Lol... There's still some confusion, but we're getting closer now to clarity!

Quote Originally Posted by Barry View Post
The first of the Pro 4 range were the Pro 4 (https://www.ebay.co.uk/i/17433286654...yABEgKXxPD_BwE).
Cool... Didn't even know they existed!

The second version (and presumably improved) were the Pro 4A (with one 'A'). The third version were the Pro 4AA (with two 'A's), and the fourth and final version were the Pro 4AAA (with three 'A's). Since they are a development of the Pro 4AAs, one would assume they have an improved comfort and performance.
That is also clear, although the last bit, which I've highlighted, is debatable.

Firstly, it's not automatically guaranteed that the latest incarnations of any form of audio equipment are the best or superior to earlier ones, simply because costs are often cut (in a drive to increase profits) often at the expense of quality, build and/or sound. Therefore, it's dangerous having a mindset of 'latest is best'.

Also, are the PRO 4AAA (with three As) you're referring to the same as shown in this ebay ad, which I linked to earlier (the current production variety): https://www.ebay.co.uk/i/37306151053...RoCGpcQAvD_BwE or an earlier version of such?

My view is that the current ones above ARE inferior to all previous versions, and are likely made in China. It certainly sounds like it!

My Pro 4AAs look exactly like yours...
Do you mean these: https://www.ebay.co.uk/itm/Headphone...72.m2749.l2649

Just need to nail that one dead!

...because this suggests they are different:

and a solid and inflexible head band.
Because the headband on mine, whilst 'solid', isn't inflexible.

Those shown in the ebay link have a different, and IMO preferable, colour, which might have been a later colour change by Koss. They look to be NOS (the seller appears to be a trader who buys up old stock, and the one he has for sale is his last), and not copies.
Again, just to clarify, exactly which ones (either show a picture or provide a link) are you referring to?

Marco.