The Marco-boy main system, as of August 2020

I'm not disputing the physical differences, only the terminology. Your link is for the Pro 4AA.

My Koss Pro 4AAs are most certainly original (they have a 'khaki geen colour and made in the US by Koss; I didn't know that 'replicas' were being made elsewhere. They must be illegitimate copies, as I can't understand why Koss would continue production of the 4AAs after introducing their replacement: the Pro 4AAAs.

If your Pro 4AAs are a copy, then it is possible the SQ is different (and inferior) to the original Koss design.


But all this is by the by: as I have said elsewhere, I'm not that keen on listening with headphones, but pleased you are pleased with your new 'phones. :)

Lol - we're still somewhat at cross purposes here...

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Originally Posted by Barry

I'm not disputing the physical differences, only the terminology. Your link is for the Pro 4AA.

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Let's clear this up, as I suspect said nomenclature is where the confusion lies.

It's my understanding. although I could be wrong, that the originals are called 'PRO4-AAA', as in 3 As, not 2, and indeed as per the ebay ad where I bought mine: https://www.ebay.co.uk/itm/Headphone...72.m2749.l2649

You'll see they are clearly marked as 'KOSS PRO 4AAA', so that's what I've always referred to as the originals. The modern 'replicas' are known as Koss PRO-4AA (2 As, not 3), as shown here: https://www.ebay.co.uk/i/37306151053...RoCGpcQAvD_BwE

And If you examine both headphones, you'll see that they are made quite differently. So which ones have you got (a pic would be good)?

Do they look like the originals I've bought, shown in the first link, or more like the modern versions, shown in the second link? And which model number do you consider denotes the originals: 'AAA' or 'AA'?

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If your Pro 4AAs are a copy, then it is possible the SQ is different (and inferior) to the original Koss design.

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It's not a case of just MINE being a copy (that is the modern replicas I owned before buying a pair of the originals), but ALL currently produced ones for sale, such as shown on the ad above - and yes as a result they DO sound inferior to the originals, massively so!:)

Marco.

The 4AA was introduced in 1970. The 4AAA was a couple of years later. So both are 'vintage' designs although it does appear that Koss are still making both models in the present day.

Whether the modern versions differ substantially from the vintage ones I don't know, but the confusion is understandable.

The first of the Pro 4 range were the Pro 4 (https://www.ebay.co.uk/i/17433286654...yABEgKXxPD_BwE). 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.

I cannot imagine Koss continuing to manufacture previous Pro 4 designs, once they were superseded by a later version.

My Pro 4AAs look exactly like yours, with a sage-green finish and a solid and inflexible head band. 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.

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

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Originally Posted by Barry

The first of the Pro 4 range were the Pro 4 (https://www.ebay.co.uk/i/17433286654...yABEgKXxPD_BwE).

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Cool... Didn't even know they existed!

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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.

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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!

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My Pro 4AAs look exactly like yours...

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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:

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and a solid and inflexible head band.

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Because the headband on mine, whilst 'solid', isn't inflexible.

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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.

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Again, just to clarify, exactly which ones (either show a picture or provide a link) are you referring to?

Marco.

The ebay link you provide is for a pair of Pro 4AAs (read the tile of the sale thread). I had assumed, despite the change in colour, they were genuine NOS stock.

Yet there does seem to be some evidence of a 'new' value-engineered version of the Pro 4AA headphones: (taken from the Audio Review site)

This review is for the "NEW" version of the Pro-4AA's that has been re-designed and is different from the "OLDER" version. First of all DO NOT waste your money on this new version of the Pro-4AA especially if you had the older version. They are made like Garbage!! Cheap plastic and cheap materials is what makes up this new version. I removed one of the ear pads,and there were 2 staples holding down the mesh pads to a piece of cheap felt!! I couldn't believe it!! The adjustable headband is made so poorly,it's a struggle just to adjust the size. And of course most importantly; The Sound. At 250-Ohms impedance they are difficult to drive, even with a Headphone Amp. I am a headphone enthusiast and use a well known high-end Headphone Amp; and they sound like total crap!! The old version was WAY better than these, all around. If you want to spend $100 get a pair of Sony MDR-7506,Sennheiser HD-280 or AKG K-240S which all will absolutely blow these away.

Maybe that is what is being sold on ebay. If it is, it is a shame Koss feel the need to apply cost-cutting measures to their former, well regarded, Pro 4AA design. Even if it is to 'cash in' on the reputation amongst studio users amongst others, the cheapened version will do Koss's reputation no favours at all.

My Pro 4AAs look exactly like the ones you show in the second photograph: sage green in colour, with a solid (but slightly flexible) headband having a foam rubber insert. I'm not at home at the moment so cannot take a photograph, so you will just have to trust me.

Your second ebay link(https://www.ebay.co.uk/itm/Headphone...72.m2749.l2649) is for the Koss Pro 4AAAs, which as you will see are the same as those shown in the first photograph of your post.


One other thing I dislike is on most Koss phones is the very heavy coiled lead. Unless supported, it tends to pull down the left hand side of the phones.


Anyway, I don't want to go around in circles - I'm going out to enjoy the Autumn sunshine and share Zen with my fellow man. It's going to rain later this evening and will do so for the next few days.

ATB

Lol - I don't want to round in circles either, just simply establish that we're talking about the same thing! So...

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Originally Posted by Barry

The ebay link you provide is for a pair of Pro 4AAs (read the tile of the sale thread). I had assumed, despite the change in colour, they were genuine NOS stock.

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Yes, if you're referring to this link: https://www.ebay.co.uk/i/37306151053...RoCGpcQAvD_BwE showing the modern production ones I've owned for 8 years.

But no, if you're referring to the NOS ones I recently bought on ebay, shown on the other link: https://www.ebay.co.uk/itm/Headphone...72.m2749.l2649

As you'll see, those were advertised as PRO-4AAA, which in actuality, I think is the wrong model number. Based on the historical order order of release you stated earlier, which I believe is correct, they're either PRO-4A or PRO-4AA. AAAs are shown in the first link, which are quite different in construction.

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Yet there does seem to be some evidence of a 'new' value-engineered version of the Pro 4AA headphones: (taken from the Audio Review site)

Maybe that is what is being sold on ebay. If it is, it is a shame Koss feel the need to apply cost-cutting measures to their former, well regarded, Pro 4AA design. Even if it is to 'cash in' on the reputation amongst studio users amongst others, the cheapened version will do Koss's reputation no favours at all.

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I can say as fact, as I bought some, that that is *exactly* what is being sold on ebay, shown in the first link above, and sound wise, they are significantly inferior to the NOS ones I bought shown in the second link.

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My Pro 4AAs look exactly like the ones you show in the second photograph: sage green in colour, with a solid (but slightly flexible) headband having a foam rubber insert. I'm not at home at the moment so cannot take a photograph, so you will just have to trust me.

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Lol, it's not about trusting you, of course I do, but rather about ensuring that we're taking about the same thing!:D

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One other thing I dislike is on most Koss phones is the very heavy coiled lead. Unless supported, it tends to pull down the left hand side of the phones.

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Not found that myself...but I'd prefer the lead to be longer. In reality, most people will not be sitting close enough to whatever the headphones are plugged into, for the stock lead to suffice. Another half metre or so would make all the difference!

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Anyway, I don't want to go around in circles - I'm going out to enjoy the Autumn sunshine and share Zen with my fellow man. It's going to rain later this evening and will do so for the next few days.

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Indeed, so enjoy!:cool:

Marco.

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Originally Posted by Macca

The 4AA was introduced in 1970.

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Ok, so when were the PRO-4, shown here introduced: https://www.ebay.co.uk/i/17433286654...yABEgKXxPD_BwE

And are the ones I bought, shown here: https://www.ebay.co.uk/itm/Headphone...72.m2749.l2649 PRO-4A or AA?

*That* is what I'm trying to ascertain. They're defo not AAAs, as those were introduced later and look quite different from Barry's or mine.

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The 4AAA was a couple of years later. So both are 'vintage' designs although it does appear that Koss are still making both models in the present
day.

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Firstly, what does the 4AAA of a couple of years later (1972-ish?) look like compared with the 4AAA currently being sold, as shown here: https://www.ebay.co.uk/i/37306151053...RoCGpcQAvD_BwE and why are those being sold as 'AA', not 'AAA'?

Secondly, Koss are only making the model shown in the link above, nothing else, so there is no "both".

Marco.

We know what the original PRO-4s look like, as Barry has provided a link. What's unclear, however, is what the A, AA and AAA look like in comparison, and so need some pictorial evidence of such!:)

Marco.

Pro4AAA came out in 1976. They look like the ones you bought off of eBay to me.

Koss own site has a full timeline of all their headphones and pictures of them too:

https://www.koss.com/history/

Should resolve all questions :)