Manual-3
In and Out Level controls
LEVEL
controls serve three purposes, with the assistance of the
In
and
Out Meters
:
1. Adjust the
IN
signal level for good headroom and signal-to-noise.
2. Adjust the
OUT
signal level to compensate for changes in signal level due to filter boost/cut
settings.
3. Adjust sensitivity. The operation of the OUT LEVEL control is reversed from the IN LEVEL.
Pushing the control
up
reduces
gain. Pushing the control
down
increases
the gain. To easily
adjust sensitivity without affecting the output signal level, grasp the IN and OUT controls and
move them together. Only the A-channel IN and OUT LEVELs are active in 10-BAND mode.
In and Out Meters
IN
and
OUT Meters
are peak responding and indicate signal level in dBu.
Peak-dBu is held and displayed for 2 seconds. Attack is instantaneous. Decay is 500
ms for a 20 dB step. A and B meters remain active in linked 10-band mode.
EQ Bypass
BYPASS
switches have two modes of operation. If the rear
panel switch is set to
BYPASS ALL
, all filters
and
level controls
are bypassed. If this switch is set to
BYPASS FILTERS
,
only
the filters are bypassed. Filters include Parametric, Tone and
Cut. An automatic relay bypass hardwires the Inputs to the
Outputs when the
POWER
is off.
A / B control switches
A / B
switches determine which set of
controls
is used by channel A and channel
B. There is a 100 ms mute to allow the filters to settle when the A/B control switch
is changed. The only control
not
affected by the A / B switches is BYPASS. A / B
control switches allow:
• Independent, dual mono operation
• A/B setting comparison
• 5-Band linked stereo operation (A or B controls affect both channels)
• Two “analog memories”
See the Applications section for example uses of the A / B switches.
10-Band mode / 5-Band mode
In
5-BAND
mode, the PEQ 55 provides two independent 5-band parametric equalizers. A
or B controls may be used to control each channel as described above. In
10-BAND
mode, both
channels are stereo linked and operation is as follows:
1. All 10 filters affect both A and B Outputs, permitting mono or stereo linked operation.
2. Meters remain independent and active for both channels.
3. Channel A and B BYPASS switches remain active.
4.
A1
LOW SHELF and
B5
HIGH SHELF modes are available.
(A5 high-shelf and B1 low-shelf filter modes are disabled.)
5. Channel A TONE, CUT FILTERS and LEVEL controls are active.
(Channel B tone, cut-filter and level controls are disabled.)
6. A / B control switches are inactive.
7. The Outputs mute for 200 ms when switched between 10-BAND and 5-BAND modes.
FILTERS
ALL
BYPASS
(rear panel switch)
PARAMETRIC
EQUALIZER
∞
∞
∞
∞
6
6
20k
7k
14k
5k
10k
15
120
30
240
60
6
6
20k
7k
14k
5k
10k
15
120
30
240
60
+6
-12 -6
-3
0
+3
+12 OL
12
12
12
12
12
12
12
12
+
+
0
+
0
+
0
0
+
+
0
+
0
+
0
0
+6
-12 -6
-3
0
+3
+12 OL
2
oct
dB
1
.5
1.5
Hz
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
2
1
.5
1.5
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
oct
dB
Hz
2
oct
dB
1
.5
1.5
Hz
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
2
1
.5
1.5
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
oct
dB
Hz
2
oct
dB
1
.5
1.5
Hz
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
2
1
.5
1.5
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
oct
dB
Hz
2
oct
dB
1
.5
1.5
Hz
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
2
1
.5
1.5
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
oct
dB
Hz
2
oct
dB
1
.5
1.5
Hz
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
2
1
.5
1.5
125
500
250
2k
1k
1
/
12
12
0
-6
6
-24
oct
dB
Hz
PEQ 55
BYPASS
GAIN
BW
LOW SHELF
x1
x10
x0.1
FREQUENCY
A1
LOW MID HIGH
LOW HIGH
IN
OUT
POWER
B
EQ
5-BAND
OUT
IN
10-BAND
BYPASS
A
CUT FILTERS
TONE
LEVEL
CUT FILTERS
TONE
LEVEL
A
B
EQ
OUT
IN
BYPASS
A
B
OL
OL
BYPASS
GAIN
BW
LOW SHELF
x1
x10
x0.1
FREQUENCY
B1
BYPASS
GAIN
BW
HIGH SHELF
x1
x10
x0.1
FREQUENCY
A5
OL
OL
BYPASS
GAIN
BW
HIGH SHELF
x1
x10
x0.1
FREQUENCY
B5
BYPASS
GAIN
BW
x1
x10
x0.1
FREQUENCY
A2
OL
OL
BYPASS
GAIN
BW
x1
x10
x0.1
FREQUENCY
B2
BYPASS
GAIN
BW
x1
x10
x0.1
FREQUENCY
A3
OL
OL
BYPASS
GAIN
BW
x1
x10
x0.1
FREQUENCY
B3
BYPASS
GAIN
BW
x1
x10
x0.1
FREQUENCY
A4
OL
OL
BYPASS
GAIN
BW
x1
x10
x0.1
FREQUENCY
B4
The active control surface for 10-BAND mode. Inactive controls are grayed out.