The M270 is part of the Gefell SMS2000 modular design microphones. It consists of a M27 capsule (Omnidirectional), an amplifier body and a wooden case.
The Gefell M270 omnidirectional is part of a series of three modular condenser mics that include the M200 cardioid and the M210 hypercardioid. Each mic comes complete with capsule head and microphone amplifier and capsules are interchangeable for maximum flexibility. The combined use of ceramics and a hand stretched gold evaporated Mylar (PE) capsule provides a rich, natural tone with universal appeal for studio, broadcast, on-stage and location sound.
Since the early days of recording, engineers have migrated towards microphones that are flexible while keeping an eye on affordability. The modular design was adopted as a means to share the cost of the capsule amplifier and impedance matching system with a selection of capsules that could be tailored for a specific task.
The Gefell M270 cardioid and its family members stem from this modular approach whereby the engineer may start by investing in the base model, then order a hypercardioid or omnidirectional capsule as needs arise. This is most advantageous when ordering stereo matched sets as a variety of capsules and the shared amplifiers can be evenly paired saving significant money over buying complete assemblies.
The recent advent of 24bit/96kHz digital recording technology has obliged microphone manufacturers to revisit their designs in order to reduce the noise floor and expand the dynamic capabilities. The M270 meets this challenge with a new preamplifier that boasts both a lower self-noise and excellent transient response. This, combined with Gefell's market leading ceramic technology provides the engineer with a very powerful and flexible solution.
At first glance, the M270 looks like a typical pencil microphone. But upon closer inspection, one immediately notices the incomparable fit and finish that comes with hand-made precision of German engineering. The sleek nickel-satin finish, combined with the sculpted control zone is clearly at another level.
As a modular system, each of the three microphone capsules may be separated from preamplifier. Inside the capsule housing is the M3 capsule, a hand-stretched 12.5mm (1/2") 24-karat gold evaporated membrane with hand-machined back-plate. The M270's smaller capsule has the distinct advantage of less diaphragm distortion for a more natural and uncolored response.
The use of a rugged 'space-age ceramic housing assures stability and improves linear response as effects from temperature fluctuations are minimized. Ceramics have long been known for their ability to withstand heat or cold without the expansion and contraction associated with metals. This of course is a concern when attempting to maintain a precise gap between the membrane and the charged back plate.
To control ballistics and ensure a smooth axial response, the capsule top and side grills are actually made up of five separate meshes. The capsule housing is then mounted on a pedestal that simultaneously deflects unwanted body reflections away from the capsule while assuring a precise polar pattern is maintained. The careful control of phase cancellation benefits the M270 with both a more detailed and articulate rendering, while reducing unwanted noise from entering the capsule.
The microphone capsule amplifier employs a newly developed hybrid circuit topology. This features a transformerless, symmetrical output stage that yields both a very low self-noise and better than 148dB pressure handing.
On-board controls include a low-frequency roll-off that gently reduces rumble or run-away acoustic resonance in live settings. A 10dB pre-attenuation pad is used when extreme sound pressure levels are encountered.
Using the M270
The Gefell M270 comes factory shipped as a complete unit. The capsule head may be disconnected from the preamplifier body by carefully unscrewing the capsule in a counter-clockwise direction. Normally, these are kept together as a unit. Using the M270 is simply a matter of connecting the microphone to a standard 3-pin XLR cable and supplying power from typical 48V phantom from the console.
As the Gefell M270 is both broadband and capable of extreme dynamics, placement options are virtually unlimited. For situations where vibration-borne noise may be encountered, the optional EA21 elastic suspension is recommended. The EA21 features a sturdy microphone clamp that secures the mic, no matter what angle is used.
The M270 Omnidirectional (Capsule only is called the M27)
The M27 is an omnidirectional pressure gradient transducer that has been corrected with a natural sounding 10kHz presence rise making it ideal for far-field recording. By correcting the upper region with an increase in the M270's harmonic sensitivity, a sense of more spaciousness and articulation is realized.
The M270 is ideally suited for orchestra and ensemble recording where rendering of the source and the reverberant field is desired.
The Gefell M200 series of modular microphones provides the engineer with a flexible system that is well suited for all types of recording environments including recording studio, foley, sound stage and broadcast.
The combination of a gold-evaporated diaphragm and a unique ceramic housing, coupled with a newly developed low noise capsule amplifier, yields a microphone system that is natural sounding, extremely linear, and predictable in even the harshest environments.
Each M200, M210 and M270 is shipped complete in a handcrafted, wood storage box. Additional capsules may be factory ordered individually or in stereo-matched sets.
The M200 cardioid, M210 hypercardiod and M270 omnidirectional mics, comprise a modular system of mics with interchangeable capsules. Each microphone has an extended response for extremely accurate reproduction throughout the audio range. Ideal for recording, broadcast and live reinforcement where natural and colourless results are needed. With deluxe wood case.
Modern small membrane capsule
Polar patterns available: Cardioid, Hyper Cardioid, Omni
Polar pattern: Omni Frequency range: 40 ... 20000 Hz Sensitivity at 1 kHz: 10 mV/Pa Switch position "reduced bass roll-off" at 60 Hz: -15 dB Rated impedance: 150
Equivalent loudness level due to inherent noise:
CCIR 468-4: 26 dB
DIN EN 60651: 18 dB - A
Signal-to-noise-ratio (re. 1 Pa at 1 kHz):
CCIR-weighted : 68 dB
A-weighted: 76 dB
Max. SPL for THD
0,5 %: 138 dB
with 10 dB preattenuation: 148 dB
Total dynamic range of the microphone amplifier: 120 dB "Current consumption (P 48, DIN 45596, IEC 268-15)": 3 mA Output connector : 3-pin XLR-connector, goldplated contacts Weight: 130 g Dimensions (L x Ø ): 166 x 21mm