Model 740 Spectral Processor User`s Manual

Using the Source NR Section

With low-level tracks - solo acoustic instruments, woodwind, quiet vocals - there may be little or no “useful” detail at the extremes of the spectrum. In such cases, when the High or Low bands are turned up, low-level background hiss or rumble may become audible.

This unwanted low level information can be reduced in two distinct ways.

Low-frequency and high-frequency filters can be switched in to bandlimit the signal entering the low-level processing stage so that the unwanted signals are not boosted. Note that these filters do not affect the original audio signal, which is passed to the output without filtering

When the unwanted noise is similar in frequency to wanted low-level details the Source NR control is a better solution. The source NR circuit is a program-dependent sliding filter that moves down the signal spectrum, reducing noise when there is no signal but sliding out of the way when low-level information is present.

The Source NR can be used irrespective of the settings of the

Equalizer section. To use this section as a stand-alone noise reducer switch the EQ mode switch to In and set the Low, Mid and High controls to minimum.

SECTION 3

INSTALLATION

Installation

Unpack the unit from its box and check for any damage. Be sure to check the packing material for the power line cord and spare fuses.

Before mounting the unit in a rack or flight-case check the setting of the voltage selector and that the appropriate fuse is fitted to the unit as follows

Step 1

Using a small flat-bladed screwdriver, lever open the voltage selector/fuse holder compartment door in the power supply input connector. Rotate the voltage selector drum until it reads the correct voltage for the installation. ( The drum may also be removed from the housing and replaced with the correct voltage displayed; it will only fit one way round.)

OPEN THE

DOOR

Step 2

SPARE FUSE

(UPPER)

OCTAGONAL PEG

ROUND PEG

VOLTAGE SELECTOR

WHEEL

FUSE

ACTIVE

FUSE CARRIER

(LOWER)

FUSE

Check that the correct value fuse is fitted.

A2F4037

24