I recently purchased a pair of Beyerdynamic DT 770 headphones for the occasions when I need to wear some closed back headphones.
But, as someone who can’t just let things be, I decided to aggressively modify these already perfectly good enough headphones. Not because I wanted to get better sound from them (I have no way of knowing if these actually sound better than stock), not because any part of them were broken (I bought them brand new), but just because I could.
Quick overview of the modifications I made:
- Replaced the fixed cable with an input jack (a 3-pin XLR jack specifically), and recabled the connection to the second ear cup
- Replaced the plastic baffle with some cotton, because there wasn’t room to leave the original baffle with the input jack added
- Added a suspension strap for comfort
- Redesigned the ear cup yoke and adjustment
Replacing the input cable (aka the “cable mod”)
This is the most common mod you’ll probably see for any of the Beyerdynamic DT xx0 series headphones, because the stock cable is quite long and not fun to deal with.
Because it’s such a common mod, and because I didn’t document any of the process, I’m going to keep this section really short.
In a very broad overview, the process for replacing the cable with an input jack is:
- Desolder the cable from the drivers
- Remove the cable (and retaining clip) from the ear cup
- Using a rotary tool, widen the hole the cable originally went through so that it can fit a mini-XLR jack. I don’t think this step is necessary if you just replace the input with a 3.5mm jack.
- Solder some wires between the mini-XLR jack and the drivers
A key things to note, because the driver sits very closely to the front of the existing cable hole, I needed to make sure any material I removed to widen the hole was from the back of the ear cup.
Additionally, while you could just clip bits out of the original plastic baffle so that the new input jack and cables fit, and this is what I originally did, replacing the baffle with some cotton is easier, and based on some research I did can result in some better sounding bass.
Adding a suspension strap
The next modification I made to these headphones was swapping the large top padding with a suspension strap instead. This is entirely a personal comfort mod, along with maybe a slight aesthetic mod, because I prefer the way a suspension strap feels on my head.
I should note, that without the follow up mod of replacing the yokes with my custom designed ones, this change resulted in the adjustment yokes being very loose. While not a problem when listening, when they’re off your head the height adjustments change just from looking at the headphones.
To create the suspension strap, I bought some craft leather, cut out a 1.5 inch by 7 inch strip, drilled holes in the strip so that it could be attached the friction block (this also meant replacing the screws in the fiction block with larger ones so that the block could still screw together with the added depth of the strap)
The final modification of these headphones was swapping out the yoke/adjustment mechanism that came with them with my own design.
Unlike the other mods, I basically had to figure out how to do this from scratch, doing the design, fabrication, and assembly steps all myself. Because of this, it was both the most time consuming (waiting for 3d prints to finish) but also most interesting to me, because I learned how to design and print the new bits.
The new yoke assembly consists of four parts:
- The actual yoke, the Y like piece that clamps in to the earcups,
- Two pressure blocks, which are attached to the suspension strap and metal headband,
- A 70mm standoff, connected to the yoke and suspended between the pressure blocks. I did not create this part, and just ordered it (along with a bunch of M3 screws) online. If you’re trying to recreate this, you can just search for “M3 70mm stand off”.
While I created the models for these pieces from scratch, the design was heavily inspired by the adjustment mechanisms found in Audeze LCD and Grado headphones.
If you’re interested in making the suspension mod yourself, I’ve uploaded the STL files to thingiverse, at https://www.thingiverse.com/thing:4949606.
While only one of these modifications actually substantively changes how I use these headphones (the cable replacement mod), it was still fun to take them apart and build my own replacement parts. Would I do it again? Yes, absolutely, but for no reason other than it gave me a project to work on.