Overview

Vacuum Tube Stereo Ribbon Microphone

The SF-24V vacuum tube stereo ribbon microphone is the pinnacle of our SF-series stereo microphones. The sound pickup is lush, smooth and natural, with outstanding stereo imaging and superb transient response. The tube electronics provide increased midrange reach, unmatched clarity and detail, and an airiness previously unheard of in ribbon mics. Utilizing the same proprietary tube electronics as in our TEC Award winning R-122V ribbon microphones, the SF-24V delivers the ultimate in stereo ribbon miking for the true connoisseur of recorded sound.

The SF-24V's independent tube circuits provide an output level of -38 dB, suitable for use with any professional preamplifier. With self-noise of lower than 18 dB, the SF-24V's ultra-quiet operation is suitable for the most demanding classical and acoustic recording applications.

Like an SF-12, the SF-24V 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.

Product Details

  • Vacuum tube circuitry provides high output and impedance matching
  • True stereophonic (Blumlein and M-S) recording from one coincident microphone
  • High SPL capabilities
  • No distortion up to maximum SPL rating
  • Extremely low residual noise
  • Ribbon elements are not affected by heat or humidity
  • Absence of high frequency phase distortion
  • Equal sensitivity from front or back of elements
  • Consistent frequency response regardless of distance
  • High efficiency, matching toroidal transformers
  • Very low magnetic leakage
Acoustic Operating Principle
Electrodynamic pressure gradient with vacuum tube electronics.
Vacuum Tube
JAN mil-spec 5840W pentode wired in triode configuration
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
Microphone Output Connector
Male XLR 7 pin (stereo*)
Power Supply Output Connectors
Two Male XLR-3 pin
Power Requirements
Plate supply: 135 VDC @2ma, Filament supply: 6 VDC@ 150ma from dedicated power supply.
Supply Current
4 mA per channel
Microphone Dimensions
270mm X 39mm (base) X 25mm (top) (10 5/8"X 1.5" X 1")
Weight
583 grams (20.5 oz)
Finish
Dull Satin Nickel, Optical Black finish optional