©2021 by IronAgeAudioworks
3
Controls
The GAIN knob adjusts the gain of the preamplifier. In the first
three positions, it is in line input mode, which bypasses the mic
input transformer and engages a pad. Line mode also
disconnects phantom power from the input. In the final seven
modes, the net gain is adjusted to the amount indicated. A pad is
automatically engaged in the first two positions.
The +48 switch provides phantom power to the microphone. This
only works in mic gain points.
The HPF switch engages an active 80 Hz high pass filter.
The EQ switch engages the passive EQ.
The high band is shelf, where each step adjusts the frequency
response at 10 kHz by 2 dB from -10 to +10.
The mid band is an inductor peaking band with eleven selectable
frequencies. The cut or boost function of the mid band is set by
the boost/cut switch. The amount of gain or cut is set by the gain
knob. Fully clockwise is +15 dB, counterclockwise is 0 dB. A
feature of the passive inductor EQ is that the cut behavior is
narrower than the boost.
The low band switch has two functions. Counterclockwise from
center a 50 Hz shelf is engaged in 3 dB increments up to -15 dB.
Clockwise from center selects the boost frequency and engages
the boost control knob. The boost control knob can be rotated to
a fully clockwise position to turn the low frequency band off. This
ensures a flat frequency response.
