14
FEATURES AND CONTROLS
3-Band EQ
The PPM Series has 3-band equalization at
carefully selected points —
LOW
shelving at
80Hz,
MID
peaking at 2.5kHz, and
HI
shelving
at 12kHz. “Shelving” means that the circuitry
boosts or cuts all frequencies past the specified
frequency. For example, rotating the
LOW EQ
knob 15 dB to the right boosts bass starting at
80Hz and continuing down to the lowest note
you ever heard. “Peaking” means that only a
selected band of frequencies surrounding a
center frequency is affected by the EQ control
— the frequencies around 2.5kHz in this case.
LOW EQ
This control gives you up to 15 dB boost or
cut at 80Hz and below. The circuit is flat (no
boost or cut) at the center detent position.
This frequency represents the punch in bass
drums, bass guitar, fat synth patches, and some
really serious male singers.
MID EQ
Short for “midrange,” this knob provides
12 dB of boost or cut, centered at 2.5kHz, also
flat at the center detent. Midrange EQ is often
thought of as the most dynamic, because the
frequencies that define any particular sound
are almost always found in this range. You can
create many interesting and useful EQ changes
by turning this knob down as well as up.
HI EQ
This control gives you up to 15 dB of boost
or cut at 12kHz and above, and it is also flat at
the detent. Use it to add sizzle to cymbals, and
an overall sense of transparency or edge to key-
boards, vocals, guitar, and bacon frying. Turn it
down a little to reduce sibilance, or to hide
tape hiss.
Moderation during EQ
With EQ, you can also screw things up roy-
ally. We’ve designed a lot of boost and cut into
each equalizer circuit because we know every-
one will occasionally need that. But if you max
the EQs on every channel, you’ll get mix mush.
Equalize subtly and use the left sides of the
knobs (cut), as well as the right (boost).
EFX
MON
HI
12kHz
MID
2.5kHz
LOW
80Hz
PAN
VOLUME CH.
1
INPUT
LEVEL
SET
MIC
1
INSERT
LINE
U
O
O
+10
U
+15
-15
U
+15
-15
U
+12
-12
1
U
+20dB
O
O
HI
LOW
NORMAL
U
O
O
+15
R
L
Stereo Version
Channel Strip
Channel Strip Description
INPUT LEVEL SET
If you haven’t done so already, please read
the “Level-Setting” procedure on page 6.
The
INPUT LEVEL SET
control adjusts the
input sensitivity of the mic and line inputs (on
channels 7 & 8 it affects only the mic input).
This allows signals from the outside world to be
adjusted to optimal internal operating levels.
To correctly adjust the
INPUT LEVEL SET
control, apply a signal to the channel and turn
up the
INPUT LEVEL SET
control until the LED
next to it just begins to blink. This provides the
best signal-to-noise ratio for the channel.
VOLUME
The rotary
VOLUME
knob controls the
channel’s level…from off to unity gain at the
center detent, on up to +20 dB of additional
gain when turned all the way up. The
VOLUME
control is equivalent to a channel fader.
These are mono controls except on chan-
nels 7 and 8 of the 408S and 808S models,
which use stereo controls.
Unity gain means there is no
change in signal level. In
other words, the signal enter-
ing the control is the same
volume (or in this case, the
same voltage level) as the signal leaving the
control. Once you have adjusted the
INPUT
LEVEL SET
controls on all the channels, you
can set the remaining controls to their unity
(
U
) positions and your signals will travel
through the mixer at optimal levels. What’s
more, all the labels on our level controls are in
decibels (dB), so you’ll know what you’re doing
level-wise if you choose to change a control’s
settings.
PAN
This control appears on the stereo models
(408S and 808S).
PAN
adjusts the amount of
channel signal sent to the left versus the right
outputs. On the mono channels 1-6 these con-
trols act as true pan pots. On the stereo
channels 7 and 8, the
PAN
knob acts like the
balance control on your home stereo.
