[sullivanjay]

Hi, a friend of mine gave me a set of Koss Pro/4AAA headphones to repair. He tried to solder a loose / open connection and made a mess with splatter etc. When I got them three of the five wires in the input ear piece where not attached and he can’t tell me which wire goes where. Three wires from cable in and two from other ear piece. I thought it would be easy to figure where each wire goes but I’m not sure. There are two wires that go to other ear piece and which have not been disturbed in the ear piece. I think that there are two signal (channel) wires (red and white) and a common ground (black). Do I solder them as in the picture?

Thanks, Jay

 

[ericj]

Probably.

If the Pro4AAA is like my Pro4AA, the enraging part is that they didn't mark + and - on the drivers.

If they did mark + and - on the drivers, the tip on the headphone jack is left, the ring is right, and the sleeve is ground. You should be able to use an ohm meter to figure out the rest.

 

[sullivanjay]

All phono plugs have three wires just as you described. So my question would be is it OK to use a common ground? By the way, the speakers are not marked + and - and they are mounted 180 opposite each other. In other words + may be on the top of one speaker but on the bottom of the other. I believe this is important to keep them in phase. / J

 

[Arma]

Hi,

as You already opened Your Koss Pro/4AAA headphone I hope You can help me to access the defective soldering on the right side.
I already own the cushions replacements but I didn't find any screws under the original right cushion I had removed.
I'll gladly appreciate Your help.

At the following addresses You can find some photos of my headphone:

http://digidownload.libero.it/astrop.../Koss/1red.jpg
http://digidownload.libero.it/astrop.../Koss/2red.jpg
http://digidownload.libero.it/astrop.../Koss/3red.jpg
http://digidownload.libero.it/astrop.../Koss/4red.jpg
http://digidownload.libero.it/astrop.../Koss/5red.jpg
http://digidownload.libero.it/astrop.../Koss/6red.jpg
http://digidownload.libero.it/astrop.../Koss/7red.jpg
http://digidownload.libero.it/astrop.../Koss/8red.jpg

In 7red.jpg photo You can see the four holes that unfortunately don't show any screws.

Thank You and Best Regards
Armando

 

[itza2mer]

Arma, are you trying to figure out how to get access to the inside wiring to the drivers?

If so, the outside cups just snap into place. If I can get access to photos (I'll have to dig around) I have taken, it shows how to pry the outer cups out so you can get access to the driver wiring.

 

[itza2mer]

Right side earcup removal:

Left side, a bit trickier to remove. I used a very thin plastic card to help 'pry' the cup off:

 

[Arma]

Hi itza2mer,

Thank You very much!!!
Now my headphones (on both sides) sound as when my father bought them!

Thank You again and Best Regards from Italy!
Armando

 

[KolfMAKER]

I am currently working an the restoration of my own KOSS Pro 4/AAA headphones.

One of the things I need to do, is to replace the curled cable. It is damaged and broken on several points in the cable. And I was able to find a similar looking, vintage curled cable.

So, I opened up and removed the Left shell, and got access to where the cable comes inside and is connected.
I found out that the cable is 'locked' between the black housing and the metal ring. And that the metal ring must me loosened by 4 screws. At least ... I have seen on a Youtube video that they are 4 crosshead screws. But in my case they are bolts, and they lay sunken. So, it is hard to get tools around them and loosen them (see picture).

Question

• Does anyone know how to get the black casing loose from the metal ring, with these bolts?