Peavey 900 - Page 3

The MONITOR SEND CONTROL (2) is the
channel mixing element for determining the all-
important monitor mix. The signal for the monitor send
is obtained right after the input preamp and before the
channel EQ. This is referred to as a Monitor Pre-send
Control, i e.. it is betore or pre to the channel equaliza¬
tion and slider level control. This makes it independent
of these controls, meaning that any changes made to
the EQ or channel level will not affect the monitor
system. Having the monitor send with the pre capability
is absolutely VITAL to avoid feedback of the monitor
system when EQ and normal incremental output
variations are made in the channel fader during the
course of the performance.
EQUALIZATION - The equalization circuitry of the
900 Mixer is the latest active type utilizing negative feed¬
back technology. We selected circuitry that produces a
“shelving" type of action because the conventional type
circuitry used by some manufacturers tends to create
erratic, or sometimes harsh sounding results when in
the near-maximum boost positions. These two
equalization controls will produce extremely smooth ac¬
tion as wei: as giving effective tone control. Experience
will show their utility in achieving professional channel
equalizaiton on the job.
It should be remembered lhat these active
equalization circuits are a form of “electronic crossover"
in which the equalizaiton controls are similar to level
controls for their respective frecuency bands.
Generally, it is poor operating practice to use Doth
equalizer controls in the deep cut (counter-clockwise)
positions since this results in substantially lower gam
from the channel. It should be remembered that the
balance of highs and lows is a relative situation, cutting
overall channel gain should properly be done by the
output slide attenuator or input attenuator.
The LOW "REQUENCY EQUALIZER (4) is
capable of better than 15 dB boost or cut (§) 100 Hz with
a sloping characteristic exhibited up to the crossover
point. The shelving action of this control has proven to
yeild a much more satisfying and effective equalizat on
characteristic than some of the "wide open” equaliza¬
tion circuits claiming 20-25 dB boost and cut. The ac¬
tion ol this equalizaiton control is conventiona and
should present no problem in operation. Boost is ob¬
tained in the righthand (clockwise) postion while cut s
obtained in the lefthand (counier-clocxwise) position.
The vertical (12 o’clock) position yields a flat (no boost
or cut) response and is the position from which all tonal
balancing should be started.
The HIGH FREQUENCY EQUALIZER (3) is
capable of 15 dB boost or cut @ 5 kHz with a shelving
characteristic s oping down to the crossover point, i he
boost or cut action oT this control is very s.milar to that of
the low equalizer with the exception of its high irequen-
cy eflect. Boost is obtained to the right of the center
position. Flat response is obtained in the center (12
o’clock) position.
Caution should be exercised in using extreme cw-
frequency boosl to avoid empnasing objectionable
wind no ses or rumble from the microphone as well as
any hum that might enter the mixer from external
sources. Excessive treble boost shouic be avoided to
keep residual noise from the amplification circuitry to a
reasonable leve as well as to'avoid a strident or
screeching tonality in the output program material
in sound reinforcement, there is notning holy
about an entirely flat equalization setting, if it is
necessary to use moderate amounts of equalization,
then you should be willing to do so. considering that the
"ideal ’ Hat settings are almost never used, even in the
recording studio, and even less often in most sound
reinforcement applications.
The EFFECTS SEND CONTROL (5) is the channel
level for determining the amount of signal from each
respective channel to be sent to the effects output or to
be mixed into the reverb summing buss. The effects
send circuit has been designed to provide multiple
functions which will be explained further in the master
control section.
The CHANNEL ATTENUATOR SLIDER (6) is the
output level control that determines the mix into the
main summing buss. Its calibration is in decibels of
attenuation and this is why the numbering sequences
goes from off (infinity = oo). or maximum attenuation to
zero (0). or no attenuation. RememDer that attenuation
is the cutting or reduction of the signal level i.e.. the
more attenuation, the more you have cut down the
signal level. The output fader is calibrated in accor¬
dance with standard practice for professional audio
equipment.
Proper setting of the input attenuator (pad) should
produce adequate gain within the input preamp to allow
slider settings approximately in the center (ap¬
proximately -20 dB). You should also remember that
the input attenuator is a kind of pre gain control and ts
settings will most definitely influence the settings for the
output slider with any given input signal The input
attenuator should be adjusted for the maximum gain
that will allow distortion free performance, then the out¬
put slider level should be adjusted for proper mix.
It is very poor operating practice to use the input
pads in the extreme cut positions and then have to sei
the output s:iders in their close to maximum positions to
obtain adequate channel output. This type of operation
results in less than optimum signal-to-noise ratios as
well as contributing to headroom problems. As with any
system, "common sense" must be combined wifi'
operating knowledge to produce satisfactory results.
Overall, the channel controls should be set to provide a
reasonable amount of “adjustment" i.e., none of the
gain controlling elements (input attenuator/output
slider) should be operated near their extreme up or
down positions. After several hours usage, the operator
will have acquired a good "feel" for the characteristics
of the controls and should be able to suitably handle
any mixdown situation encountered in the field with
satisfactory results.
MASTER AREA - The master area of the 900 Mix¬
er contains all the master or final output controls for the
mixing busses. The main mixing buss equalization
features shelving type high (9), and low (10) EQ. The
Effects level (12) is the master control lor the effects
mixing buss
The master level controls (7) (14) of the 900 Mixer
should be set in such a manner that they are close to the
center of their travel to take advantage of maximum
control action. It is poor practice to run the channel
faders up near maximum and ihen run the main taders
near the low end to achieve the desired output levels.
Operation in this manner will cause the operator to lose
his "range" in control action with all the gain located in
one element while the other is nea r its stop position.
Best practice calls for most controls to be operatec in
the middle of their operating range to allow maximum