Archive for April 2009

Repair: Rewiring your Sennheiser HD 280 Pro

2 years ago I, with much excitement, ordered a pair of Sennheiser HD 280 Pro’s. Both Gleb and Matt has a pair, and after listening to theirs… Apple’s little iPod buds just didn’t cut it anymore. I loved my pair so much that their connector ended up being severely bent when i squeezed past a, um, slightly oversized person sitting next to me in economy class on a flight back to South Africa. Anyways, the deed was done and the headphones became pretty much unusable, since only the one channel was getting through the bent pin!

I finally got around to rewiring them, which was more tricky than i expected! So here’s a post for others trying to do the same thing.

On stripping the connector, you discover 4 wires, rather than the expected 3:

First thing’s first, TIN THESE WIRES WITH SOME SOLDER! I had no idea that the copper strands themselves were covered by a thin film of resin, which needs to be burned off with some solder. If you try to connect an alligator clip straight to the bared wire, you get no connection, causing much confusion.

The 4 wire mystery was solved when I peeked into the left earphone. The two drivers are separately wired all the way to the connector. Two wires per channel = 4 wires. The mapping I discovered is as follows:

White – LEFT, GROUND
Black – LEFT, SIGNAL
Blue – RIGHT, GROUND
Red – RIGHT, SIGNAL

As follows:

If you’re interested, inside the left headphone there’s a little splitter board:

I bought a nice connector from Radioshack and wired this up. Be really careful when soldering the wires to the connector and don’t use too much heat! The shielding melts quickly and you don’t want your cable all melted together inside. I connected the two grounds from the two drivers together, which worked just fine.

After doing this, I was rewarded with a fantastic set of cans working again!