User guide

Introduction
Congratulations on your purchase of a Royer Labs model SF-24 stereo active ribbon
microphone. The SF-24 is a handcrafted precision instrument capable of delivering superior
sound quality and exceptional performance. The SF-24 represents a new level of performance for
ribbon microphones, combining sophisticated technological advancements with old-world
craftsmanship. The SF-24 incorporates two independent head amplification systems that operate
on standard 48-volt phantom power, similar to standard condenser microphones. This enables the
SF-24 to deliver the same sensitivity that the recording industry has grown accustomed to with
modern condenser microphones. In addition, the active circuitry completely isolates the ribbon
element from impedance mismatches, short circuits and other anomalies that can degrade
microphone performance or damage the sensitive ribbon element. The SF-24 breaks the long-
standing taboo associated with ribbon microphones and phantom power; it actually requires
phantom power to operate.
This instruction manual describes the SF-24, its function and method of use. It also describes the
care and maintenance required to ensure proper operation and long service life. The User Guide
section of this manual offers practical information designed to maximize the performance
capabilities of this microphone.
Royer Labs products are manufactured to the highest industrial standards using only the finest
materials obtainable. Your model SF-24 went though extensive quality control checks before
leaving the factory. Normal care is all that is required to assure a lifetime of trouble-free service.
Please read this manual thoroughly in order to become familiar with all of the SF-24’s
capabilities. It will assist you in making the most of your microphones’ superior acoustic
properties. This manual is a handy reference guide and we suggest you refer to it whenever
questions arise on the use and care of your SF-24 ribbon microphone.
Active Ribbon Technology
The heart of the SF-24 is its proprietary electronic system consisting of specially designed
toroidal transformers and electronic buffering stages. This system provides excellent frequency
response, extremely low noise and distortion, and high SPL handling (130 dB) without the use of
pads. It gives the SF-24 an output level comparable to that of condenser microphones, and its
buffer stages provide a low impedance output and present a perfect impedance load to each of
the ribbon elements. Unpowered ribbon microphones suffer substantially degraded frequency
response and lowered gain when they are paired to a preamp with too low an input impedance.
With the SF-24‘s active electronic system, the microphone’s frequency response and output are
much less affected by variations in the input impedance of the following preamp.
Sonically the SF-24 differs from the unpowered SF-12 in one subtle way; due to the extra iron in
the SF-24’s much larger transformers, low-end frequencies sound slightly tighter and more
focused.
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