[KOSS4LIFE]

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?

 

[KOSS4LIFE]

Also, do you know where I can get the black padded head strap? Pro4aaa models are rare, so it's not easy to get one.

 

[DkossZoSo]

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!

 

[KOSS4LIFE]

I have noticed the plastic pieces connecting the yolks to the ear cups are slightly different on some Pro4aaas. If you look at your pictrure it that last post and one before, you can see a difference.

 

[DkossZoSo]

Yes, you are right! I can see some differences. But, I had only two different models 4AAA's which I owned. So, I can not be shure in designating such specific differences.

 

[KOSS4LIFE]

I sadly only own one pro4aaa. But hopefully I can find a driver soon so I can put them to use. I also need to rewire mine. I might make the cord removable for easier storage for transportation. Then if it needed another cable replacement, it would be easy!

 

[DkossZoSo]

http://www.ebay.com/itm/VINTAGE-KOSS-PRO-4AAA-STEREO-HEADPHONES-FOR-PARTS-OR-REPAIR-/271099138866?pt=US_Headphones&hash=item3f1ec49332

 

[KOSS4LIFE]

Darn! I didn't see the post until today! Thanks for trying to help me, I really appreciate it.

 

[DkossZoSo]

Please, look at this.

[size=12.0pt]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 [/size][size=12.0pt][/size][size=12.0pt]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.[/size]

But sound is the same!!!

 

[KOSS4LIFE]

Strange. My second series driver is all white and has 4 tabs for mounting it to the Pro 4aaa. Sadly, Now my budget is extremely low, so it's unlikely that I will come across a first or second series driver to replace my broken second series driver.

 

[KOSS4LIFE]

 
This is the same series driver and headphones that I have. The left one is held on by the plastic, while the right driver is held on by 4 screws.

 

[DkossZoSo]

It is early sereis 2 driver.

 

[KOSS4LIFE]

Ok, good. I was told that the series 2 was only black and that confused me since the black and white drivers look the same.

 

[itza2mer]

I'm thinking of selling off some spare 4AAA drivers in near future, mainly series 1, some series 2. Never knew the 'series' thing before, know I know why some looked different, but sounded the same.

 

[KOSS4LIFE]

If you sell Series 2 drivers, I would be interested!