Publication ©1997 Symetrix, Inc.
Symetrix, Inc. • Lynnwood, WA USA • Tel 425-787-3222 • Fax 425-787-3211 • www.symetrixaudio.com
Symetrix, Inc. • Lynnwood, WA USA • Tel 425-787-3222 • Fax 425-787-3211 • www.symetrixaudio.com
Symetrix, Inc. • Lynnwood, WA USA • Tel 425-787-3222 • Fax 425-787-3211 • www.symetrixaudio.com
Symetrix, Inc. • Lynnwood, WA USA • Tel 425-787-3222 • Fax 425-787-3211 • www.symetrixaudio.com
Symetrix, Inc. • Lynnwood, WA USA • Tel 425-787-3222 • Fax 425-787-3211 • www.symetrixaudio.com
551E Five Band Parametric EQ
The Parametric Equalizer (EQ) shall be a
single channel unit that shall provide five
independent bands of proportional-Q type
filtering. There shall also be separate high-
pass and low-pass filters. The unit shall
occupy one rack space (1U).
The EQ shall incorporate five identical filter
bands. Each band shall have the following
controls and control ranges: a cut/boost
control with a -20 dB - +12dB range, a
frequency sweep control with a 100 Hz -
2kHz range, a frequency range multiplier
switch with X10, X1, and X.1 settings, and
a bandwidth control with a .05 octave - 2.0
octave range. There shall also be a 12 dB/
Oct high-pass filter with a user adjustable
cutoff frequency range 1Hz to 250 Hz, and
551E ARCHITECTS AND ENGINEERS SPECIFICATIONS
SPECIFICATIONS
Input/Output
Maximum Input Level
+22 dBu Balanced
Maximum Output Level
+22 dBu Balanced, +18 dBu Unbalanced
Input Impedance
20k Ohms Balanced, 10k Ohms Unbalanced
Output Impedance
300 Ohms Balanced, 150 Ohms Unbalanced
Performance Data
Frequency Response
+0 dB, -3 dB (20 Hz to 62 kHz)
Dynamic Range
>114 dB
Signal to Noise Ratio
>96 dB (unweighted, ref to +4 dBu, eq in, all bands flat)
THD+Noise (1 kHz at +4 dBu)
<0.002% (<10 Hz to 30 kHz measurement bw,
eq in, all bands flat)
EQ Band Control
Frequency Control Range
10 Hz - 20 kHz (inc. Frequency Switch)
Cut/Boost Range
-20 dB, +12 dB
Bandwidth
.05 oct - 2.0 oct
input signal of +22 dBu and have a
maximum output level of greater than +22
dBm. There shall be a front panel clip
indicator that will illuminate at 1dB below
clipping. It shall monitor the input, output
and each EQ band.
The inputs shall be direct coupled, active
balanced designs terminated with 3-pin
XLR (AES/IEC standard wiring), and ¼"
TRS female. The input circuitry shall
incorporate RFI filters. There shall be a
servo-balanced, direct-coupled output that
shall terminate in 3-pin XLR (AES/IEC
standard wiring) and ¼" TRS.
The EQ shall be capable of operating by
means of its built-in power supply
Specifications subject to change without notice.
a 12 dB/Oct low-pass filter with a cutoff
frequency range from 2.5 kHz to 60 kHz. A
front panel input level control shall provide
±15 dB of gain adjustment.
When the unit is inoperative (either by loss
of power or via the BYPASS switch), the
inputs and outputs will be wired together
by a relay.
The frequency response with all filter
bands flat, EQ in, high-pass and low-pass
set to the outside extremes of their ranges
shall be 20Hz - 62 kHz (+0, -3dB). The
total harmonic distortion plus noise shall
be less than 0.002% (EQ in, all bands flat).
The dynamic range shall be greater than
114 dB. The EQ shall accept a maximum
connected to 117V nominal AC, 95-130V,
50-60 Hz (230V nominal AC, 165-255V, 50
Hz where applicable). Power consumption
shall be 15 watts maximum. There shall be
a rear panel receptacle for an IEC type
detachable power cord. The EQ shall be UL
and CE approved.
The unit shall be a Symetrix Incorporated
model 551E Five Band Parametric
Equalizer.
551E
E
LYNNWOOD, WA, USA
MANUFACTURED IN
FIVE BAND PARAMETRIC EQUALIZER
INPUT
OUTPUT
BALANCED/
UNBALANCED
BALANCED
BALANCED
1
2
3
INPUT
BALANCED/
UNBALANCED
551
TIP = HIGH(+) = PIN 2
2
1
3
OUTPUT
RING = LOW(-) = PIN 3
SLEEVE = GND = PIN 1
RING
TIP
SLEEVE
PERSONNEL.
TO QUALIFIED SERVICE
PARTS. REFER SERVICING
NO USER SERVICEABLE
THIS UNIT CONTAINS
15 WATTS
MAXIMUM
AC INPUT
FABRIQUÉ AUX E.-U. PAR SYMETRIX INC., LYNNWOOD, WASHINGTON.
RÉFÉREZ TOUTE RÉPARATION À UN TECHNICIEN QUALIFIÉ.
TYPICAL BALANCED CONNECTIONS
Cut Filters
Low Cut Filter Slope
12 dB/octave
Cutoff Frequency Range
6 Hz - 260 Hz
High Cut Filter Slope
12 dB/octave
Cutoff Frequency Range
3 kHz - 65 kHz
Physical
Size (hwd)
1.72 x 19 x 8.25 inches, 4.37 x 48.26 x 20.955 centimeters
Shipping Weight
8 lbs, 3.64 kg
Electrical
Power requirements
117V nominal, 95 to 130V AC, 50 to 60 Hz, 15 watts
230V nominal, 165 to 255V AC, 50 Hz, 15 watts
