[DMax99]

Early production: headband not leather, all golden color plug, thinner cable

Later production: leather headband, part of the plug is black, thicker cable, drivers looks different as well.

I'm sure somewhere in this thread are pictures and more description of the differences.

Hmm... Dang it.. Mine had been recabled and the headband I'm not sure if it's been replaced or not... I'm pretty sure it's leather headband though

 

[tdogzthmn]

Guess I lucked out with my EP K400 then!

 

[MDR30]

There are at least three driver varieties in the K400. First it's the hole (bass loading) at the back of the driver, in the center.
 
Then it's the amount of filtered openings under the ridged part of the diaphragm.
 
I'll describe them here as best as I can. I've had seven or eight K400 pass my hands. But it should be said that AKG made changes during production so use it only as a guideline.
 
1. Large driver hole with foam. This foam has deteriorated in all phones I've seen, and should be changed to new foam (or tape with a small hole, or micropore - it's possible to tune the bass here in many ways). Twelve filtered openings, all metal plug. Driver connections close together on the same side, with a blue glue blob to fix one of the wires to the diaphragm (which can cause an annoying rattle).
 


 
 
2. Large driver hole but with rubber grommet to make it smaller. Four filtered openings. May be possible to remove the grommet, but I've never tried - looks pretty tightly locked [EDIT August 2014: it can be removed, with a pair of pliers and some force]. All metal plug. Driver connections close together on the same side, with a blue glue blob to fix one of the wires to the diaphragm (which can cause an annoying rattle).
 


 
 
3. Small driver hole. Four filtered openings. Metal/plastic plug and leather headband. Driver connections on opposite sides of the driver (see red rings), like later K701. No blue glue.
 



 
 
If you take off the pads and hold the headphone in strong light (sun, if weather permits) you can easily see if it has four or twelve filtered openings, and if it's a grommet/small hole version.
 
If the centre of the driver is dark it's most likely the foam version, which probably needs to have its foam changed.
 
Also enclose a pic so you can see the difference between the plastic and leather headband versions.
 

 

[DMax99]

Mine is the leather headband version

 

[MDR30]

 

 

 
 
From the original brochure. The first test I've read about was in a German hifi magazine in January 1991, so my guess would be that the new K400 & K500 were introduced in 1990 (maybe for Christmas sales).
 
The new AKG web site seems to omit the fine historical archive they used to offer, and in the company history profile no headphones are mentioned at all! Outrageous.
 
If I missed it, and somebody else found this type of information on their sites, chime in.

 

[vid]

I like how they admit the brochure to be a subjective spiel.

 

[DMax99]

Can anyone please explain to me the difference between k400 and k401?

Thanks!

 

[Tiemen]

Quote:

Can anyone please explain to me the difference between k400 and k401?

Thanks!

 
If I remember correctly, the K401 is (almost) indentical to a late production K400, both in looks and sound.
The headbandstrap  is not the leather one though.

 

[bracko]

Is $100 too expensive for a k400 with plastic headband?

 

[DMax99]

Is $100 too expensive for a k400 with plastic headband?

I think most of them go for 100+ now

 

[Tiemen]

In Europe they usually go for about 50,- Euro if they are in a good condition.

 

[bracko]

Quote:

In Europe they usually go for about 50,- Euro if they are in a good condition.

It is less than $100. 

 

[DMax99]

In Europe they usually go for about 50,- Euro if they are in a good condition.

Really? Where? That's excluding postage right? With postage included, are they still under 100USD?

 

[bracko]

Quote:

Really? Where? That's excluding postage right? With postage included, are they still under 100USD?

The ones that I am intending to buy are well used anf cost $120, postage included. I live in Europe. 

 

[DMax99]

The ones that I am intending to buy are well used anf cost $120, postage included. I live in Europe. 

That does sound quite expensive then. The one I got was from Germany, I paid about 60 bucks for it, but when I received it found out the cable was stuffed. So i got a partial refund which ended up to be about 30 something or 40 something bucks shipped.