Peavey 900 - Page 5

mixing control margins (travel). Remember, that while
mixing, it is important to allow yourself adequate
margins within which to operate and by using any of the
faders in their extreme (close to the stop) positions, you
have effectively reduced your range of control. This
manner of operation also tends to create "headroom”
problems.
These master controls allow the operator complete
flexibility for functions and should allow almost any mix¬
ing situation to be handled by the 900. As with any
reasonably complex system, experience and operator
knowledge of the equipment are essential for satisfac¬
tory performance. The mixer, like the musician's instru¬
ment. should be practiced on and learned. To properly
operate a mixer during a performance requires
thorough knowledge and trained reflexes to allow
proper responses under the stress of demanding and
sometimes sudden situations. The musician should
know his mixer almost as well as he knows his instru¬
ment, so that his reactions will be both smooth and
proper to correct whatever problem or requirement that
should arise during a performance...a professional
must work at it!
The MASTER OUTPUT FADER (7) is the control
that determines the mam output level lor the output con¬
nectors located on the rear panel. The main summing
amp, as well as the other two summing busses, are of
the very latest "zero null” type using negative feedback
tc achieve maximum dynamic range, iowest noise, and
crosstalk. The master fader should be operated in ac¬
cord with the proper operating practices as outlined
above. Experimentation and experience on several jobs
will allow the operator to achieve a "feel" for the right
settings for his requirements.
The MASTER LOW FREQUENCY EQUALIZER
(10) is capable of 15 dB boost or cut @ 50 Hz. This
equalizer is similar to those used in the individual
channels and is designed to exhibit a "Shelving"
characteristic which has proven to yield the best results
in this type application. The controls are ‘’flat" with no
boost or cut in the straight up (12 o’clock) position with
boost being obtained in the righthand (clockwise) posi¬
tion. Care should be taken NOT to over-boost with the
master EQ controls Since each channel is equiped with
equalization, it is poor practice to use too much ad¬
ditional boost in this master section. Over-boosting on
low frequencies will impart a boomy and muffled tonali¬
ty to the program material and will substantially
decrease the intelligibility of voices being mixed through
the console
The MASTER HIGH FREQUENCY EQUALIZER
(9) is capable of 15 dB boost or cut @ 10 kHz and is
designee to exhibit a ‘shelving’ characteristic. The
operation of this EQ control is similar to the low EQ with
the exception of the fact that it controls the high fre¬
quency portion of the audio spectrum. Care should be
taken not to over-boost the high frequencies to avoid
undue amp ification ol resicua! system noise (hiss) as
well as creating a "strident" or screechy sounding
system. High frequency over-ooost also tends to create
undue acoustic feedback. When balancing ANY of the
equalizers for proper tonality, you always start with ALL
equalizers in their fiat (12 o'clock) positions and work
from there. After you have spent several hours working
with any particular setup of mics. performers, etc., you
will acquire a good working equalization setup and be
able to achieve the desired tonality.
The important thing to keep in mind about the
equalization on the 900 Mixer is that each channel is
provided with its own set of EQ controls to correct
problems in that particular channel, while Master EQ is
provided to allow for overall tonal balance and feedback
control. We have not included this equalizaiion system
to allow tremendous boost or cut but rather to allow in¬
cremental EQ where it is needed. You must use com¬
mon sense in the use of these controls in order to
achieve satisfactory tonal balance and intelligibility.
The EFFECTS LEVEL (12) is the control that deter¬
mines the overall signal output level for the effects send
buss. This effects buss has two output connectors
associated with it, one is a high level output that can be
used to drive a power amplifier for an additional monitor
system and the other is a low level output designed to
drive the input of an effects device such as an echo unit,
phasor, digital delay line, etc. In addition to driving the
high and low level effects outputs, the effects level con¬
trol also determines the drive to the internal reverb delay
line. This effects level control must be adjusted so that
the output level from the jack on the rear panel does not
overload the input circuitry of the effects unit you are
driving, thus causing clipping or other forms of distor¬
tion. This is especially critical on some of the special
effects units that are designed to work with guitars or
other instruments with relatively low output levels.
The REVERB RETURN (13) is the gain control ele¬
ment for the reverb system. The signal coming from the
reverb delay lines is amplified and Ihe gain or amount of
signal sent to the main summing buss is controlled by
the reverb return.
The REVERB CONTOUR (11) is the control used
to vary the tonality of the reverb signal and is a low cut
type equalizer. This contour control is very useful in
tailoring the reverb sound and in controlling reverb in¬
duced feedback. Balancing these reverb controls will
yield many combinations of reverb delay, tonality, and
sustain.
The EFFECTS RETURN LEVEL (15) control is
provided for varying the input levels mixed into the main
mixing buss from the effects return input jack provided
on the rear panel. The effects return input jack allows
signals from mics or effects units to be patched directly
into the main mixing buss. This control may be con¬
sidered a separate channel whose output is blended
into the main mix just as the individual channels are
The MONITOR MASTER FADER (14) is the output
level control for the main monitor system, The same
operating practices should be observed when using this
control as when using the main channel controls. The
individual channel monitor send controls shouic be set
in such a manner that will allow the monitor master
slider (fader) to be operated somewhere in the middle
of its travel to allow yourseif adequate control margins,
up or down, as might be required on the job. The
monitor output signal is flat, that is, we did not include
equalization for the monitor in the 900 Mixer since this
equalization is usually external to the mixer and is best
performed on the stage itself, which is generally at some
considerable distance from the mixer It is because the
mixer is usually located remotely from the performing
area that it is sometimes difficult for the monitor
equalization to be performed at the mixer.
The METER SET CONTROL enables the VU
meter to be adjusted for proper indication with any
power amplifier tape recorder, or other equipment
driven by the mixer. If your power amp, tape recorder,
etc... has VU meters, the levei set control can be ad-