Symetrix 551E, Руководство пользователя

Страница: 6 / 22

4
551E
552E
/
Front Panel Controls Chapter 4
Input Level
Use this control to adjust the input sensitivity
by ±15 dB. Since the 551E/552E’s input has 18
dB of headroom above +4dBm, the unity gain
position (12:00) should work for normal
operating conditions. However, if you apply
extreme amounts of EQ boost or find that the
input signal level is too high (the clip LED will
illuminate), you may need to increase your
input headroom. Do this by turning the knob
counterclockwise to attenuate the input signal.
If you find that the input signal is very low (the
output of a -10 device is a good example), turn
the input level control clockwise to boost the
level of the signal going through the 551E/552E.
This will optimize the signal-to-noise ratio.
Figure 1 - Partial view of front panel controls.
Diagram 2 - Low cut filter with
12 dB per octave.
AUDIO PRECISION 551E vs 23 MAY 96 10:49:15
-20.00
-15.00
-10.00
-5.000
0.0
5.0000
10.000
15.000
20.000
AMPL(dBu)
20 100 1k 10k 20k
FREQ(Hz)
Bypass Button
Push this button into the ACTIVE position to
engage the 551E/552E’s circuitry. The BY-
PASS (out) position shunts the input signal
directly from the input jacks to the output
jacks via a relay. There are no passive or
active components in the signal path in this
mode.
Note: The relay mechanism is also engaged
when the AC power is disconnected,
enabling the unit to pass signal even
when the power is off.
HIGH CUT
42K
115
5K
18K
3K 65K
SYSTEM
LOW CUT INPUT
LEVEL (dB)
8
U
50 22
E
ACTIVE
BYPASS
260 6 +15 -15
POWER CLIP
551
EQUALIZER
PARAMETRIC
FIVE BAND
CUT BANDS
[With the exception of Chapters 9 and 10, all text in this User's Guide is applicable to both the
551E and the 552E. For brevity we will use the name “551E/552E” to refer to both units.]
Low Cut Filter
Diagram 2 illustrates a 12 dB
per octave low frequency
roll-off filter. Use this to
protect subwoofers in
sound systems, clean-up
muddy recordings, or
increase speech intelligibil-
ity in announce systems.
The frequency range is 6Hz
(essentially this is bypass)
to 260 Hz.
System Controls
Cut Band Controls