Telefunken C12 User manual
1Diamond Series
2TELEFUNKEN Elektroakustik 3Diamond Series
What’s In The Box
M 910 Power Supply
Designed and built in America, the M 910 power supply features the
traditional stylings of the original Austrian-made AKG units partnered with the
improvements of modern component technology and circuit board design. A
notable dierence is that the modern M 910 has combined the power supply
and the pattern selector box into one unit for improved functionality and easier
transportation. These units are built well over-spec to ensure reliability and
safe operation for decades. Each power supply is calibrated to the specic
microphone system it comes with. They are burned in as a full system to ensure
optimum performance and stable operation.
The M 910 is fully regulated to ensure consistent operation regardless of line
voltage variations or location. The heater voltage circuit is designed to ramp up
to optimal voltage over 20 seconds, which helps to extend the life of the vacuum
tube. The M 910 features premium Neutrik connectors. While these connectors
are not historically accurate, they are considered a superior connector when
compared to the original Cannon and 5-pin DIN connectors.
M 810 Cable
The M 810 features a historically accurate swivel stand mount connector on
the microphone end and a premium Neutrik 7-pin XLR connector on the power
supply end. It is designed to mate with original C12 microphones and will power
vintage units that have been converted to self-bias operation. This cable is made
by TELEFUNKEN technicians in the USA using Sommer SC-Octave Tube cable,
which has been custom-designed for the connection of tube microphones.
Manufactured in Germany, SC-Octave Tube cable provides high quality, linear
transmission with high exibility and 100% interference rejection. 10 meters
(32.8 feet) in length.
M 751 Rycote Shock Mount
The Rycote InVision USM is the best shock mount currently produced, both for
functionality and isolation. Its unique, adjustable universal locking system can be
quickly adjusted to securely t a wide range of microphones. The USM utilizes
specially designed clips made from robust Hytrel thermoplastic, designed to
never sag or need rethreading. This indestructible, innovative design provides an
additional 12 dB of isolation compared to conventional elastic shock mounts.
FC10 Locking Flight Case
TELEFUNKEN Elektroakustik’s microphone ight cases are designed with
delicate capsules, vacuum tubes and electronic components in mind. A unique
blend of seven Wisconsin hardwoods is utilized in the construction of the shell,
while the outside of the case is wrapped in 1000pt Cordura, the world’s nest
traveling ber. Dual combination locks and trim in nickel create an understated,
classic look. An embroidered TELEFUNKEN diamond logo on the inside lid, and
engraved logo plate complete the package.
WB10 Wooden Microphone Box
Custom-made solid oak box. Vintage styled with classic TELEFUNKEN Diamond
logo. Made in America.
For a complete list of additional accessories and replacement parts for Diamond
Series products, please visit http://t-funk.com/shop
Shop Webstore
4TELEFUNKEN Elektroakustik 5Diamond Series
Handling
Handle your microphone, cable, and power supply with the utmost care.
Remember that Diamond Series microphones are reverse engineered from
vintage models, so most mechanical parts are custom machined and not
cheaply or easily replaceable. If damage occurs or there is a change in
Storage
When not in use, store your microphone in the included wooden box. It is not
recommended to leave your microphone on a stand. Not only will dust degrade
the response of the capsule over time, but this greatly increases the risk of a fall,
which could result in required mechanical repair or cosmetic damage.
Properly coil your tube microphone cable when storing. Kinks left in the cable
will expedite the deterioration of the conductors which will lead to shorts or
opens in crucial contacts, and ultimately failure.
Cleaning
To clean ngerprints and light grime from your microphone, wipe with a soft
cloth damp with an ammonia-based glass cleaner as soon as possible. We use
microber cloths, but any soft, lint-free cloth will do. Spray the cleaner onto the
cloth rst. Never spray any liquid directly onto your microphone.
To lubricate your threaded cable collar, apply a small amount of electronics
cleaner/lubricant (we use DeoxIT Gold) with a cotton swab. Do not spray the
lubricant directly into the cable connector.
Never attempt to clean your microphone capsule. This should only be
performed by a reputable, trusted professional. It is recommended to contact to
TELEFUNKEN to have this service performed.
If you have any questions regarding cleaning your microphone or having these
services performed by a TELEFUNKEN technician, please contact repairs@t-
funk.com.
Quick Start Guide
1. Thread the included shock mount or stand mount cable connector on
to a sturdy microphone stand. Double check that the stand is stable and
properly balanced; falls from microphone stands can require costly repairs. It
is recommended to use the shock mount stead of the stand mount to reduce
mechanical vibration from transferring to the audio path via the stand.
2. Set the microphone into the shock mount and tighten until hand tight.
3. Insert the cable into the base of the microphone and begin threading it on. If
you experience resistance, reverse the threading direction and make sure the
connector is inserted correctly.
4. Plug the other end of the microphone cable into the included power supply.
It is recommended that the power supply be at least 3 meters from the
microphone while recording. Make sure the cable is kept close to the stand and
ground to avoid tripping or knocking over the microphone.
5. Make sure the power supply is set to the correct mains voltage (115V or
230V). Plug the included power cable into the power supply, then into mains
power.
6. Connect a standard 3-pin microphone cable (not included) to the power
supply and then to your microphone preamplier input.
7. Turn on the power supply. Let the system warm up for 10 minutes before use.
Safety Warning
Vacuum tube microphones, their associated power supplies, and their cables
carry potentially harmful voltages. Make sure all connections are made before
powering on your microphone system. Do not open your microphone or power
supply while it’s connected to mains power and powered on. If for whatever
reason your Diamond Series microphone stops working, turn it o and contact
an authorized TELEFUNKEN repair center.
6TELEFUNKEN Elektroakustik 7Diamond Series
Diamond Series Overview
The Diamond Series features three primary microphone models that epitomize
vintage vacuum tube microphone technology, which characterize and color the
sounds of popular recorded music from the late 1940’s through today. These
three pillars of the vintage microphone world were selected to preserve their
legacy not only because of their extremely high delity sonic abilities, but also
because they exemplify the nearly gone culture of high quality manufacturing
and hand-made workmanship.
The Diamond Series currently comprises of ve microphones; three main models
and two variants. They are the C12, ELA M 251E, ELA M 251T, U47 and U48.
All of the parts for these microphones were reverse engineered and recreated
exactly to the originals in order to manufacture new models and provide
restoration parts for the vintage versions. The large majority of the parts are
custom tooled and machined in the USA, where TELEFUNKEN Elektroakustik is
located.
Every microphone is hand-built and assembled from the ground up and
tested in the TELEFUNKEN facility located in South Windsor, Connecticut.
Each microphone is individually wired point-to-point; no circuit boards to be
found here. Every plastic is riveted by hand, and each assembly is tapped
and screwed together by hand. Diamond Series microphones are produced in
smaller production runs to achieve the nest attention to detail.
The dream of TELEFUNKEN Elektroakustik remains to preserve these iconic
microphones and their history, and to develop new microphone technology that
draws inspiration from them. TELEFUNKEN continues the tradition of producing
high delity recording instruments to benet the recording and performing world,
and to continue to characterize music for generations to come.
Vacuum Tube Information
TELEFUNKEN 6072A
TELEFUNKEN Elektroakustik Diamond Series microphones feature vacuum
tubes specially selected to properly mate electronically and sonically with
each model. All tubes used are burned-in and tested for noise and gain prior
to installation in South Windsor, CT. TELEFUNKEN maintains a large stock
of vacuum tubes and replacements that have been tested specically for
microphone use are available directly.
Please visit www.t-funk.com/shop/vacuum-tubes for more information.
This new production 6072A is a low-noise, sonically balanced, dual-triode
vacuum tube recommended for use in vintage and new production ELA M 251E,
C12, TF51 and similar microphones. Screened TELEFUNKEN Elektroakustik,
this tube is included in new ELA M 251E microphone systems.
Shop Tubes
Fixed-bias vs Self-bias
The original 1950s C12 amplier uses a xed-bias design which requires
applying a separate negative voltage to the grid of the 6072A triode. Varying
this voltage changes the operating point of the tube, which impacts a number
of characteristics including gain, sensitivity, and frequency response. It has
long been a common modication to disconnect the bias voltage and add a
cathode resistor and capacitor, eectively converting the amplier to self-bias
conguration. Self-bias is largely seen as an improvement over xed-bias, as
it’s known to improve both the frequency response and headroom and requires
a less complicated power supply. In self-bias, the cathode voltage is eectively
set by the value of the cathode resistor and the current draw of the tube, while
the negative grid voltage is left to naturally settle based on the specic tube’s
parameters. This conguration is found in vintage and new-production ELA M
251E’s and is standard in the Telefunken C12.
8TELEFUNKEN Elektroakustik 9Diamond Series
The 251 and C12 both feature the CK12, but the capsules are polarized
very dierently in the two models. In the C12, the front membrane is always
grounded, and the back membrane varies from 0 to 120 volts, whereas in the
251, both the front and back membranes vary between -60 and +60 volts.
Though the overall range is identical, the dierence in approach does account
for a discrepancy in how the capsule transfers sound energy into an electrical
signal. The polarizing network itself was also moved inside the microphone
in the 251, with the switch now found on the front of the microphone. It is
speculated that this was done to imitate the look of the U47. The number of
polar patterns was also reduced to three: Cardioid, Omnidirectional and Figure
8. There are also obvious dierences in the mechanical assembly, body tube
diameter and headgrille size and construction between the two microphones.
The sonic dierences between the 251 and the C12 can largely be attributed to
the headgrille design, change in polarizing network, and change in tube bias,
since they share the same capsule, tube, and output transformer.
It is generally estimated that approximately 2500 C12’s were made during
AKG’s 10-year production run from 1953 until 1963. In 1962, AKG released the
C12A, which also featured a CK12 capsule but with a dierent tube, circuit, and
transformer. The later version of the famed CK12 capsule is also found in early
versions of the C 414 which was initially released in 1971. The modern “VR”
version was released in 1994 as a replica of the original C12, but aside from
the 6072A tube, it has little in common with the capsule, sound, or circuit of the
original C12. A stereo version, the C24, was introduced in 1959 and stayed in
production years after the C12 was discontinued.
The TELEFUNKEN Elektroakustik replica C12 features a historically accurate
CK12 capsule, made by hand in South Windsor, CT, a 6072A vacuum tube in
self bias conguration, and a T14/1 output transformer made by the original
European manufacturer, Haufe. The polar pattern box has been combined
with the power supply into one unit. This does not aect the sound in any way,
but greatly improves the functionality by limiting the number of interconnects,
cabling, and equipment needed for operation. Mechanically, most parts found
in the replica are compatible with vintage units though t cannot be guaranteed
due to subtle changes in the original design. While the original units feature a
plated body with an engraved AKG logo, the Telefunken replica features a gray
powder coated body and classic Telefunken Diamond badge.
C12 History
The C12 was introduced by AKG, or Akustische und Kino-Gerate (Acoustic and
Film Equipment), in 1953. It was designed by AKG engineer Konrad Wolf to
compete with the already-popular U47. While both microphones feature a large
diaphragm capsule, vacuum tube, and output transformer, little else is similar.
Unlike the U47, the C12 features nine remotely switchable polar patterns from
an external switching box connected to the microphone’s power supply. Initially
intended for capturing classical performances and broadcast applications, it
quickly found its way into the recording eld. AKG’s edge terminated CK12
capsule produced a more open and detailed sound compared to the U47’s mid-
forward and present center-terminated M7 capsule.
The CK12 capsule is probably the most famous microphone capsule ever
produced and was a major breakthrough in design at the time. Though many
changes were made during the original production years, all true CK12’s feature
dual-backplates with edge-terminated diaphragms. Those changes include
diaphragm materials and weights, as well as changes to the size of the chamber
between the backplates. There were also changes to the output transformer
used over the production run. Early versions have the V2148 transformer, while
the later have the more famous Haufe T14/1 transformer, which in itself varied
over the years. There have also been some minor cosmetic and mechanical
changes to the microphone, including the shape and height of the headgrille,
and variations in hardware, cable assembly, and power supply design.
When Telefunken stopped distributing the U47 in 1958, AKG was contracted to
develop a new agship condenser microphone. AKG’s design was the ELA M
251, essentially a modication of the C12. The C12, basically unchanged, was
also re-branded as the Siemens SM203 and SM 204. Though the 251 is based
on the C12, there were many modications made to the original design that
account for the functional and sonic dierences between the two models. A
major change found in the 251 is the self-biasing of the vacuum tube, compared
to the xed bias conguration found in the C12. With self bias there is no
calibration necessary when changing tubes and it is generally thought of as
sounding more open and natural. It is a very common modication to convert
AKG C12’s to self-bias. The TELEFUNKEN Elektroakustik C12 is self biased.
Another dierence is that the tube socket is inverted in the 251, making the high
impedance line from capsule to tube grid signicantly shorter.
10 TELEFUNKEN Elektroakustik 11Diamond Series
C12 Technical Specications
Specication C12
Type Vacuum Tube Condenser
Polar Pattern 9-Pattern Variable including Cardioid,
Omnidirectional, Figure-8
Frequency Range 20 Hz - 20 kHz, ±3 dB
Power Source External Power Supply
Capsule TELEFUNKEN CK12 – Edge Terminated
Large Diaphragm
Tube TELEFUNKEN 6072A
Transformer Haufe T14/1
Sensitivity 10 mV/Pa ± 1 dB
THD at 1 kHz, 1 Pa (Amplier) < 0.25%
Output Impedance 200 Ω
Maximum SPL (for 1% THD) 130 dB
S/N Ratio 85 dBA
Self-Noise (Amplier) 9 dBA
Dimensions 250 mm L x 42.5 mm Dia
Weight 567 g
Revered for its smooth and airy frequency response, if there were ever a
microphone that was the epitome of classic, hi-delity sound, it would be the
C12. While it is a fantastic choice for all types of instruments, the C12 lends
itself especially well to drum overheads, acoustic guitar, and vocals. Its silky
top end provides plenty of air without sounding harsh or articial. Its midrange
speaks clearly and articulately, capturing the source with a natural presence.
Its low end is tight and focused, perfectly balanced with the rest of the
frequency range. The TELEFUNKEN C12 builds upon the original design with
the implementation of cathode self-biasing operation, a conguration which is
quieter and more consistent than the original xed-bias conguration.
CK12 Capsule
6072A Vacuum Tube
Haufe T14/1 Transformer
Our historically accurate replica CK12
capsule is made in limited quantity in
the USA. This edge-terminated, dual
diaphragm design is considered one
of the truly best sounding capsules
ever created.
This new production, TELEFUNKEN
Elektroakustik-screened 6072A dual
triode vacuum tube is electronically
and sonically tested and burned-in
in the USA. They are hand-selected
for use in the C12 and provide stellar,
vintage-correct performance.
This output transformer is made to
vintage specication by the original
European manufacturer, Haufe,
exclusively for us. The T14/1 provides
a sonically pleasing tonality with
excellent low frequency clarity.
12 TELEFUNKEN Elektroakustik 13Diamond Series
Warranty
Repairs & Service
System Congurations
TELEFUNKEN Elektroakustik warrants that any capsules and tubes used
in their microphones are free from defects in material and workmanship for
the period of ninety (90) days from the original date of purchase, and agree to
replace any capsule or tube which, under normal installation and use, disclose
such defect. This is provided that the complete microphone is delivered to
TELEFUNKEN Elektroakustik intact for examination and provided that such
examination discloses, in the judgment of TELEFUNKEN Elektroakustik, that
the tube or capsule is indeed defective. Upon replacement, TELEFUNKEN
Elektroakustik will provide an additional 90-day limited warranty on the new
capsule or tube.
This warranty does not extend to any capsule or tube which appears to have
been misused, altered, neglected, damaged, or stored in any manner that
adversely aects it, or used in violation of instructions furnished by us. This
limited warranty shall be void and of no further force or eect whatsoever if
the microphone is repaired or modied by any person other than an authorized
representative of TELEFUNKEN Elektroakustik. This warranty shall not apply
to any defect, failure, or damage caused in whole or in part from attempts by
personnel other than TELEFUNKEN Elektroakustik’s to open, repair, or service
the microphone; nor to damage to a unit which has been modied by persons
other than TELEFUNKEN Elektroakustik personnel.
Please visit www.t-funk.com/warranty to register your microphone.
Repairs on new TELEFUNKEN Elektroakustik microphones are covered under a
limited warranty plan and repair costs will be determined based upon the date of
purchase and the date in which the warranty was registered. Repairs & Service
covered under the warranty plan are done at no charge for labor, parts and
service.
Please visit www.t-funk.com/repairs for microphone repair information.
Like all TELEFUNKEN Elektroakustik tube microphone Stereo Sets, the C12
Stereo Set includes two meticulously matched microphones and a dual
power supply in a premium ight case. The American-made power supply is
capable of powering both microphones at the same time and controls the polar
patterns of both microphones. This system is capable of all common stereo
recording techniques including XY, ORTF, Spaced Pair, Blumlein, and Mid-Side.
The included carrying case easily holds both sets of microphones, cables,
and accessories. All critical components, including the capsules, tubes and
transformers, are hand-selected and tested for matched gain and frequency
response. These sets oer the user the knowledge and comfort that the tools
they are using will give identical responses for the most critical stereo recording.
Stereo Sets
System C12 C12 Stereo Set
M 910 Power Supply X
M 910S Power Supply X
M 810 Cable X 2X
WB10 Wooden Box X 2X
M 751 Shock Mount X 2X
FC10 Flight Case X
FC10S Flight Case X
Warranty Registration
Microphone Repair Form
14 TELEFUNKEN Elektroakustik
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