Operating instructions

2-6

INSTALLATION ORBAN MODEL 9400

OPTIMOD-AM. The amount of rolloff is adjustable with the filter's high

frequency ROLLOFF control to complement the setting of the HF

GAIN

control on OPTIMOD-AM.

B) Change the jumpers to the desired rolloff. See Figure 2-4 on page 2-5.

C) Connect the output of your modulation monitor to the Input terminals of the

Monitor Rolloff Filter.

 If the output impedance of the source is between 0 and 35 ohms (such as

the output of an opamp), connect the source between the 0

OHM

SOURCE and COM terminals on the rolloff filter chassis.

 If the output impedance of the source is 600 ohms, connect the source

between the 600-OHM

SOURCE and COM terminals.

 If the output impedance is some value in between, connect a resistor be-

tween the source's output and the Monitor Rolloff Filter's 600-OHM

SOURCE terminal so that the total source impedance seen by the Moni-

tor Rolloff Filter is 600Ω (external resistor + output impedance of source

= 600Ω).

 If your console monitor or monitor amplifier input is bridging (like virtu-

ally all modern amplifiers), set the TERMINATION switches on the Rolloff

Filter to ON.

 If the console monitor or monitor amplifier input impedance is a true

600Ω, set the TERMINATION switch on the Rolloff Filter to OFF.

D) Connect the input of your console monitor or monitor amplifier to the

OUTPUT terminals on the Monitor Rolloff Filter.

Figure 2-5: Frequency Response Curves as Function of R

OLLOFF Control,

Monitor Rolloff Filter Strapped for 18 dB/Octave