I've been doing some more research and from what I've found the 251 had both the shallow dish and the deep dish CK12s. Mid-1960 seems to be when the deep dish started to get used. The 251 I compared the 414 EB to, should have the deep dish because it is from 1961.
https://gearspace.com/board/showthread.php?p=14012532
Also, I haven't found any indication that AKG used the shallow dish CK12 in any of their later microphone models after the 251.
So, unless the 251 was made pre mid-1960 and sold in 1961, both it and the 414 EB should have the deep dish version of the capsule.
Nope…
All the
AKG-Telefunken ELA-M 250 &
AKG-Telefunken ELA-M 251 (
E and non
E) microphones had the
CK-12 Deep Dish Capsule and
T14/1 Output Transformer…
As you can see by the attached schematic all of these ELA-M’s (E and non E) were “officially” dated at
1961…
The
AKG – Siemens SM 204/3 was a Cathode Bias microphone like the
AKG-Telefunken ELA-M 250 &
AKG-Telefunken ELA-M 251 (
E and non
E) microphones, but from the other hand it has the
CK-12 Flat-Shallow Dish Capsule and the
Rohde & Schwarz V-2545 Output Transformer…
Also the
AKG – Siemens SM 204/3 had a different circuit than the
AKG-Telefunken ELA-M 250 &
AKG-Telefunken ELA-M 251 (
E and non
E) microphones had and it is more “close to” an
AKG C-24 Stereo Microphone circuit or to a
C-12 Microphone System circuit…
Your
AKG 414 EB microphone although it was produced back at
1976, it had by designer’s choice the
CK-12 Flat-Shallow Dish Capsule, because back in this time at the AKG AG they tried to re-produced the “vintage vibe” of the
50’s C-12 Microphone System, but this time used FETs…
If you want like it to see it in a synth "analogy", it was something like the Moog Voyager monosynth, as the Moog Co. tried to replicated with the Voyager the sound of the legendary Moog Minimoog with more modern features…
Now as I wrote you before if someone’s like to have a more extended range of the low end in the
AKG-Telefunken ELA-M 250E & AKG-Telefunken ELA-M 251E circuits and in the
AKG – Siemens SM 204/3 circuit with a
6072A / 12AY7 tube, he can easily use
2 Signal / Rectifier Diodes (0.6 Volts), wired them in Series and use them as
Cathode bias element in the place of the
1k8 Cathode Resistor…
He can either use a
ECC81 / 12AT7 tube with a
2k7 Cathode Resistor or just a
Red LED (1,6 Volt) as
Cathode bias element in the place of the
2k7 Cathode Resistor and then he will get again more extended range in the low end with the
ECC81 / 12AT7 tube…
In a more “advanced way” he can either wired the
ECC81 / 12AT7 tube “en parallèle” and then he can use just a
White LED (1 volt) as
Cathode bias element…
As you can see as DIY’er there are many more “tricks and tips” that someone’s can do today, than they couldn’t have been done by AKG AG, back in the times of ‘50’s and ‘60’s…
EDIT: The 251 in those two shootouts are the modern reissue by Telefunken USA. If it is from the early 2000s it might have an original CK12 in it, otherwise it would be a recreation.
Nope again…
The Telefunken Elektroakoustic USA ELA-M 251E microphone(s)
HAVE NOT any
original AKG AG “Brass” CK-12 capsule in them, as they nether they had or have…
Since they haven’t (as Telefunken Elektroakoustic USA) reviled who is the original manufacturer of the capsule, it may be a Chinese one…
