Page 1
FIGURE A. SR106 FRONT PANEL
Temperature Range:
................ Operating - 7" to 57°C (20" to 135°F)
Storage
.............. _ - 29" to 71 "C (-20" to 160°F)
Dimensions
................ 44.5 mm height x 483 mm width
x 216 mm depth (1% in. x
19 in. x 8% in.)
........................ Weight 3 kg (6 Ib, 8.8 oz)
Finish
.......................... Matte black
Installation
.................. Equipped for standard 483 mm
(19 in.) audio rack mounting;
may be operated in optional
A30A or A105A Carrying Case
(with other equipment)
Certifications
.............. ~isted by Underwriters' Labora-
tories, Inc.; listed by Canadian
Standards Association as cer-
tified
(SR106 only)
OPERATING INSTRUCTIONS
Functional Description (Refer to Figures A and B)
1. Power-On Indicator Lamp-Indicates ac power
is being applied to unit.
2. POWER ON-OFF Switch-Controls ac power to
unit.
3. LlNE LEVEL
OUTPUTS/LOW FREQUENCY 3-
Pin Male Connector-Provides low-frequency
balanced output connection to power amplifier.
May be unbalanced externally.
4. LlNE LEVEL
OUTPUTS/LOW FREQUENCY
Phone Jack-Provides low-frequency balanced
or unbalanced output connection to power am-
plifier.
5. LlNE LEVEL
OUTPUTS/HIGH FREQUENCY
Phone Jack-Provides high-frequency balanced
or unbalanced output connection to power am-
plifier.
6. LlNE LEVEL
OUTPUTS/HIGH FREQUENCY 3-
Pin Male Connector-Provides high-frequency
balanced output connection to power amplifier.
May be unbalanced externally.
7. CROSSOVER FREQUENCY Slide Switch-
Selects crossover frequency of 500 Hz, 800 Hz or
2600 Hz for separation of high- and
low-
frequency signals to power amplifiers.
8. LlNE LEVEL INPUT 3-Pin Female
Connector-
Provides balanced bridging, high-impedance in-
put connection from audio console or mixer-
preamplifier. May be unbalanced externally.
9. LlNE LEVEL INPUT Phone Jack-Provides ba-
lanced or unbalanced bridging, high-impedance
input connection from audio console or mixer-
preamplifier.
10. Ac Grounded Line Cord-Connects unit to ac
power source
(SR106 only).
11. AC (MAINS) POWER 3-Pin Connector-Con-
nects unit to ac (mains) power source via
supplied line cord
(SR106-2E only).
12. VOLTAGE SELECTOR Slide Switch-Selects
115V or 220V input power
(SR106-2E only).
General Operating Instructions
WARNING
To reduce the risk of fire or electric shock,
do not expose this appliance to rain or
extreme moisture.
1. Using hardware provided,
install
SR106 securely
in 483 mm (standard 19 in.) rack or optional
A30A or A105A Carrying Case prior to making
electrical connections.
2. Connect SR106 LlNE LEVEL OUTPUT/LOW FRE-
QUENCY 3-pin connector or phone jack (3,
4)
to (low frequency) power amplifier line level
input.
3. Connect
SR106 LlNE LEVEL OUTPUT/HIGH FREQUENCY &pin connector or phone jack
(5, 6) to second (high frequency) power amplifier
line level input.
4. Connect audio
console or mixer-preamplifier line
level output to
SR106 LlNE LEVEL INPUT &pin
connector or phone jack (8, 9).
5. Make sure speaker systems are properly con-
nected to power amplifiers and are adjusted
for biamplified operation.
MTIM if(TOR t
rr rolula 3 whr
II SR106-2E ONLY 12 10 3 7 8 9
FIGURE B.
SR106 REAR PANEL
Page 2
6. Move CROSSOVER FREQUENCY Switch (7) to
select proper crossover frequency (see Speaker
Operating Instructions).
7. (SR106-2E only) Move VOLTAGE SELECTOR
Switch (12) to 115V or 220V position as desired.
8. Connect ac line cord to grounded 108- to
132- volt (SR106), or 105-1 25V or 210-250V (SR106-
2E), 50/60 Hz ac source.
9. Turn on front-panel POWER ON-OFF Switch (2).
Red indicator lamp (1) will go on, indicating
power application. The
SR106 is now operating.
1
@. Adjust audio console or mixer-preamplifier and
power amplifier controls for desired operating
levels.
Mounting and Ventilation
The SR106 Electronic Crossover is designed for
rack-mounting in a 483
mm (standard 19 in.) audio
equipment cabinet rack and is supplied with the nec-
essary mounting hardware (see Figure C). If possible,
the
SR106 should be rack-mounted below its asso-
ciated power amplifiers.
The
SR106 may also be operated while mounted in
a Shure
A30A or A105A Carrying Case. The A30A has
a panel height capacity of 88.9
mm (3Y2 in.), pro-
viding space for two
SRlOG's, or one SR106 and
one other unit of 44.5 mm
(1% in.) height. The
A105A has a panel height of 178 mm (7 in.), providing
space for up to four SRlO6's, or one SR106 and
other equipment totaling 133.4 mm
(5Y4 in.) in height.
No special precautions are required for ventilation.
The
SR106 may be operated over a temperature range
of
- 7" to 57°C (20" to 135°F) in continuous duty with-
out derating.
483 mm (19 1N!
-44 4 mrn(1-3/4 IN,
'NOT lNCLUDlN6 CABLE/CONNECTOR CLEARANCE DEPTH
FIGURE C.
OVERALL DIMENSIONS
Power Supply
The SR106 is furnished with a three-conductor power
cable and three-prong grounded plug (10). Connect the
SR106 to
an outlet which supplies 108 to 132 volts
ac, 50/60 Hz power. Maximum power consumption at
120 volts under normal operating conditions is 3 watts
(0.025 amperes at 120 volts). If extension cords are
required, a high-quality, 18-gauge or larger cord should
be used.
The
SR106-2E is furnished with a three-conductor
line cord without a power plug. Obtain a suitable 3-pin
male power plug and attach it to the line cord. The
plug should be installed by qualified service personnel.
(Brown lead goes to "hot" or "live" terminal, blue lead
to neutral terminal, and
greenfyellow lead to ground
or earth terminal.) Select proper operating voltage
(115V for 105-125V supply or 220V for 210-250V supply)
using the VOLTAGE SELECTOR Switch (12).
A POWER ON-OFF toggle switch on the front panel
(2) controls the application of ac power to the
SR106,
and a red indicator lamp (1) indicates the power-on
condition. The tamper-proof cover supplied
(SR106
only) may be used to eliminate accidental movement
of this switch.
Functional Circuit Description
The inputs of the SR106 Electronic Crossover con-
sist of one phone jack (9) and one three-pin female
audio connector (8) (see Figure
D). The phone jack is
a three-circuit (stereo) type and is wired in parallel
with the three-pin connector to provide a balanced in-
put with either connector. The input signal then passes
through a 6 dB
stepdown input isolation transformer
to a unity-gain buffer amplifier.
The next stage is a 12
dB/octave high-pass filter
with an operating frequency of 500 Hz, 800
Hz or 2600
Hz. All frequencies above the selectable operating fre-
quency are routed to a unity-gain filter amplifier stage.
One output of this stage goes to a 6 dB gain, 600-ohm
line driver, which drives the high-frequency output
transformer to
+I8 dBm. The other output goes to
a differential
amplifier/line driver stage, which also
receives an input from the first buffer amplifier stage.
The differential
amplifier/line driver stage thus de-
rives the low-pass signal by responding to the differ-
ence between the buffer amplifier signal (all-pass) and
the filter circuit signal (high-pass). The difference
signal
ampli.tude rolls off at 6 dB/octave. The differ-
ence signal is amplified and drives the low-frequency
output transformer. The resulting frequency response
curves are shown in Figure E. Adding the two outputs
out-of-phase provides a flat output response from 20
to 20,000
Hz. High- and low-frequency outputs appear
on both phone jacks and three-pin, professional, male
audio connectors.
HIGH-PASS FILTER
HIGH FREQUENCY LlNE LEVEL INPUT - - - - - - - - - - - - - - - - - 1 LINE LEVEL OUTPUTS
LOW FREQUENCY LlNE LEVEL OUTPUTS
FIGURE D.
BLOCK DIAGRAM
