EQUALIZER
Specifications: 672A Equalizer
All specifications apply when driving 600
ohms or higher impedances. Noise mea-
sured on an average -reading meter through
a20-20,000Hz bandpass filter with 18dB/
octave Butterworth skirts.
Electrical
Input:
Impedance, Load (each leg): 100K in paral-
lel with lOOOpF, electronically balanced
Impedance, Driving: Ideally 600 ohms or
less, balanced or unbalanced
Nominal Input Level: Between -10 and
+4dBm
Absolute Overload Point: +26dBm
Output:
Impedance, Source: 47 ohms in parallel
with lOOOpF, unbalanced (Optional trans-
former balanced 600 ohm outputs)
Impedance, Load: Should be 600 ohms or
greater-will not ring into any capacitive
load
Nominal Output Level: +4dBm
Max. Output Level Before Clipping:
+19 dBm, 20 -20,000Hz
Frequency Response:
10.25dB, 20 -20,000Hz: EQ controls set at
“O” detents
Available Gain:
+12dB; adjustable to —infinity by means
of front -panel GAIN control
Slew Rate:
Varies between 6and 13V/uS depending
upon setting of GAIN control; slewing is
symmetrical. Internal bandlimiting assures
that slew rate limiting will not occur even
with the most severe equalization and pro-
gram material.
Square Wave Response:
Square wave exhibits no spurious ringing at
any output level. The only ringing observ-
able is that theoretically associated with any
given equalization curve.
Total Harmonic Distortion:
Less than 0.05%, 20 -20,000Hz (+18dBm)
SMPTE Intermodulation Distortion:
Less than 0.05% (+18dBm: 60/7000Hz,4:l)
Noise at Output:
Less than -75dBm (EQ in, Filters out,
Controls centered)
Overload /Noise Ratio:
Better than 113dB for any single bandpass
filter, for any settings of TUNING or BAND-
WIDTH controls.
Equalization Ranges:
+16dB peaking EQ, Reciprocal
Tuning Ranges:
20 -60Hz;40 -150Hz; 110-310Hz; 230-
750Hz; 480 -1900Hz; 1.1- 4.5Hz; 2.8-9.0kHz;
5.9 -21kHz. Dials calibrated at ISO preferred
frequencies.
“Q” Range:
Greater than 0.5 to 10 for any setting of the
TUNING control
Low Pass Filter Section:
Tunable in 2ranges: 200 -2000Hz or 2.0-
20kHz, 12dB/octave, (2nd-order
Butterworth)
High Pass Filter Section:
Tunable in 2ranges: 20 -200Hz or 200 -
2000Hz, 12dB/octave, (2nd-order
Butterworth)
Overload Circuit:
Lamp lights for 200mS if the instantaneous
peak output of any amplifier rises to within
ldB of its clipping point.
Circuit Design:
Active RC realized with FET-input opamps.
Line driver employs discrete transistor cur-
rent booster.
Operating Temperature:
0-50°C
Power Requirements:
115/230VAC 110%; 50/60Hz; 6watts
Physical
Operating Controls:
EQUALIZATION, TUNING, and BAND-
WIDTH for each of eight bands. TUNING,
RANGE (xl; xlO), and FILTER IN/OUT
for each filter. EQUALIZATION IN/OUT,
POWER ON/OFF, and GAIN for entire
equalizer.
Panel:
19” x5V4” (48.3 x13.3cm): 3units
Chassis Depth Behind Panel:
51/4”(13.3cm)
Weight:
Net: 8lbs. (3.6kg); Shipping: 12 lbs. (5.4kg)
AC Cord:
3-wire U-ground to USA Standard
Connectors:
140 type barrier strip (#5screw) plus paral-
lel-wired V4” 3ckt. phone jacks (Switchcraft
12B or equal). Holes punched for XLR-type
connectors (Switchcraft D3F and D3M or
equal)
Circuit Ground:
Available on barrier strip; normally jumpered
to chassis.
Specifications subject to change without notice.
