Advanced Audio CM12 (C12)

The Advanced Audio CM12 is a large-format condenser tube microphone with a capsule design and tube circuitry based on those of the famous AKG C12. Like the original C12 it is an outstanding choice for vocals and acoustic instruments, including percussion, drums and grand piano, as well as for distant miking.

The CM12 features Advanced Audio’s AK12 capsule, an edge-fed, dual diaphragm capsule skinned with German mylar that has a frequency response matching within ±1.5 dB the response of the AKG CK12 capsule.

The CM12’s circuit has been optimized for the 6072a dual triode tube. The unused half of the 6072a is incorporated as a cathode follower, resulting in a much lower output impedance than that of the original circuit. This lower output impedance improves the damping factor and allows the use of a transformer with half the turns-ratio of the original C12. The result is a circuit with at least 6db more headroom than the original circuit with a better low frequency and high frequency response.

I am the original owner/purchaser and has been housed/used in a non-smoking studio. The microphone comes with the original 7-pin XLR cable, IEC power cable, power supply, shock mount, storage bag, microfibre cleaning cloth and storage case.

SPECIFICATIONS:

• Pattern Selector: 9 patterns from the power supply.
• Circuit type: 2 stage class "A" tube, CCDA  transformer coupled
• Capsule: 34mm centre fed with dual back-plate and dual 6 micron skinned diaphragms
• Capsule Polarization: 60V on the back-plate
• Tube type: selected EH6072a 
• Transformer: BV18 dual bobbin with bi-metal laminations and  8:1 ratio
• Transformer Distortion: <1%@20Hz/+13dBu and <0.05%@50Hz/+13dBu
  Max SPL: 128dB 
• Frequency response: 25Hz-20kHz + or - 3db
• Equivalent Noise Level: <15dB (A- weighted)
• S/N Ratio: >85dB (Ref. 1Pa A-weighted)
• Sensitivity: -32dBu
• Output impedance <200 ohm (load impedance <1.2K)
• Output connector: Male XLR, 7-pin gold plated