Royer Labs R-122V - Manual (Page 11)

interface with other equipment with minimal noise or hum. There are many excellent
preamplifiers on the market today. Choose one that fits your budget and offers good performance,
but remember that you get what you pay for. If you have the opportunity to audition one or more
preamplifiers before you buy one, do so. Microphones and preamplifiers work together like a
team and some are better matches than others.
The R-122V vacuum tube ribbon microphone is capable of substantial output signal, especially if
used in conjunction with very loud signal sources such as guitar amplifiers. It is therefore
recommended that the microphone preamplifier have a switchable pad to prevent the possibility
of overloading the preamplifier’s input stage electronics. Some preamplifiers are more
thoughtfully designed than others, and a suitable pad will be provided before the active
electronics, not incorporated into a “feedback loop” as with some cheaper models. Even with the
pad engaged, a poorly designed preamplifier can still produce unwanted distortion due to
overloading.
With variable input impedance preamplifiers, a good rule of thumb is to set the Z-switch for the
highest input impedance.
In conclusion, preamplifier coloration is optional and a matter of personal taste. Some engineers
enjoy the effect of coloration while others strive for absolute transparency.
Equalization & Ribbon Microphones
One of the great strengths of ribbon microphones is how well they take EQ. Even with
substantial amounts of equalization, ribbons retain their natural, “real” quality. For example,
when a lead vocal is being performed on an R-122V, you can actually boost upper-end
frequencies to the point where the R-122V emulates the performance curve of a condenser mic
with excellent results. This is not to say that ribbon microphones can replace quality condenser
mics in all circumstances, but the EQ friendliness inherent in ribbon microphones does allow for
an enormous amount of flexibility.
Ribbon mics take EQ extremely well due to their inherent low self-noise (less than 15dB),
unusually smooth response characteristics, and freedom from off-axis coloration. Dialing in high
amounts of equalization on condenser or dynamic microphones brings up equal amounts of the
microphone’s distortion products and noise; garbage that contributes to an unnatural, unpleasant
sound. Because distortion and self-noise are almost nonexistent in quality ribbon microphones,
high levels of EQ can be used without adding harshness or excessive noise.
Hum, Noise & Mic Orientation
All dynamic microphones, including ribbons, are electromagnetic devices and are, to some
degree, susceptible to picking up stray EMF (electro-magnetic fields). Power transformers (such
as those found in guitar amplifiers) and alternating current motors are the most likely sources of
radiated noise. Building wiring and electrical utility transformers are other likely sources. A well-
designed microphone provides shielding to minimize the effects of stray magnetic radiation. In
severe cases complete isolation is impossible and the result is hum or buzz. Passive ribbon
microphones can potentially manifest this condition to a greater degree because of their higher
gain requirements. Even an active ribbon microphone like the R-122V is not completely immune
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