Product Details
SF-24

Phantom Powered Stereo - Dual Small Ribbon Elements

SF-24 is the phatom powered version of award winning SF-12 stereo ribbon microphone, with the addition of condenser-level output and impedance matching circuitry. Designed to work with phantom power, the SF-24 makes preamplifier mismatches and gain-related noise a thing of the past. The SF-24’s output of -38 dB is a full 14 dB more sensitive than our non-powered SF-12, putting its sensitivity on par with that of phantom powered condenser microphones.

Product Details
Like an SF-12, the SF-24 is actually two matched ribbon microphones placed one above the other in a coincident pair, each aimed 45 degrees from center in the classic Blumlein configuration. The magnet/pole piece structure of each ribbon transducer delivers a wide, uniform frequency response with no substantial peaks or dips, and the 1.8-micron ribbons produce superb transient response. Frequency response is excellent regardless of the angle of sound striking the ribbons and off-axis coloration is negligible. The SF-24’s extension cable comes with a Y adapter that splits into separate 3-pin male XLR connectors labeled “Upper” and “Lower” for the upper and lower capsules of the microphone (when held vertically). Gain Our active ribbon™ mics (SF-24 and R-122) are as sensitive as phantom powered condenser microphones, allowing you to use virtually any mic preamplifier or board pre. Conventional ribbon microphones are 15 to 30 dB less sensitive than condenser mics, necessitating the use of high-quality, high-gain microphone preamplifiers when recording softer sound sources like acoustic instruments, vocals and room ambiance. The SF-24 contains two fully balanced, discrete head amplifier systems utilizing specially wound toroidal transformers and ultra-low noise FET’s, each delivering a sensitivity of -38 dB. This lets you mate an SF-24 to any preamplifier with average gain characteristics. Even with quiet sound sources, you’ll have enough level to drive any recording medium. It is important to note that the SF-24’s higher sensitivity does not create additional self-noise. All of the SF-24’s increased level comes from its large, specially wound toroidal transformers – that wonderful thing called “free gain.” The level at the each of the transformers is actually hotter than what comes out of the microphone. The phantom powered system operates at less than unity, adding no noise of its own. This system took years to develop and is in patent pending status. Impedance Matching The electronics in the SF-24 provide a perfect load to the ribbon elements at all times, allowing the microphone to deliver 100% of its full sonic potential regardless of the input characteristics of the following mic-pre. Due to its low-impedance output, SF-24’s can also be used on extremely long cable runs with minimal signal loss. A good impedance match is critical to ribbon microphones. Impedance mis-matching loads a ribbon improperly, resulting in loss of low end, diminished body, lowered sensitivity and an overall compromised performance. With our Active Series ribbon mics, the ribbon element sees a perfect impedance at all times, regardless of the preamp you use, so its performance will never be compromised by the effects of improper loading. In addition, the ribbon element cannot be damaged by phantom power, electrical glitches or miswired cables. Recording Like the SF-12, the SF-24 is uncanny for creating “you-are-there” stereo recordings that capture not only the instrument(s) being recorded, but, depending on how the microphone is positioned, varying degrees of the acoustical space. In addition, the increased sensitivity and impedance matching circuitry allows for more consistent results in a variety of recording situations and with a wider selection of mic pre’s. For mono recording, phase compatibility between the two sides of the SF-24 is excellent. This allows you to combine the two channels perfectly in mono without creating undesirable phase artifacts. This is particularly useful when capturing a wide sound field in mono; for instance, a singer who tends to move off the “sweet spot” of a mono microphone. Either side of the SF-24 can also be used individually as a mono microphone. The SF-24 excels on classical piano, drum overheads, ensemble and orchestral recordings, a wide variety of percussion instruments, virtually all acoustic instruments, small vocal ensembles, large choirs, etc. Recording in Mono Phase compatibility between the two sides of the SF-24 is excellent, allowing you to combine the two channels for mono recording without creating phase artifacts. This is particularly useful when capturing a wide sound field in mono; for instance, a singer who tends to move off the “sweet spot” of a mono microphone. Either side of the SF-24 can also be used individually as a mono microphone.
Technical Specification
Acoustic Operating Principle Electrodynamic pressure gradient with active electronics
Polar Pattern Crossed figure-8's
Generating Element 1.8-micron aluminum ribbon
Frequency Response 40-15,000 Hz +/- 2dB
Sensitivity -38 dB (re. 1v/pa +/-1dB)
Self-Noise < 18 dB
Output Impedance 200 Ohms
Rated Load Impedance 1K-Ohm
Maximum SPL >130dB
Output Connector Male XLR 5 pin (stereo*)
Power Requirements 48-Volt Phantom Only
Supply Current 4 mA per channel
Dimensions 270mm X 39mm (base) X 25mm (top) (10 5/8" X 1.5" X 1")
Weight 583 grams (20.5 oz)
Finish Optical Black, 18K Gold (optional)
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