sennheiser HD700 headphone cups, but now has also been adopted for the Oppo PM-1, Oppo PM-2 and can potentially be used with the HiFiMan 400S, HE-560, HE-1000 and Edition X as the stock TRS does not use the ring (R). The tip is used for signal/positive, and the sleeve is ground/negative.

Recommendations: The best I've found are unbranded/generic connectors with the gold plated connector, chrome barrel and "long shoulders" which looks like the illustration above. I don't advise the other plastic/nickel plated plugs.

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The 2.5mm TRS is found on some mobile phones, although most use the ubiquitous 3.5mm TRS. The tip is left signal (L), the ring is right signal (R), and the sleeve is ground (G).

HiFiMan headphones (New Models): includes the updated HE400S and HE560, HE1000 and Edition X, which use this connector at the cups. Per measurements, the tip is the positive, the sleeve is the negative, and the ring doesn't appear to be used. 

Recommendations: As of right now, the best 2.5mm TRRS is made by Furutech, the FT-7254(R), but you'll pay for it at $35 a pop. Otherwise, Aliexpress is a good source if you purchase from a reputable vendor, and you can get fancy with carbon-fiber barrels, etc.

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The 2.5mm TRRS is commonly used for balanced operation for Astell and Kern portable digital audio players. Tip is right negative (R-), ring closest to tip is right positive (R+), ring closest to sleeve is left positive (L+) and sleeve is left negative (L-).

Other applications: 
Onkyo portable DP X1 DAC:  Tip is right negative (R-), ring closest to tip is right positive (R+), ring closest to sleeve is left positive (L+) and sleeve is left negative (L-).  : Source

Recommendations: 

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The HiFiMan HM-801 digital media player and Oppo PM-3 headphone (balanced) follow this unique configuration using the 2.5mm TRRS. Tip is left positive (+), ring closest to tip is right positive (+), ring closest to sleeve is left negative (L-) and sleeve is right negative (R-). Get yourself a nice aftermarket cable using the TRRS from Zynsonix Audio. 

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The 3.5mm connector (aka mini connector) is the most ubiquitous plug used for portable audio. The tip is left signal (L), the ring is right signal (R), and the sleeve is ground (G).

HiFiMan is now using 3.5mm plugs for some of their headphones as well like the HE-560 v3 just to keep us all on our toes. I have not tested a stock cable for the 560 v3, but using the tip for positive and connecting the ring and ground to negative works perfectly well. They're probably not using the ring like previous designs. 

Recommendations: There are tons of great options out there from Switchcraft, Canare, Oyaide, ViaBlue, Amphenol and more:

Amphenol K Series: Great value and there is an extended shaft version for use with phone cases.
Canare F12: Perfect if you are using thick cable thanks to the large barrel, but a bit heavy and may not fit some devices due to size.
Furutech FT-735 (R): I personally avoid this rhodium plated 3.5mm, the ground sleeve does not accept solder even at high temperatures in my experience and I had one where the tip broke off.
Neutrik REAN NYS231: Very slightly smaller than the Switchcraft, not as well made in my humble opinion, but low cost and works. If you have the scratch step up to the Amphenol K Series.
Oyaide: A bit overpriced in my opinion, but the long shaft version is one of the only connectors I know of that can fit Ultrasone headphones.
Switchcraft 35 HD series: A rugged, U.S. made plug, medium-sized and easy to use. The right angle version is very solid. If you order a ton of the right angle versions, be sure to test them before use... in rare cases you can run into a dud (in my experience).
ViaBlue T6s: If you're looking for audio jewelry, this will scratch your itch. The strain-relief system is a little awkward with set-screws and different-sized plastic rings, otherwise relatively easy to use. There are two sizes, small and regular. 

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The 3.5mm TRRS has quite a few applications:

iPhone and many other mobile phones: The tip is left signal (L), the ring closest to the tip is right signal (R), the ring closest to the sleeve is ground (G), and the sleeve is the microphone connection.

Oppo PM-3 headphones: This is used for the balanced cup connection for the Oppo PM-3. Per Oppo, the tip is L+, the ring closest to the tip is R+, the ring closest to the sleeve is L- and the sleeve is R-

Hifiman HM-901: Tip is L+, the ring closest to the tip is R+, the ring closest to the sleeve is L- and the sleeve is R-

Geek Out V2: Tip is L+, the ring closest to the tip is R+, the ring closest to the sleeve is L- and the sleeve is R-

Custom Red Wine Audio can feature this jack: RWAK240, RWAK380 and MZAK240

JH JH3A digital connection - Tip is left (L), ring closest to tip is right (R), the second ring handles digital coaxial information, and the sleeve is ground for both analog and digital.

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Leave it to Sony to come up with some weird format that confuses the market further ;) #Beta. To be honest I actually kinda like this connector. It's easier to work with than the teensy-tiny 2.5mm TRRS and less likely to break off in a jack due to the added girth. I still think the ideal connector should be locking with pins like a mini XLR versus spring tension like with this TRRRS, but since this is likely only going to be used with higher-end DAPs, the females have been of high quality so far and don't seem predisposed to failing over time.

I haven't seen the ground sleeve being used for anything yet, but from the tip, the connections are left signal positive (L+), left signal negative (L-), right signal positive (R+) and right signal negative (R-).

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The 1/4" TRS (aka 6.25mm TRS for the metric folks) is the most ubiquitous plug for home/studio headphones. The tip is left signal (L), the ring is right signal (R), and the sleeve is ground (G).

Recommendations: I find the Neutrik NP3C-BAG to be a great value 1/4" connector and the Furutech FP-704 (G) to be a great choice if you want to spend a few more dollars.  

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The mini XLR has become quite popular in the headphone market as it is relatively small, it locks in place, and the connections are more reliable than your average TRS. The mini XLR 3 pin is commonly used by AKG for their K-240S, K271 MKII, K701, K702. K712 and other K701 derivatives like the Quincy Jones Q701. The pins are labeled on nearly all mini XLR connectors, though you may have to look under a light to see them.

For the standard AKG wiring, pin 1 is ground, pin 2 is right signal and pin 3 is left signal. 

Recommendations: The tried and true is the Switchcraft TA-3, however I prefer the REAN RT3FC and RTCMC models at the same price as they seem a little more sturdy and have two different strain relief sizes depending on your wire size. The Furutech FT-610 resembles the Switchcraft, however has nicer rhodium plated connectors and looks a little prettier. Bottom line, if you want the best available, go with the Furutech, and if you need the best value, go with the REAN. 

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The standard-sized XLR is used for a few different applications. As an audio interconnect, Pin 1 is the ground, Pin 2 is the positive signal, and Pin 3 is the negative signal. You'll notice that most XLRs have the pins labeled 1, 2 and 3 if you look closely enough.

Recommendations: The Neutrik XX series is a great value. I also like the solid weight and feel of the Switchcraft AAA series, and they're two piece, so a little easier to assemble. If you'd like super solid and have a couple more bucks to spare, the Furutech FP series is a nice choice.

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Headroom initially debuted their first balanced headphone amplifier in a dual 3 pin configuration (I suppose if someone wanted to have headphone monoblocks in the future), however the 4 pin XLR proved to make more sense as it's an easier, less cumbersome implementation. You'll notice that most XLRs have the pins labeled if you look closely enough. Pin 1 is L+ (left positive), Pin 2 is L- (left negative), Pin 3 is R+ (right positive), Pin 4 is R- (right negative). Nearly all balanced headphone amps use this configuration, as well as the legendary AKG K1000. 

Recommendations: The same recommendations from the 3 pin XLRs are echoed here: Neutrik XX series is a great value. I also like the solid weight and feel of the Switchcraft AAA series, and they're two piece, so a little easier to assemble. Furutech also just released (FINALLY!) a 4 pin XLR, the FP-705 in 2016, which is a great choice for a few more dollars. 

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As mentioned above, Headroom initially debuted their first balanced headphone amplifier in a dual 3 pin configuration. It still sticks around today, however is not as popular as the 4 pin configuration. You'll notice that most XLRs have the pins labeled if you look closely enough. Pin 1 (typically the ground) is not used for balanced headphones. Pin 2 is used for the positive signal, and pin 3 is the negative signal. In this diagram, the white wire is left positive (+), the orange wire is left negative (-), the red wire is right positive (+), and the blue wire is right negative (-). 

Recommendations: The same recommendations from the 3 pin XLRs are echoed here: Neutrik XX series is a great value. I also like the solid weight and feel of the Switchcraft AAA series, and they're two piece, so a little easier to assemble.  If you'd like super solid and have a couple more bucks to spare, the Furutech FP series is a nice choice. Also the Cardas CG series is pure eye candy and a popular choice of my clients.

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The Kobiconn Auto IRIS is an odd little connector typically used with cameras. These are found on Ray Samuels (RSA) balanced portable headphone amplifiers like the Protector and SR-71B, however are also on amplifiers Centrance GloveAudio A1, HiFi M8, and the ALO Rx Mk3 B. Pin 1 is left positive (L+), pin 2 is right positive (R+), pin 3 is left negative (L-), and pin 4 is right negative (R-).

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The Male SMC connector is used to connect to older HiFiMan headphone cups, and current models such as the HE-6. As you can see from the pinout, the signal is the small center pin, and the ground is the textured area at the end of the connector. Care should be used when soldering the ground, as using too much solder will prevent the brass cover from sliding over.

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The Sennheiser HD connector features two pins. It's difficult to notice on a quick glance, but one is larger than the other. The larger pin should be used for ground/negative, and the smaller pin is signal/positive.

Recommendations: There are only a couple of DIY connectors out there that are compatible with the Sennheiser HD265, HD525, HD535, HD545, HD565, HD565 II, HD580, HD600 and the HD650. ... Cardas and Furutech, the Cardas HPSC and Furutech  FT-2PS.

The Cardas HPSC is reasonably priced ($~16 as of this writing), but not ideal for beginners. It's a flexible molded plastic with not much room for the wire to be soldered to the internal pins, and the rhodium needs to be heated enough so the solder takes, but not enough for the plug to melt. Flux can be helpful for this, and I personally fill the cavity with a plastic-like hardening adhesive for longevity. The Furutech FT-2PS runs quite a bit more (~$46 as of this writing, but makes the soldering much easier by separating the pins with plastic, features an internal clamp for strain relief, is made of tough plastic, and looks great. So personally, I would purchase the Furutech unless cost is an issue.

This is a work in progress and there are still a few connectors to add ;) 

The Fine Print: This page is for entertainment purposes only and is not intended to substitute or supercede what a manufacturer states or recommends for their product. Zynsonix Audio, LLC does not furnish any guarantee for the accuracy of information herein, and does not assume responsibility for damages sustained by entities referencing this information for any reason. 

Zynsonix guarantees all cable and headphone work performed by Zynsonix Audio, LLC to be correct, however does not guarantee the work of other entities, whether individuals or businesses, that make use of this information. 

AES EBU 110 Ohm Digital Cable

The very first real-time software MP3 player was a program called WinPlay3. This program was released way back in September of 1995, back in the days of half gig hard drives. As MP3s gained popularity and began to distract computer users from glorious MIDI music, Winamp from Nullsoft was released in 1997 and by the next year, Winamp in its various iterations was downloaded over 3 million times. Several years later, the first version of iTunes was released to the public in 2001. Fast forward to today, a little over a decade later, and computer audio has become very widely accepted and many audiophiles are more likely to fire up a PC than pop open a compact disc player.

The WinPlay3 Program

Because the CD player is going the way of the dodo (obsolescence), audiophiles choose to interface their PC with a DAC (digital audio converter) in order to extract the music in the best sounding way possible. A DAC requires a digital signal be carried from the PC to the external DAC. In some cases the PC has a direct output for a digital signal from the motherboard or sound card, in other cases, a user may choose to use a USB to SPDIF converter box, such as the M2tech HiFace or Musical Fidelity V-Link to name a few.

Digital signals can be carried a few different ways, either optically or via a coaxial cable. Many enthusiasts frown upon optical cables due to perceived jitter and myriad other issues, although I have found the glass ones to be acceptable in the past. Optical cables actually isolate the ground from one device to another which can be a benefit in the case of a dirty ground at the source. The other option, a coaxial cable with a single center conductor isolated with a dielectric and a return which is typically a copper mesh over the dielectric, can be terminated with either an RCA or BNC.  In the case of the AES/EBU, there is still the copper mesh over the dielectric and there are two conductors in the center.

Standard digital coaxial cables are preferred to be rated at 75 ohms, and since BNC connectors are legitimately 75 ohms, they are preferred, but in many cases BNC connectors are not offered and an RCA will suffice. If you are lucky and your PC output and DAC both have an AES/EBU jack, then you’ll have the best possible connection between your devices. AES/EBU coax cable should be rated at 110 ohms.

AES/EBU, also known as AES3, was developed by the Audio Engineering Society (AES) and the European Broadcasting Union (EBU) way before the first software MP3 player in 1985 (although revised in ’92 and ’03) and is effectively the professional version of S/PDIF. Much more additional information regarding the AES/EBU standard, including protocols, time slots and channel status bits can be found at http://en.wikiaudio.org/AES_EBU .

Musical Fidelity V-Link 192 featuring an AES EBU connection

Now that we covered what an AES/EBU is and where it came from, I’ll go ahead and assemble a nice audiophile quality one. One of the fortunate things about the AES/EBU protocol is that is calls for a standard XLR connector, of which there are many audiophile versions floating around, I’m sure some of which use time-corrected flux capacitors and pixie dust gathered during ancient times. I’ll personally be using the DHLabs Silver Sonic XLRs, which is a strange name as the contacts are gold-plated pure OFC copper (no brass!), but they’re great connectors for the dollar, and the DHLabs Silver Sonic D-110 110ohm coax cable, which has silver plated copper conductors within a PTFE dielectric, spacers for constant impedance and a 100% coverage shield.

Silver Sonic D-110 Cable and XLRs

First on the agenda is covering the wire with some nice sleeving. I selected the Techflex brand Carbon Reflex sleeving, which is a polyethylene terepthalate material braided with 3M Ultra reflective monofilament. In simple terms, the weave reflects light and looks pretty impressive.

As noted in the photo below, there are two insulated wires (positive and negative) and a drain wire which connects to the shield for the ground. Also in the center is the Silver Sonic XLR female pieces.

Sleeved with Carbon Reflex

...and here are the Silver Sonic XLR male pieces.

Silver Sonic XLR male connector

Although not necessary, I sleeved the drain wire with Teflon like the other two conductors for uniformity.

Drain wire with Teflon sleeve

These wires are soldered in place on each of the male and female connectors. The ground wire (the drain wire in this case) is soldered to pin 1, the positive wire (red in this case) is soldered to pin 2, and the negative wire (black in this case) is soldered to pin 3. Also note that with the Silver Sonic connectors, slipping the boot over the decorative sleeving requires some patience.

XLR Pin Diagram

Once everything is soldered in place, the barrels of  the DHlabs connectors are slid over the soldered connections and the three screws over each connector are replaced. The two screws over the boot in the back back a very substantial strain relief system. Below you will see the finished digital AES EBU cable. 

Finished digital AES EBU Cable

Hope you enjoyed reading this post. If you are interested in having your own custom digital AES EBU cable (or any other cable) made, please contact Zynsonix for a quote.


The Fine Print:
The above steps detailing the building of a cable are for entertainment purposes only, and not to be performed under any circumstances. The owner of this blog and all associated parties can not / will not be held responsible if you attempt the process posted and cause physical harm to yourself, your surroundings or your property. Please keep this in mind.