Crown VFX2 Instruction Manual page 17

3.1 GENERAL
3.2 CIRCUIT DESCRIPTION
3.2.1 Filtering Circuits
SECTION 3
CIRCUIT DESCRIPTION
R4, a 500-ohm trim potentiometer in the positive
IC1A input line, is factory adjusted for maximum
common
mode rejection and in normal applications
should not be readjusted.
a. RANGE Switches, OFF — CROSSOVER/FILTER,
Either Position
With the RANGE switches in OFF, the unity gain
output of IC1B bypasses all filtering circuits and
appears as a flat output at the Hl and LO PASS
OUTPUT jacks. Operational amplifier IC3B creates
an inverted output at the HI PASS INVERTED
OUTPUT jack and IC5B creates an inverted output at
the LO PASS INVERTED OUTPUT jack.
b. RANGE Switches (X10, X100, X1K), Mode Sw in
CROSSOVER
The RANGE switch determines the appropriate
group of 5% matched capacitors to be used in the
filter. See Table 3-1.
TABLE 3-1
RANGE SWITCH CAPACITOR GROUPS
RANGE SW
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