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May 5, 2015

Beyerdynamic Balanced Removable 4 Pin Mini XLR Mod

A client recently sent me one of my favorite headphones to modify, a Beyerdynamic DT770. The DT770, DT880, DT900, and similarly the T1, T5p, T70, and T90 are all intuitive to work with and respond well to new cables and mass loading.

Beyerdynamic DT770 - Pro 80 ohm version

This DT770 would be getting a removable cable mod, which includes the installation of a mini XLR in the headphone cup so the cable can easier be removed for transport or to perhaps have separate cables for portable and home use. The DT770 has room for a mini XLR jack on both the left and right cups, however this user preferred the simpler single ear input. Since I was already going through the trouble, I wired the headphone for balanced operation just in case he ever switches over to balanced listening in the future. The great thing about mini XLR jacks is they lock, so no need to worry about them slipping out like a 3.5mm or 2.5mm. Also, TRS connectors can loosen over time, however this is not as likely with the mini XLR connectors.

Below is a look at the interior driver. As you can see, the DT770 driver is unique in that it has a felt and plastic ring encircling the center, which reduces the sound wave reflection inside the cups.

DT770 driver and felt/plastic ring

Because the felt and plastic circle reach the plastic backing of the cups, any added mass damping should be clear of interaction. Below you'll note the Dynamat Xtreme installed is a small circle which is measured to fit neatly inside the cup and not cause any clearance issues with the driver. 

Dynamat Xtreme used as mass loading

Beyerdynamics used to come with a round hole, but it's square now that they've revised the manufacturing to some extent. I carefully increased the size of the hole diameter toward the round side of the cup with a Dremel to prevent the plug from getting in the way of the driver. The hole does not have to be absolutely round as the ridge on the mini XLR plugs will cover minor imperfections. 

Dremeled hole for 4 pin XLR mini jack

A three or four pin mini XLR jack can be used. In this case I used a four pin as I wanted the user to be able to upgrade to balanced down the line if he wanted, but in other cases, a three pin can be used as the ground is wired shared as default. Please note the position of the jack, if it is not close to the rounded edge like this is, the driver will not fit back in. Dremeling down the metal casing of the jack where it meets the driver may help a little bit, but will reduce the integrity of the jack if too much is taken off. 

Nice, clean fit

Wire should be run from one side of the headphone to the other as this is going to be single entry. A twisted pair of Zynsonix Xev silver clad wiring is prepped and sleeved with black polyolefin heatshrink tubing. 

Wire to run from one cup to the other

This can be wired however the user prefers, however I used the XLR standard (pin 1 = left +, pin 2 = left -, pin 3 = right +, pin 4 = right -). 

Wired with Zynsonix Xev silver clad wire

Before re-installation, the driver solder tabs are cleaned of the stock solder.

Solder tabs cleaned of original solder

The new Zynsonix Xev wires are installed using fresh Cardas silver content solder and the felt/plastic cups re-installed. 

Driver wired up and ready

The foam is reseated on top of the drivers and the earpads are reinstalled, so we have a nice clean 4 pin mini XLR input on our Beyerdynamic DT770 now. 

Installation of mini XLR jack complete

And finally we have the finished product featuring some cool colors, in this case rust with a black accent, terminated with a Switchcraft gold plated mini 3.5mm plug and a Neutrik / REAN mini XLR. Now these old Pros are ready for some stylish listening! 

I hope you enjoyed this post, please contact Zynsonix if you have a pair of Beyerdynamics (or any other headphone) that you'd like recabled or modified.

For more full-sized Beyer headphone mods, check out the Beyerdynamic T5p Recable and the DT880 Recable.

The Fine Print:
The above steps detailing the modification and re-cabling of a headphone 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.


  1. Why there is no photo of mini xlr installation into cup. I have an issue. Driver did not fit back into cup after mini xlr mount.

  2. Hi Serg, note from the images above that the connector is very close to the round edge of the cup, it will impede the driver from sliding back in place otherwise. Also, if you are dealing with a sealed Beyerdynamic Tesla headphone like a T1, T5p, etc., this mod is a bit too tight for my liking. Pigtails tend to be a better option.

    If you drilled the hole too far in, you'll have to dremel closer to the round edge until the driver fits, then fill the void with some speaker caulk. PartsExpress.com sells it cheaply.

  3. i did the same mod and i'm really satfied with it couple with a fiio q1 mII. The bass is really incredible now and clean.
    Add a velour/foeam pads from brainwaiz to contain the trebble and bring out the mid range for clearer voice and it's perfect.

    I too mistakinly drilled in the centre to make it look nice and run through the same problem Serg but i was far enough from the driver to make it fit.
    I'm amazed by the result. It's so good.

  4. hi can we mod DT 1770 PRo to balanced without any cutting or boring

  5. I personally haven't done the 1770 Pro but it looks like you'll need to remove the 3 pin mini XLR and replace with a 4 pin XLR similar to the AKG K702. With the K702 the mini XLR is affixed with adhesive, so it has to be ground out with a dremel before replacing.

  6. I have the Beyerdynamics DT 1990 PRO and I would like to have this mod done to them. Do you take on jobs or know a business that will do this mod?

  7. Yes, contact zynsonix.com for a quote. Best!

  8. quick question do you have a pin diagram showing which pin does what. that would be great and thanks for your help.

  9. Not currently. The pin numbers are visible on the plugs themselves. They can be wired however you like, however the industry standard is pin 1 = left +, pin 2 = left -, pin 3 = right +, pin 4 = right -