Repairing a pair of HD 205's

A friend of mine pushed a pair of broken HD 205's in my hand. When I inquired what's wrong with them, he stated that I should give them a listen. I promptly found out that the mids were completely gone - usually a result of faulty wiring. He then gave them to me for free, so naturally I couldn't refuse the challenge to try and fix them.

On to the workbench.

They look so innocent lying there on my workbench. Little did they know that they would be guttered within the next few minutes...

The left cup with the driver removed

Pads removed as well

I measured DC resistance across the drivers - ~31-33 ohms across both channels. This is fine.
Then I measured whether ground was rightly connected, which seemed to be the case.

'Must be the jack' I thought to myself and measured continuity between the two channels and the tip and ring of the jack, once again all fine. But then as expected the sleeve (ground on the jack) measured very high resistance between the ground pads in the left driver. Seems I found my culprit, and I swiftly went on to cut my way into the jack.

At then end of the wire I cut of the jack and stripped of the sleeving

After a difficult battle I was somehow able to remove the plastic surrounding the jack. Since I didn't have a new jack handy, I would just have to accept the fact that it's gonna look real ugly.

I soldered the wires on  as shown in this image.

I blobbed some more tin on all the wires and added a small heat shrink to the end of the cable sleeve to strengthen it.

It certainly wasn't easy to remove the plastic casing from the jack, and it took me a good ten minutes. After that I only needed to solder on the wires  with a good amount of solder. After I gobbled as much solder on the wires as I could fit, I heated the jack for some extended time to physically melt the plastic casing and mix it a bit with the solder. This smells terrible, but it does relieve some extra mechanical stress, which is definitely needed since the wire doesn't have any rigid support. 

I measured connectivity between the tip, ring and sleeve of the jack, and their respective channels and I was pleased to find 0.00Ohm on all three. All I needed to do at this point was to bind the jack in a meter of electric tape, screw the driver back on and test the thing.

As you can see the final result is quite ugly, but hey, I didn't have a new jack so this is pretty much the best anyone could do. Before I could test them however, I had to remove the little black rings on the jack since they expanded somehow by excessive heat. Having done this I tested them and they sounded like I expected (which is still not very good by the way).

Geen opmerkingen:

Een reactie plaatsen