©2021 by IronAgeAudioworks 3
Controls
The GAIN knob adjusts the gain of the preamplifier in mic mode
only. In line mode the gain knob does not change the level.
The MIC switch engages the mic pre circuit and enables the
phantom power. When the switch is down, phantom power is
defeated, and the input is a fixed unity gain stage.
The PAD switch engages a 20 dB pad in mic mode and a 6 dB
pad in line mode.
The +48 switch provides phantom power to the microphone.
Because of the 500 series format, phantom power has the
potential to be turned on inadvertently. Please be aware before
turning it on!
The HPF switch engages an active 60 Hz high pass filter.
The COMP switch engages the VCA compressor.
The FF/FB switch changes the sidechain detection for
compression between feedforward and feedback mode.
The COMP knob is a combination of several compressor
functions. As the knob is rotated clockwise, threshold is lowered,
ratio is raided, and makeup gain is increased. The net gain
through the compressor is approximately constant, but the
threshold is lowered while and peak reduction and gain of signals
below threshold increase as you rotate. The sidechain detector is
set with a threshold of approximately -10 dBu. It sounds
complicated, but in practice it is very simple
from mild, gentle compression to complete squashing.
The EQ switch engages the passive EQ.
The high band is a shelf offering +/-15 dB of correction at 10 kHz.
The mid band is an inductor peaking band offering +/-15 dB at a center frequency of 1.2 kHz.
The high band is an inductor shelf offering +/-15 dB of correction at 100 Hz.
