A stereo pair of matched M930 large cardioid condenser microphones with TD93 ORTF set.
Large diaphragm, transformerless studio microphone
The M930 is a compact, large diaphragm microphone that combines the latest Gefell M9 gold evaprated capsule with an optically isolated capsule amplifier for low self-noise, excellent dynamic handling and the added benefit of greater placement ease. Available in choice of cardioid (M930) or hypercardioid (M940) models, these Gefell gems are also available in stereo matched kits complete with choice of XY or ORTF mounting hardware.
On first view, one is immediately amazed at how compact the M930 is. But even more amazing is the incorporation of the M9, a full-size 1-inch (25mm), 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 M930'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 M930 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 M930 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 M930 produces a clean, distortion-free sound over an extremely wide dynamic range.