The "bypass" function switch (6) bypasses the unit for reference.
A relay simply disables the unit's output, and shortens the input
to the output XLR's. The power indicator light will dim a bit to
show that the unit is now bypassed. If you wish to use the unit
for straight line gain, but with bypassed equalisation, all eq is
fully turned off (hard bypassed) when the mode select switches (2)
are in their centre position.
The G14 consists of five bands with selectable frequencies, 'Q',
and boost/cut. Frequency is selected by the upper row of switches
(1), and boost, bypass, or cut is selected for each individual
band by the mode switch (2). The sharpness, 'Q', of each filter is
selected by the Q-knob (4) 'sharp' or 'high Q' is at the clock-
wise direction - towards the mark 'H'. The 'Level' control (3)
controls the amount of applied boost or cut - depending on what
function is selected by the mode switch.
The Output trim pot (5) controls the signal level from the filters
to the output driver stage and the output. The trim range is ca.
+/-3dB, and unity gain is somewhere around 12 O’clock at the
output trim pot. The output impedance of this unit is 650 Ohm, and
is - like the input - floating transformer balanced.
Note that the way we implement the passive filtering has a number
of side effects that should be considered in use:
First of all, the range of maximum boost is limited to some
10-12dB at each band - depending on 'Q' setting - the maximum
obtainable cut is larger at extreme settings of the 'level'
controls.
Second, there is no 'adding up' of adjacent bands - if you boost
two bands at the same (or close) frequency, you won’t end up with
double the boost/cut range. This is true for all passive equalizer
topologies.
Third, because of the parallel-passive architecture, the maximum
available 'Q' is somewhat higher at the upper frequencies of each
band than at the lower frequencies of that given band, and is
sharper in cut mode than in boost mode. This distribution of fil-
ter bandwidth gives a very intuitive control of the equalizer, but
also somewhat limits the maximum available boost sharpness of the
individual filters.
Fourth, the amount of boost obtainable is dependent on the output
(source) impedance of the previous unit - the passive filters will
load the input at high levels of boost, which limits maximum
available boost when driven from high source impedances. This
should, however, not affect sound quality - only the amount of
control.
