[Deep Funk]

Will do...

 

[Zombie_X]

Yo guys,
 
I have the K501, previously tdockweiler's, as well as a K400 which is still his. I was surprised by how the vintage K501 performed compared to today's models. It's quite musical and also rather neutral. I think it's right up there with the HD600 in terms of performance and sound quality.It's like a K702 but without the odd coloration. The soundstage is pretty massive and similar to the HD800's. Quite an enjoyable sounding headphone.
 
The K400 is something special. It's quite warm and very musical. Acoustic guitars sound exceptional on this headphone and voices also sound realistic. Quite wow'ed thus far. It really performs really good for it's age and still compares to the HD600 quite favorably. It has great dynamics, nice extension, and the soundstage is just plain great. I have been using these for the past few hours and I'm really liking the forward mids.

 

[MDR30]

K400 driver:
 

 
 
K500 driver:
 

 
They are slightly different, see post #225 for details.
 
I simply cut out pieces of gaffer's tape and covered half of the openings (white) in the baffle . I don't think it made much difference with the openings along the rim as these are covered by the plastic disc of the pads anyway, but overall the effect was very evident.
 
The mids became smoother and less muddy, and detail resolution better. The bass might have become clerarer, but the change wasn't radical. Sound stage is now more delineated and less reverberant, I prefer it.
 
I advise any owner of the K400 and K500 to try this simple mod, you may find it an improvement. Of course this is just an adaption of the three different baffles of the K501series, discussed here:
http://www.head-fi.org/t/227052/official-akg-k501-version-count
 

 
I also tried a "tape" version of the plastic dome cap supplied with some versions of the K500 (above and below), but did not find it to my liking (damping treble too much).
 

 

 

[tdogzthmn]

What i'm starting to take away from the K400 is that lets me hear the music more than my other headphones like the HD800 which make me hear more of little pieces but fails to present the big picture in a manner which is less audibly engaging than the K400.  Other factors like source and amp will of corse alter this perception, however there is a core truth in the DNA of this headphone which connects mentally to me in a special way.
 
But im sure others have the same experience as my own.

 

[rhythmdevils]

I think the technical term for that is "AKG Magic" 

 

[RexAeterna]

What i'm starting to take away from the K400 is that lets me hear the music more than my other headphones like the HD800 which make me hear more of little pieces but fails to present the big picture in a manner which is less audibly engaging than the K400.  Other factors like source and amp will of corse alter this perception, however there is a core truth in the DNA of this headphone which connects mentally to me in a special way.

But im sure others have the same experience as my own.

i get the same way with my 240DF hooked up to the speaker outputs of my Yamaha M-45 power amp and using my echo audio interface as a passive preamp. it just does something special adding type of realism. i know there is better ''technically'' headphones out there but some reason they never offer the same magic the 240DF does on my set-up.

 

[tdogzthmn]

I have a K240DF and K241 which I expect to arrive sometime next week.  I've been very interested in this can for some time and finally had the opportunity to snatch one from Deep Funk.  It will be interesting to see which of the two has more detail.  My K500 is having troubles with the right channel which goes dead from time to time, I was able to jump start it by cranking the volume to max.  Somehow that woke up the right channel but I probably have to reacable it avoid any further problems.

 

[Deep Funk]

Enjoy them. "To snatch" is a bit of an exaggeration isn't it? Anyhow, you now have two DFs and the K241 and I am happy they have good home now...

 

[boba6]

I take apart mine for recable and didn't watched whitch was the positive pin, damn
can anybody tell me? the upper or the lower pin? (if the pins are on the right side)

 

[MDR30]

Quote:

I take apart mine for recable and didn't watched whitch was the positive pin, damn
can anybody tell me? the upper or the lower pin? (if the pins are on the right side)

I assume you are referring to the K400? I don't have photos of the K400, but of the K401 which should have similar internal connections:
 

 
white = ground
yellow = left channel
red = right channel
 
TRS:
 
tip = left channel
ring = right channel
sleeve = ground

 

[MDR30]

Double post.

 

[boba6]

yes, the K400
but it has two pins on the right above each other, and the phone already tooke apart

 

[MDR30]

OK Mr boba6,
I'm not sure if you've already fixed it or taken your K400 apart, but I decided to open my K400 and take some photos for science and other Head-Fiers in distress.
 
The original cable of the K400/K500 had four leads:
 
transparent/white = left channel
red = right channel
black = left channel ground
black = right channel ground
 
 
http://www.akg.com/mediendatenbank2/psfile/datei/93/K501_K500_4055d21891b68.pdf
 
So here goes, first the left cup with the single-entry cable. Left+ is white/transparent cable in circle. The other one is ground. Note connections through headband steel wires to right side cup.
 

 
 
And here's the other side. Right+ is red cable in circle. The other one is ground.
 

 
AKG later changed these clip-ons to solder connections to avoid the intermittancy problem the early versions suffered from.
 
Hope you can fix your headphones and enjoy the classic AKG sound!

 

[boba6]

thank you very much! this is exactly what I needed!
so you recommend to solder directly the new cable and don't use these clip-ons, right?
regards
Balázs

 

[MDR30]

  I, own both the K500 and K400.  A visual inspection shows that the baffles are the same design between the two versions I own.  The drivers however, are different with the variation between the material of the diaphragm, and the etched ridges on the outer ring of the diaphragm.  These effects certainly cause an effect of the sound which to me translates to better clarity, speed, and neutrality on the K500.  The K400 on the other hand sounds warmer and more mids heavy and reduced upper frequency.

 

  K400 driver:
 

 
 
K500 driver:
 

 

 
tdogzthmn was right - there is a difference between the drivers I wasn't observant enough to notice. There are three major differences: the K400 driver has around 60 major ridges, with minor inbetween-ridges on the periphery of the diaphragm (a total of 120 ridges). The surface is shiny. The K500 driver has around 70 major ridges, with minor inbetween-ridges on the inner side (close to the coil) of the diaphragm (a total of 140 ridges). The surface is half-matte.
 
Some of these observations have been made earlier, but not in detail regarding respective model in the K400, K401 and K500 series. Mr Fitz has certainly made some points on the subject.
 
The K501 has a totally different kind of ridge, and only 24 of it:
 

 
The matte K601 (picture) and very similar K701 have no ridges:
 

 
Just like the DT880 of 1980, Lisztian warts and all:
 

 
 
(As an aside, I find the DT880 and K601 & 701 have similar sibilance/high midrange issues, maybe beacuse they lack the controlling ridges and suffer breakups, but the undamped peaks might improve transient response).
 
I'm not sure my findings are important but I find them very interesting. Acoustical engineers could probably explain the advantages and disadvantages of the K400, K500 and K501 driver designs, like the difference between an Otto or Wanckel engine, but the fascinating thing is that each could have its own virtues, detectable by a sensitive ear listening to good recordings with high quality ancillary equipment.
 
My favourite is the K500 with the baffle mod described earlier in this thread. What I discovered by a simple pressure test is that the K500 (and to some extent the others in the series) has quite a stiff ridge area, and a softer dome. Many modern designs have much softer and thinner diaphragms (less stiffness and less mass), sometimes with a stiffer dome. They are often more sensitive and bassier, but also less accurate (more distortion). See Tyll's distortion measurements of many so-called upper-class headphones!
 
My thesis is that the stiff diaphragm gives the K500 a better transient response (quick and with better control) and a tight bass with less distortion, It's not very sensitive and the dynamics are probably somewhat softened. It's a balanced set of compromises that appeal to my musical ear. This beauty sings well:
 

 
It would be very interesting if Tyll and Purrin could measure these old AKG models!
 
Thanks to tdogzthmn for making me think.