User guide

Radial Engineering Ltd.
PreComp™ Preamp and VCA Compressor
True to the Music
®
1
OVERVIEW
As the name implies, the PreComp is a combination preamp and compressor jammed into a
single wide 500 series module. By housing both processors together we can optimize each
gain stage so that it works with minimal fuss. This accelerates setup times and eliminates
many of the challenges that make getting compression to sound right.
PRE OUT COMP IN
MIC
INPUT
LINE
OUTPUT
MIC
PREAMP
VCA
COMPRESSOR
OMNIPORT
I/O
The Preamp
The design begins with a state-of-the-art microphone preamp coupled with Radial’s unique
Accustate gain control. Unlike traditional preamps that only achieve their optimal signal-to-noise
when pushed to maximum, Accustate employs a dual wafer potentiometer that simultaneously
sets the input sensitivity and preamp gain so that the signal-to-noise ratio remains constant at
all levels. This is particularly important when recording in the digital domain where even the
slightest bit of noise can be audible.
NOISE FLOOR
MINIMUM GAIN - NARROW SIGNAL-TO-NOISE RATIO
MAXIMUM GAIN - WIDE SIGNAL-TO-NOISE RATIO
Traditional preamp gain Accustate preamp gain
The preamp is equipped with +48V phantom power for condenser microphones and active
direct boxes, a 180° polarity reverse to help phase align two mics when recording an instrument
in stereo and a handy high-pass fi lter that eliminates low frequency rumble to help clean up
your tracks. Visual monitoring is provided by two LEDs that show below or above threshold and
a third that lets you know when clipping.
MIC
INPUT
LINE
OUTPUT
OUTPUT
GAIN
MIC
PREAMP
ACCUSTATE
GAIN
VCA
COMPRESSOR
+48
VOLTS
180°
REV
HI-PASS
FILTER
PREAMP COMPRESSOR
The Compressor
The preamp section feeds a full-featured VCA compressor with adjustable threshold,
compression ratio and gain make-up controls. The advanced feed-forward compression
algorithm reads the incoming program material and automatically transitions from soft-knee to
hard-knee as the signal rises above the threshold. A simple slow-fast switch makes it easy to
set the compressor’s response to suit vocals, instruments or percussion.
When using the PreComp in a Radial 500 series power rack the Omniport™ is available and
functions as a signal insert and access point. Using a standard ¼” TRS insert cable you can
access the preamp and compressor sections independently or insert another processor, such
as an equalizer in between. For more information please refer to the Omniport descriptions
later in this user guide.