Edited by vid - 6/25/12 at 3:42pm
Looks to me that those are what is sometimes called "Production Proto-Types".....An item that is put into very limited production to see how things go.....looks like AKG decided not to go full throttle on that model, pity, looks like it had some great potential.
In addition, AKG did not go all the way in promoting the K250, probably since they felt it would compromise the valuable penetration into the recording studio with their K240/K240DF line.....Being in the position of having many recording studios automatically say to them selves that the K240DF should be for sure included in their equipment options is not an easy things to do and accomplish at all.....That sort of penetration into a market is hard to get, and probably the K250 threatened that K240 penetration in recording studios. Just a hunch as to why the K250 was never promoted much....
I bought my first pair of Realistic Pro 50's off of ebay back in 2006 for $25. At the time, it was a complete unknown. I don't think it had ever been mentioned on Head-Fi. I only picked them up due to the physical resemblance to the older AKG headphones. After receiving them, seeing the "Made in Austria" label on the side quelled any doubts. I sent an email to AKG soon afterward. Here it is, as well as the reply that I received (with names removed). The AKG representative also attached the service documentation PDF for the K250, which is strangely absent from the AKG website. I converted the PDF to a jpeg image. I can upload the original somewhere if needed.
reply from AKG representative:
Notice the date of 1981 on the document.
It is certainly possible that the AKG representative is incorrect. But it is interesting that he used the phrase "original model K250" to describe the Pro 50, implying that the K250 had more than one iteration, similar to the way that the K240 Sextett Cardan eventually evolved into the later, easier to manufacture versions without the passive diaphragms. It would make sense that the K250 may have followed down the same path. There's also the possibility the Pro 50 is a unique AKG creation designed exclusively for Radio Shack's Realistic subsidiary. I never actually obtained a pair of K250's, so I have yet to do a side by side comparison, but the aesthetic similarities between the two models are hard to ignore.
Just for the record, I had no intention of misleading anyone in my past posts saying that the Pro 50 and K250 were the same.
There's some interesting information posted here, thanks all!
tyre, that K 250 service doc looks interesting; it's very strange that they haven't added it to the AKG product archive. There are two possible things the AKG rep may have meant by "original model K 250" I think. He could either be implying that there's an earlier K 250, or he was making a clear distinction between AKG's own (original) model and the one made for RadioShack. His wording is very ambigous, though. There are magazine ads (here, for instance) that seem to place the Realistic Pro 50's introduction to late 1979 – so an earlier K 250 would then have had to have been from the late 70s. If you could upload the service doc PDF somewhere so that the part names would be visible, that would be much appreciated (if you don't have a space for it, drop me a PM and I can upload it to mine). (I don't mean to imply that you or anyone else has intentionally misled people – although I do feel that the image of the Pro 50 baffle that you posted [here] could do without the number 250 in its filename. To be honest, the AKG rep was misleading you, if anything).
Deep Funk, I bought the Philips version of the K 260 some while ago, so maybe I can do some comparison between that and the K 250.
zeno, in the context of your prototype theory, would the fact that the K 250 contains no trace of the AKG logo mean anything? Since tyre's service doc has the date 1981, and if the K 240 Monitor/DF indeed spelled doom on the K 250, then maybe the early 1980s (and maybe the late 1970s?) were when the K 250 was around.
I'll update my first post with the K 250 service doc information later today.
It not having the logo is probably more of a general aesthetic choice than anything here....since there have been other AKG models that did not have any logos, and some that did and do. the AKG logo is also on the K250 box....The fact of the K250 model being so hard to find any evidence of it even on the AKG web site etc, is more of an indication that they did not go full throttle with it than not having a logo. Looks like the K250 not having any lgo was with keeping it's "spartan and "cleanliness" of it's over all design. To me it comes close to having a "Scandinavian" design.
Which AKG models didn't have the AKG logo on them? (I don't doubt you, I'm interested.) It's definitely very adventurous of AKG to drop their logo from the K 250 considering that all their other models at that time seem to have come with one. Although, as Fitz has said, AKG was very adventurous.
When I saw that the K 250 had no AKG logo on it anywhere, I suspected that it may have been due to the K 250 having been meant as a specialty phone of some sort (kinda like this K 141) for whatever context where a logo wasn't desired. I couldn't think of any such context, though. And, of course, the headband has "AKG" written on it with massive letters even if there is no logo as such.
The thing about the K 250's design that irks me is that the rectangular side panels (are those called sliders or what?) stand out too much. They look oversized – they look too much like they were simply taken off a K 340 and put on the K 250. On the K 340 the shape flows around the cups, but on the K 250 it connects to nothing. This, of course, is just subjective opinion on my part, and I don't know much about Scandinavian design.
Regarding the K 250 service manual, how reliable is the date on that exactly? I quickly looked up the service doc for the K 260, which had a date of 1993 on it – even though, according to http://20cheaddatebase.web.fc2.com/AKG/AKGindex.html, the K 260 were discontinued in 1989. So either that manual was updated years after the K 260 had been discontinued (possible, to reflect part availability or whatever), or that website isn't too reliable.
The first version of the K240 that came out in 1975 did not have the Logo on them.....
I should have mentioned that it was a higher resolution image. I enlarged it to twice the original size to better see details.
Another clue pointing towards the K250 having passive diaphragms at some point in the past is within the service document itself. Part number 11 - "diaphragm holder". Google translates "membranscheibe" to "membrane disc".