It got sold :( Oh well, I'll probably find one eventually. Is there any was to see what series driver they have without actually opening them up?
Need help finding a driver for a pair of KOSS PRO 4AAA - Page 2
If your earphones was not repaired, in original, we can see the 3 types of Koss 4aa.
1. This one has series 1 drivers. St has label with large letter "K"
2. Next has 1-2-3 series drivers in random order. On the label you can see little pictogram with headphones.
3. This one - is new model with series 4 drivers. It has lack of chrome on caps.
Saying about 4aaa, I must admit, that there is no differences between 1-2 series models
But, model "Plus" or 4AAA made in black colour, has 3-4 series drivers only
Also, vinyl ribbon on headband is very rare thing and I don't know where you can found it!
Edited by DkossZoSo - 11/3/12 at 7:42am
Please, look at this.
I cleaned of dust speaker of the second series. The membrane is the same as in the first series. Shape and density of membrane is the same. But magnetic system is different. I do not see how it is implemented. I think in the second series, the magnet is inside the whole core. In the first series the magnet and the core are both in the frame. Coils are the same - 252 OHM.
Also the picture clearly shows that the core of the second series is larger.
Reflex holes in both series are the same. The idea of damping is the same, but the damper is different. On the first series it is made of foam, the second is made of rubber. Damper pressed nut has differences. On the first series the nut is screwed into the core. In the second series the nut is putted on top of the core.
But sound is the same!!!