Royer Labs
Professional Audio Products
dBooster2
Stereo in-line Microphone and DI (Direct Injection) Signal Booster
With the introduction of the original dBooster, low-output passive microphones could be boosted with up
to 20dB of clean signal boost and superior sound quality. The dBooster2 takes that concept to the next
level.
The Royer model R-DB22 is a phantom powered two-channel in-line level booster/buffer for passive low-
output ribbon and dynamic microphones and incorporates a high-impedance Direct Injection input for
guitars and other Hi-Z sources.
An integrated combination input jack accommodates standard 3-Pin microphone XLR inputs and ¼-inch
high-impedance inputs. The dBooster2 is designed for professional applications and provides two levels
of clean boost in both the low-impedance microphone mode; 12dB or 20dB and the high-impedance mode;
0dB (unity) or 8dB, selectable by a front panel switch.
How to set up your dBooster2
NOTE: It is a good idea to make all of your connections before activating phantom power and turning up
your preamp level control!
One of the unique features of the dBooster2 is that each channel of this stereo unit is completely isolated
from the other. They are completely independent. This minimizes the chance of ground loops developing
when used with stereophonic microphones or different independent channels of microphone preamplifiers
and interfaces.
The dBooster2 goes between any non-powered ribbon or dynamic mic, ¼ Hi-Z source and your preamp,
DAW or audio interface. In the mic mode it will provide either 12dB or 20dB of signal boost for low-output
microphones. In the Hi-Z DI (direct injection) mode it will deliver unity gain (0-dB) or +8dB of gain. A
front panel switch establishes the gain setting.
When used for microphones, the microphone is connected to the INPUT of the dBooster2 via a standard
3-conductor XLR microphone cable. In the DI mode the source is connected via a standard two-conductor
¼-inch guitar type cable. The
OUTPUT of the dBooster2 is
connected to any preamplifier, DAW
or interface that is enabled with
phantom power capability.
The dBooster2 is a mic-level device
and not intended to drive line-level
inputs directly. After your
connections are made, apply
phantom-power, and slowly bring up
the preamp level to verify that the
microphone or DI input is passing
signal. To achieve the best
performance from your dBooster2
with minimal noise and distortion at
