Author: Roderick
The history of headphones
Released in 2012, the Denon AH-D7100 (link to product page) was the manufacturer's flagship model, priced at around 1300 euros. Just 10 years ago, only a few headphones this expensive were on the market. The D7100 and the more affordable D600 were the first Denon headphones made with a biodynamic driver, whose drivers were not manufactured by Foster (Fostex). Many felt that the D7100 did not reach the same level as its predecessors, the older D5000 and D7000. The D7100 model ultimately did not find its audience and was not manufactured for very long.
When these headphones were still being manufactured, I was just starting my own headphone hobby – 1300 euro headphone models were far beyond my budget. Years later, however, I found a D7100 in truly terrible condition on eBay, which was affordable due to its state.
The headphones did not come with a cable or ear pads. The paint finish was badly damaged, the lacquer on the wooden parts was worn and dented, and there was hardly any of the faux leather coating left on the headband. The headband also had almost no clamping force left. Technically, however, the headphones were intact, apart from a contact fault that caused the sound to cut out intermittently on one side.
Restoration
I had heard a rumor that the AH-D600 model was essentially the same headphone as the D7100. When I came across an affordable and well-preserved pair of headphones, I decided to buy them to see if I could use parts to restore the D7100 flagship model. Fortunately, all parts of the D600 model were indeed exactly the same size as in the D7100 model – even the drivers are identical.
Disassembling the headphones was a fairly simple process. Only the metal logo on the cups had to be pried off using force. This inevitably caused small scratches, as the headphones are clearly not designed to be disassembled. Unfortunately, the part had to be removed because the headband is attached to the cups with screws located under the logo.
The visible parts of the wooden cups were in such poor condition that I tried to restore them to their former glory. I sanded off the lacquer finish, which worked quite well. However, since I didn't have lacquer of the exact same shade, the result was not satisfactory. I ended up sanding off the old lacquer completely and re-treating the wood. I brushed a mahogany-toned lacquer onto the wood surface, and after it dried, I added two layers of clear lacquer spray.
After the lacquer dried, I assembled the headphones using the D600 model headband. The D600's cable and ear pads also remained on the headphones. The operation was quite simple overall, but time-consuming, as I did the cup sanding entirely by hand without power tools.
Conclusion
Sonically, the assembled headphones should be identical to the original D7100, as the acoustics of the headphones are completely unchanged. The ear pads also appeared identical, with the exception of the color of the thread used for stitching.
Aesthetically, I think the end result was quite successful. The slightly amber-toned lacquer leaves more wood grain visible compared to the original coating. I eventually sold the refurbished headphones, which I've regretted a bit afterwards, as my building projects usually don't turn out this well.
Here are some more pictures of the end result:
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FI
This was great content, although probably not many people can just copy this building project like that 🙂
But it gives inspiration to tinker yourself and also some slightly different headphone content!
Great work!
Thanks for the feedback! Nice to hear that even slightly different content has readers 🙂 There's a sequel coming to that story, where 25-year-old Audio-Technica ATH-W10VTG headphones will be revived using drivers left over from the Denon project.
These restorations really have something special 🙂
Could be good content, e.g., DIY Cables for different headphones, balanced or not
DIY cables would indeed be an interesting topic, but I must admit that I have never made cables myself. Perhaps at some point, I'll delve into that too 🙂 The next DIY story is, in my opinion, more interesting than this Denon story, because with the Audio-Technica, I also had to adjust the structure of the headphones in different ways to get the sound quality right.
Interesting article. Repairing headphones is quite a difficult world. I have the cup parts of Focal One S headphones lying in a dresser, waiting for a better tomorrow, as the headband broke. I switched from them to Focal Listen headphones, which are almost identical in sound, but the headband is much better implemented. It's nice to see that sometimes manufacturers learn from their mistakes. It would still be nice to get those One S headphones working someday, but the matter is only complicated by the fact that their original structure is so poor that using similar new parts wouldn't provide comfort for long.
Focal's first models indeed seemed to have weak headbands as a common fault. Nowadays, things have generally gone in a worse direction regarding headphone repairability. For old Beyers and Sennheisers, you could always get, and probably still can, affordable spare parts that almost anyone can replace.