Tube Condenser Microphone

AKG C12A Tube Condenser Microphone

The development of the AKG C12A condenser microphone has been based on the experience and requirements of leading recording studios:

  • Twin diaphragm
  • Exceptionally low distortion due to nuvistor low frequency circuit in the preamplifier
  • Nine variable patterns may be remotely selected
  • + 2.5 db deviation from frequency response curve

This microphone has been evaluated under studio conditions for years. It embodies the highest professional standards and has been acknowledged as a significant advancement in studio microphone technique.


Power supply and pattern selectors for directional characteristics of the AKG C12A Tube Condenser Microphone are housed one unit the AKG N12A.

AKG C12A Tube Condenser Microphone Applications

Recording and sound reinforcement applications where highest studio quality is demanded:

  • Recording studios
  • Broadcast
  • Television
  • Motion picture
  • Concert hall
  • Theatre
  • Opera

Especially suitable for stereo recordings because each AKG C12A microphone is identical in frequency response, directional characteristics and phasing.

AKG C12A Stand Adaptor

To fit the AKG  C12A tube condenser microphone to the stand adapter (D turn nut Q) to insure electrical contact and to secure the microphone on the stand adapter. By turning the nut into opposite direction the microphone contacts are pressed out of the stand adapter take the microphone off without force.

The 66 foot microphone cable ® is fixed to the stand adapter. A 6-pin Cannon connector RWK-6-22 0-1/4“, on the opposite end of the cable, fits into the power Supply receptacle.

The stand adapter incorporates the rubber shock mount .. It insulates the microphone from the stand and prevents pick up of disturbing noise and electrical hum, even on contact with grounded metal. The microphone may be tilted 180° by loosening the wing nut. The universal stand adapter can be applied to threads of 3/8“, 1/2“ —26 and 5/8”-—27.


TheAKG N 12A is t integral part of the studio condenser microphone system of the AKG C 12A. Its features are:

  • On-off switch.
  • Pilot light.
  • Pattern selector. Nine variable patterns may be selected during recording. Each is identical in phasing and sensitivity.

Advantages: Adaptseasily to a wide variety of room acoustics and allows for many special sound effects.

  • Bass attenuator with positions 0, -7 db and —12 db. Provides for roll-off of low frequency to prevent unwanted room noise and for close up speech recording.
  • The handle for easy portability.

The N 12A weights only 4 pounds, is handy and is suitable for portable use as well as studio rack mounting.

Rear panel of AKG N12A power supply:

  • Cannon connector RWK-6-318L to accomodate microphone cable MK 12A
  • Cannon XLR-3-14 to accomodate audio cable NF 12A
  • 4-conductor power cable with separate housing (shield) and supply ground (minus plate).

AKG C12A Tube Condenser Microphone Operations

The microphone cable MK 12A connects microphone (C 12A) with power supply unit (N 12A).

The audio cable NF 12A cennects power supply unit with the audio equipment.

The power cable connects the power supply unit with power line of 110 v/60 cycles i 10% (adjustable to 220 v), and to the ground systems. A thermo—resistor protects the power supply unit from overheating by turning the unit off automatically.

The N 12A power supply unit supplies the required power for the nuvistor 7586 in the microphone. The filament voltage of the power supply unit is stabilized by a Zener diode and a transistor. thereby allowing a cable length of up to 1000 feet, without re-adiustment of voltages.

High zero stability of the nuvistor circuit, in spite of grid leakage resistance and additional reduction of noise, is achieved by intentionally reduced filament voltage (5.0V). ‘

The low distortion. at 500 ohm output resistance 0.4% at 100 ubar (114dbspl) or 1% at 300 ubar

(124 db spi), is achieved by a special anode circuit.

Check out our article on the history of the AKG C12/C414 Sound Bites – A Very Rough Guide To The AKG C12 and C414


View the AKG C12A tube condenser microphone Classic Brochure.


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