Fostex 350 - EXTERNAL EFFECTS AND PROCESSING; SIGNAL PROCESSING ON INDIVIDUAL CHANNELS

If using the optional meter bridge, connect an audio oscillator
to the input of one of the channels, set the trim, level and
routing controls so that you obtain “zero” level on the VU
meter. Now adjust the input level control on the following
equipment to give the same “zero” reading on its meter. If
you are not using the optional meter bridge, adjust the input
trim control just below the setting where the input overload
LED flashes, set the 4 channel buss pan pot to center and the
input and master faders to the normal operation area (be¬
tween 7 & 8). The output level from the mixer “buss out” will
be approximately -lOdBV, when the overload LED just
starts to ignite. If an audio oscillator is not available, you can
improvise by connecting a microphone and playing a single
note on an organ or other keyboard or by vocally sustaining a
note. Setting correct levels is a prime factor in attaining the
maximum dynamic range performance from any professio¬
nal audio system. While presetting inputs to external equip¬
ment need only be done once, individual input channel levels
must be trimmed when mixing various sources via various
microphones.
SECTION 4 EXTERNAL EFFECTS AND PROCESSING
External effects may be used with Model 350 in two separate
and distinct ways.
If it is required to add an effect such as reverberation or echo
to all channels, use the auxiliary buss send and 4 channel
buss in. To process an individual channel, use the accessory
send and receive jacks. Before processing, a brief discussion
of echo and reverberation is in order.
The nearest thing in real life to what is commonly termed
echo, is the effect of the repeats which you hear when you
shout in the midst of a mountain range. In the studio this can
be achieved by feeding the output of the play head of a tape
recorder or special tape loop deck back to the record heads.
Many electronic devices using “bucket brigade” and digital
electronics are available, and these do much the same job.
This effect is normally reserved as a special effect only, and
should not be confused with reverberation. The sound of
reverb is similar to that of a large empty concert hall. Reflec¬
tions of the original sound are so close and diffuse, that no
distinct repeats are heard. This effect is often simulated by
devices employing a large metal plate or torsionally driven
coiled springs. The effect is normally used to fill out the sound
of a vocal or instrument which has been closed-miked, or is
otherwise void of natural reverberation. Added judiciously it
will provide commercial fullness and body to a recording. Us¬
ed excessively it can create exaggerated illusions of space
and loss of clarity and intelligibility.
The echo or reverb effect is proportionately added to the direct
signal passing through the mixer.
The following describes how to connect either an echo or
reverb, or in fact any other effect such as a phaser, flanger,
doubler, etc., to the Model 350 signal path.
The auxiliary buss is used to send part of the input signal to
the effect unit.
Once processed, the effect signal rejoins the direct signal in
the appropriate four channel buss mixing amplifier.
In simplified form, the signal path looks like this:
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