Microtech Gefell M940 Hypercardioid Condenser Microphone

NOTE: Available in satin nickel and dark bronze finishes.

Microtech Gefell's M940 is a compact, large diaphragm hypercardioid microphone that combines the latest Gefell M9 gold evaporated capsule with an optically isolated capsule amplifier for low self-noise, excellent dynamic handling and the added benefit of greater placement ease.

On first view, one is immediately amazed at how compact the M940 is. But even more amazing is the incorporation of the M9, a full-size 1-inch (25 mm), 24-karat gold evaporated diaphragm. The M9 features a hand stretched Mylar/PE substrate with a hand-drilled solid brass back-plate. All Gefell capsules are individually sorted and matched for optimum voicing.

The M9 is mounted on a triangulated pedestal that deflects unwanted body reflections away from the diaphragm, reducing phase cancellation and the effects of comb-filtering which can mask harmonic details and limit the depth of field. To reduce noise from vibration, the microphone capsule and electronics are elastically suspended inside the compact metal housing. This reduces the sensitivity to mechanical impact and structure born noise. This of course is further advantaged by the M940’s diminutive size, which has the net result of less ‘vortex’ or acoustic disturbance around the mic.

But creating a smaller body is not without challenges: As everyone knows, smaller usually means bringing the circuit closer to the sensitive element. If left unchecked this would result in an unacceptable noise floor. The M940 overcomes this technical challenge by introducing optical isolation between the 48-Volt phantom power supply and the internal capsule amplifier circuit. Optical isolation removes ‘hash’ caused by contamination and ripple from the power supply, providing a pure DC supply to the element. The M940 benefits with improved voltage stability and significantly lower self-noise.

Below the capsule, an innovative circular PC board using the very latest semiconductor technology houses the electronic impedance converter. A newly perfected transformerless circuit topology reduces the noise floor to an extremely low level and minimizes RFI susceptibility, while also raising the maximum output capability. Furthermore, the use of large, oversized capacitors provided added storage for exceptional transient handling. As a result, the Gefell M940 produces a clean, distortion-free sound over an extremely wide dynamic range.

Specifications:

• Polar pattern: Super-cardioid
• Acoustic operating principle: Pressure gradient transducer
• Frequency range: 40 Hz - 18 kHz
• Sensitivity at 1 kHz: 23 mV/Pa
• Output impedance: 100 ohms
• Noise level:
  • - CCIR 468 - 4: 12 dB
  • - DIN EN 60651: 6 dB - A
• Signal-to-noise ratio (re 1 Pa at 1 kHz):
  • - CCIR - weighted: 82 dB
  • - A - weighted: 88 dB
• Max. SPL for THD < 0.5%: 141 dB
• Max. output level:
  • - RL = 1 kOhm: 17 dBu
  • - RL = 10 kOhm: 18 dBu
• Dynamic range of electronics: 135 dB
• Current consumption (P 48, DIN 45596, IEC 268-15): 3.6 mA
• Output connector: 3-pin XLR connector goldplated contacts
• Weight without MH 93.1: 210 g
• Dimensions (L x Ø): 118 mm x 45 mm