Shure SR-109 Service manual

Page 1
SR109
Professional Mixer
OPERATION AND SERVICE MANUAL
Manufactured
SHURE BROTHERS
222
Evanston, Illinois
by
60204
INC.
U.S.A.
WARNING
To reduce the risk of fire or electric shock, do not
expose this appliance to rain or extreme moisture.
Copyright 1979, Shure Brothers Inc. 27A1413 (SG)
Printed in
U.S.A.
Page 2
SR109
Professional Mixer
SPECIFICATIONS
Equipment Type
Number of
lnput Channels Power Output Voltage Gain
Program
Headphones
Link
Accessory
Frequency Response
lnput Sensitivity
Distortion
Noise
(300 Hz-20 kHz)
Hum and Noise
(20 Hz-20 kHz)
'Measurement
kilohms
LINK INPUT
600
oh&,
in
up; all
PROGRAM
8
ohms:
other
nated
full
. . . . . . .
.
. .
. . . . . . .
*
-
. .
. . . . .. .
. . . . .
. . . . . .
. . . . . . . . . .
. . .
conditions:
through
MIC
MASTER
controls
All silicon transistor mixer/pre-
amplifier
. .
.
.
.
8
+19 dBm (program line level)
.
. .
.
.87 -13 dB MIC input to LlNE
LEVEL out
-+3 dB LlNE input to LlNE
37
LEVEL out
-13 dB MIC input to MIC
37
LEVEL out
.
. .
.69 -13 dB MIC input to PHONES
out
. .
.
.54.5 k3 dB MIC input to LlNK
OUTPUT (with 600-ohm termi­nation)
k2 dB LlNK INPUT to LlNE
27
LEVEL output
.59 t3 dB MIC input to ACCES-
SORY output (via pins PUTS)
54.5
k3 dB MIC input to AC­CESSORY output (via pin 9/PROGRAM) (terminated with 600 ohms)
.
. .
k3 dB, 20 Hz-20 kHz (150-ohm
source; 600-ohm load)
.0.1 mV max. for
output
.
.THD less than 1% at +12 dBm,
30 Hz-20 kHz; IM distortion less than
1% at +12 dBm
. .
.
.
.
-
128 dBV (equivalent input noise at full gain)
dBm output noise (MAS-
TER Volume Control down)
dBm output noise (MAS­TER and one channel Volume Control up)
125 dBV (equivalent input hum and noise at full gain)
dBm output noise (MAS­TER Volume Control down)
dBm output noise (MAS­TER and one channel Volume
Control up)
through
ohms
PROGRAM
terrhinated
Channel
0
or
out.
. .
MIC
LEVEL Volume,
and
-72.8
-38.8
.
-
-61.8
-34.8
input
600
switches
150
in
Volume
ohms,
LlNE
150
+4
dBm program
LINE
input
LEVEL
ohms,
PHONES
and
PHONES
1-8/IN-
through
terminated
termi-
Controls
Signal to Noise
(20 Hz-20 kHz)
lnput Attenuation lnput Clipping Level
at 1 kHz:
MIC lnput
LlNE lnput
lnput Common
Mode Rejection
Low-Frequency
Equalization
High-Frequency
Equalization
Tone Oscillator
lnput Impedance at
1 kHz:
Microphone Line (channels
and 8) Link lnput
Output Impedance:
Program
33
in
.
.
. . .
. . . .
. . . . . . .
. . . . . .
.
. . .
. . . . . . .
. .
. . . . .
. . .
.
. . . .
.
. . .
.
.
.
.
.
. . . . .
.Typically 83 dB at maximum out-
put with one channel Volume Control and MASTER Volume Control set at 8 (approximate­ly 58 dB gain)
.
.
0, 15 dB (switch-selected)
.
100 mV (ATTENUATOR out; Ch.
Volume at 2)
4.5
mV (ATTENUATOR out; Ch.
Volume at 12)
0.56V (ATTENUATOR in; Ch. Volume at 2)
mV (ATTENUATOR in; Ch. Vol-
25
ume at 12)
.
.33V (ATTENUATOR out; Ch. Vol-
ume at 2)
1.35V (ATTENUATOR out; Ch. Volume at 12)
90V (ATTENUATOR in; Ch. Vol-
ume at 2)
8.OV (ATTENUATOR in; Ch. Vol-
ume at 12)
.I00 dB at 100 Hz
.
213 dB at 100 Hz with respect to
0 (flat) setting
.
212 dB at 10 kHz with respect
0 (flat) setting
to
1 kHz; less than 1% distortion;
variable level
.
. .
.2.1 kilohms balanced (for use with
25- to 600-ohm microphones)
7
. . .
.
66 kilohms balanced bridging
.
.
.
.35 kilohms unbalanced
Balanced line level: 120 ohms ac-
tual (for use with 25- to
ohm inputs)
Microphone level: 0.5 ohms ac-
tual (for use with 25- to ohm inputs)
600-
600-
Page 3
SR109
Professional Mixer
SPECIFICATIONS
Headphones
..........
Link Accessory
Limiter
Threshold
(adjustable)
Range
Link Jack System
VU Meter Calibration
Phasing (polarity) .Pin 3 of INPUT connectors in
............
...
.3.5 ohms actual (for use with 4- to
16-ohm headphones)
.600 ohms (actual)
......
Unbalanced aux level: 33 ohms
actual (for use with 4K or higher loads)
.....
.Typically -20 to +20 dBm (at
LlNE LEVEL output)
.Approximately 30 dB
......
External signal conditioning out-
put/input; high-level auxiliary amplifier and tape recorder sig­nal output; multiple Mixer con-
nection (common mix); remote master volume control
...
0, f4, +8 dBm, switch-select-
able (0.775, 1.23, 1.95 Vrms) at 1 kHz to 600-ohm load. [VU
RANGE Switch in provides (0.775 Vrms) to 600-ohm load1
0 VU reading of 0 dBm
....
phase with pin 9 of ACCESSO­RY OUTPUT, tips of OUTPUT and PROGRAM LlNE LEVEL OUTPUTS, and pin 3 of
PROGRAM
MIC LEVEL OUTPUTS (PHASE Switch in of ACCESSORY OUTPUT out of phase with the above.
LlNE LEVEL and
0" position). Pins 1-8
0 position
LINK
Phase Switch Output polarity-reversing switch
30 Vdc Bus .Pin 10 on ACCESSORY OUTPUT
Operating Voltage
Power Consumption
Temperature Range:
Operating Storage
Dimensions..
Installation
Weight 7.7 kg (17 Ib) Finish
Certifications Listed by Underwriters' Labora-
...............
................
.........
.........
.90-132 Vac, 50/60 Hz (SR109)
....
90-132, 180-250 Vac, 50/60 Hz
...
20 watts max. (Mixer only). 500
-7O to 54OC (20' to 130°F)
......
.......
.........
...........
.........
.-29O to 71°C (-20' to 160°F)
133 mm H
Equipped for standard 19 in. (483
Matte black, with beige write-on
(0°, 180') (reverses phase of all program outputs)
connector is regulated +30
k3.5 Vdc supply; pin 11 is ground (earth). May be used to power accessories up to 50
mA.
(SR109-2E)
watts max. (SWITCHED AC re-
ceptacle)
mm D (See Page 4.)
(51/4 in. x 19 in. x 9% in.)
mm) rack mounting; (133 mm) height; may be oper-
ated in accessory
rying Case or in custom control center.
trim strip
tories, Inc.; listed by Canadian
Standards Association as cer-
tified
(SR109 only)
x
483 mm W X 232
(SR109 only)
5% in.
A105A Car-
Page 4
SR109
Professional Mixer
TABLE OF CONTENTS
Section
SPECIFICATIONS
DESCRIPTION OPERATING INSTRUCTIONS
Functional Identification General Operating Instructions 3 Mounting and Ventilation 4 Power Supply 5 Functional Circuit Description Inputchannels Monitor Mixer System Program Mix Amplifier 7 Link Jacks Program Output
VU Meter Circuit 7
Limiter Tone Oscillator Basic Operating Hints
SPECIAL OPERATING INSTRUCTIONS
High-Impedance Microphones Musical Instruments Tape Recording 9 Record Playback Tape Playback Additional Mixer Inputs Additional Mixer Inputs (Two SRlO9s) Redundant Mixer Set-up (Two Stereo Operation Remote Volume Control Telephone Line Surge Protection
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............
SRIO9s)
............
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Page
ii.
Section
iii
SERVICE INSTRUCTIONS
1 Mixer Service 14
Replacement Parts Fuse Replacement
3
Knob Replacement Service Access Lamp Replacement Board Removal
6
Limiter Internal Adjustment
6
Overload Indicator Check
6
VU Meter Removal VU Meter Calibration
7
Parts Removal
7
Transistor and Diode Removal Active Component Checking
8
Service Illustrations
8
Optional Accessories
8
REPLACEMENT PARTS LIST 19 NOTES TO CIRCUIT DIAGRAM
9
General 29
9
Troubleshooting 10 11 11 12 12 12 13 14
Ac Voltage Measurements
Dc Voltage Measurements
Resistance Measurements
CONDENSED OPERATING INSTRUCTIONS 35
ARCHITECTS' AND ENGINEERS' SPECIFICATIONS GUARANTEE 35 SHIPPING INSTRUCTIONS 35
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Page
14 14 14 14 14 15 16 16 16 16 17 17 17 18 18
29 29 30 30
. .
35
SR109
Professional Mixer
LlST OF ILLUSTRATIONS
Figure Page
1 SR109 Professional Mixer Front Panel 2 2 SR109 Professional Mixer Rear Panel 2
3 Overall Dimensions 4 Block Diagram 5 SR110 Monitor Mixer Applications 7
6
Tone Oscillator Applications 7 Preamplifier-Mixer Connections 8 Tape Recording 9 Record Playback
10 Tape Playback 11 Additional Mixer Inputs 12 Additional Inputs: Two
........................
.............................
................
............................
...........................
.............................
.....................
SRIO9s
...............
.........
..........
............
..............
9 10 10 11 11 12
Figure Page
13 Redundant Mixers 13 14 Stereo Tape Recording 13 15 Remote Volume Control
5
16 Printed Circuit Board and Parts Location 16
5
17 Opto-Isolator Test 18 Board
8
19 Board 2: Channel Equalizer 20 Board 3: Main Board 21 Board 9: Power Supply 22 Board 23 Lead Codes 24 SR109-2E Power Supply Circuit Diagram 30 25 SR109 Professional Mixer Circuit Diagram .3 2-33
1: Preamplifier
0: Program Mute
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13 17
24 25 26 27 27 29
......
..
Page 5
SR109
Professional
DESCRIPTION
Mixer
The Shure Model SR109 Professional Mixer is a solid­state, eight-channel microphone mixer-preamplifier that enables the operator to mix as many as eight microphones with individual control over input attenuation, volume and high- and low-frequency equalization. The Mixer has three outputs: a program output, an accessory output and a headphone output. In addition, channels
switch-selectable inputs for use with either low-impedance microphones or line level sources. A master volume con­trol regulates program output.
The program output has both a 600-ohm, balanced line
level output and a low-impedance, balanced, microphone output. The with separate volume control. A pair of link jacks facilitate connection to an additional mixer, or external equipment such as compressors, limiters or equalizers.
The
to one or more Shure The mixer designed to provide a separate stage monitor mix that follows the program mix levels. In addition, it may be used in multi-track recording as a submaster mix panel or mixdown panel.
The
put limiter with an in-out switch and an indicator lamp
that flashes when the limiter is operating. The front panel
also contains an overload indicator lamp that signals when
headphqne output is an &ohm balanced output
SR109 rear panel contains provisions for connection
SR110 Professional Monitor Mixers.
SR110 is a self-contained, eight-channel, line level
SR109 contains a peak-responding, adjustable out-
7
and 8 contain
the output is clipping in the non-limiting mode.
The Mixer contains a switch to adjust sensitivity to indicate program output level. A built-in 1 kHz tone oscillator facilitates synchronization of all meters in a system. space for pencilled notations.
The regulated power supply is designed to operate over a wide range of ac line voltages, permitting the use of extremely long ac extension cables without performance degradation. Accessory equipment drawing up to 500 watts may be connected to the rear-panel switched ac receptacle
The solid-state components in the Mixer are protected against damage as a possible result of open-circuit or short-circuit conditions on the inputs or outputs. All components are conservatively rated and are operated well within their respective ratings to assure long life and trouble-free performance.
The Mixer is supplied with rack-mounting screws and spare fuses.
The Mixer is Underwriters' Laboratories, Inc., listed,
and is listed by the Canadian Standards Association as
certified
The following are designed for use with the
fessional Mixer:
(SR109 only).
(SR109 only).
SR110 Professional Monitor Mixer
A1 05A Carrying Case
VU
meter and a meter sensitivity
A
front-panel trim strip provides
SR109 Professional
SR109 Pro-
Page 6
14
13
FIGURE 1. SR109 PROFESSIONAL MIXER FRONT PANEL
15 16 17 18
19
27
28
FIGURE
(SR109-2E
2.
SR109 PROFESSIONAL MIXER REAR PANEL
Only)
2
Page 7
SR109
Professional Mixer
FUNCTIONAL IDENTIFICATION (Refer to Figures 1 and 2,
Page 2.) NOTE: All front panel controls are numbered for ref-
erence only.
-
Individual Channel Volume Controls (Eight) trol volume and input clipping level of each channel separately. Channel 1 contains TONE
push-pull Switch - Pulling switch outward turns os­cillator on, and rotating control adjusts level of 1 kHz tone generated internally for set-up purposes.
Individual Channel tary Controls (Eight) -Adjust low-frequency signal equalization for each channel.
Individual Channel Rotary Controls (Eight) -Adjust high-frequency sig-
nal equalization for each channel. LIMITER Indicator Lamp
when LIMITER Switch (11) is turned on (IN).
OVERLOAD Indicator Lamp load condition (output clipping) when LIMITER Switch (11) is turned off (OUT).
True VU Meter
output. (Meets all current standards for VU Meters.) PHONES Rotary Control PHONES Jack (8). PHONES Output Jack- Provides for connection of
stereo or monophonic headphones for monitoring.
9. MASTER Volume Rotary control and POWER
-Adjusts level of totai program output, and applies ac power to power supply and SWITCHED AC Receptacle. THRESHOLD
Control -Sets threshold level of limiter function. LIMITER IN-OUT Slide Switch -Turns program out­put limiter on and off. Ac Grounded Line Cord to Mixer power supply 3AG-3/16A SLO-BLO Ac Fuse - Protects Mixer ac input line against overload
SWITCHED AC Grounded Receptacle to 500 watts of unfused switched ac power to acces­sory equipment
PROGRAM
verses phase (polarity) of
PHONE LEVEL program outputs with respect to
inputs. VU METER RANGE Slide Switch
(6) sensitivity for three ranges of program level indi­cation in ACCESSORY OUTPUT/AUX LEVEL 1 1-Pin Con­nector
Monitor Mixer. 15
dB ATTENUATORS/IN-OUT Slide Switches (Eight)
-
Provide choice of input signal attenuation for each
channel.
INPUTS/MICROPHONE LEVEL LOW IMPEDANCE Three-Pin Jacks (Eight) nection of low-impedance sources to channels 1
OUTPUTS/PHASE Slide Switch - Re-
dBm.
-
Provides output connection to Shure SR110
FREQuency EQualizer-LOW Ro-
FREQuency EQualization-Hlgh
-
lndicates limiting action
-
lndicates Mixer over-
-
lndicates volume level of program
-
Controls volume level to
ADJustment Screwdriver-Adjustable
-
Connects ac power source
(SR109 only).
(SR109 only).
-
Provides up
(SR109 only).
LINE LEVEL and MICRO-
-
Selects VU meter
-
Provide for balanced con-
Con-
OSCillator
switch
through 8 inputs, or line level sources to channels and 8.
MIC/LINE Slide Switches (Two) -Select low-impe­dance (MIC) or line level (LINE) input connections for channels LlNK OUTPUT Phone Jack - Provides output con­nection to external equipment or common mix bus to combine two or more Mixers.
LlNK INPUT Phone Jack - Provides input connection from external equipment (compressor, limiter, equal-
izer, etc.). PROGRAM
nector power amplifier. PROGRAM (Two) nection to power amplifier. PROGRAM Pin Connector phone-level program output. VOLTAGE SELECTOR Slide Switch -Selects oper­ating voltage range of 90 to 132 or 180 to 250 50/60 Hz (SR109-2E only). AC (MAINS) POWER 3-Pin Connector line cord to Mixer power supply 180-250V 0.1 Protects Mixer ac input line against overload (SR109-2E only).
GENERAL OPERATING INSTRUCTIONS
7
and 8.
OUTPUTS/LINE LEVEL Three-Pin Con-
-
Provides balanced output connection to
OUTPUTS/LINE LEVEL Phone Jacks
-
Provide balanced or unbalanced output con-
OUTPUTS/MICROPHONE LEVEL Three-
-
provides low-impedance micro-
-
Connects ac
(SR109-2E only).
AT/90-132V 0.2AT SLO-BLO Ac Fuse
Vac,
WARNING
Voltages in this equipment are Make all input and output connections before ac power is connected. Refer servicing to qualified
service personnel.
1.
Using hardware provided, install Mixer securely in standard 19 in. (483 mm) rack or optional rying Case prior to making electrical connections.
2.
Set front-panel switches to off or OUT and all controls to
0.
Set rear-panel PHASE Switch (15) to
3. Connect desired PROGRAM OUTPUT/LINE LEVEL Connector (23, 24) to
ing cable. (NOTE: Shure
supplied with audio connecting cables.) If Mixer out-
put is to be fed to another mixer or tape recorder microphone input, use PROGRAM PHONE LEVEL Connector (25). If desired, connect monophonic or stereo headphones to front-panel PHONES Jack (8). Connect speakers to power ampli-
fier.
4.
Connect one or more low-impedance microphones to rear-panel PEDANCE Connectors (19). Any high-quality dynamic,
INPUTS/MICROPHONE LEVEL LOW IM-
power amplifier input connect-
hazardous to life.
A105A Car-
OO.
SR105 Power Amplifiers are
OUTPUT/MICRO-
7
-
Page 8
ribbon or condenser low-impedance microphone may be used. Connect line level sources to channel 7 or 8 connectors only. If line level inputs are used, set
corresponding
If external signal-processing equipment such as an
5.
MICILINE Switch (20) to LINE.
equalizer, compressor or limiter is to be used, con-
nect Mixer
equipment input and external equipment output. (See 7, for detailed information.) If a Shure
LlNK OUTPUT Connector (21) to external
LlNK INPUT Connector (22) to
Link
Jacks,
Page
SR110
Monitor Mixer is to be used with the SR109, connect multi-pin plug of Connector (17) of
SR110 to ACCESSORY OUTPUT
SR109.
6. SR109: Connect ac line cord (12) to grounded 90- to 132-volt, 50160 Hz ac source. Line cord is a
2.4m
(8 ft), 3-conductor cord with 3-pin grounding plug.
If extension cords are required, use high-quality, rubber-jacketed cable with 18 gauge (0.8 mm2) or heavier wire.
SR109-2E: Obtain suitable &pin male ac connector
and attach to line cord: brown lead to "hot" or "live"
terminal, blue lead to neutral terminal, and
green1 yellow lead to ground or earth terminal. (Connector should be installed by qualified service personnel.) Select proper operating voltage (90-132V or
180­250V) using VOLTAGE SELECTOR Switch (26). Note that switch positions are marked 115 and 220 volts. Make certain proper fuse is installed in fuseholder (28):
O.1AT with switch set to 220, or 0.2AT with
switch set to 115. Insert female end of line cord into
chassis power connector (27) and connect male plug
to 3-wire grounded ac power receptacle providing
proper operating voltage.
7. Turn on front-panel MASTER Volume
ControllPOW-
ER Switch (9) and allow one to two minutes warmup time. This warmup time allows the supply voltages to stabilize and capacitors to charge to provide opti-
mum performance. Set 15 dB ATTENUATOR Switch
(18) initially to OUT for normal PA use, to IN for
"hard" rock music. For nels 7 and 8), set
LINE INPUT sources (chan-
MICILINE switch (20) to LINE.
8. Set Master Volume Control (9) to 6. Set VU METER RANGE Switch (16) to (when using a Western Electric
0 for PA or telephone line use
308 Voice Coupler), +4 for recording, or +8 for broadcast use. Have someone sing or talk into microphone and raise chan­nel Volume Control (1) to achieve desired sound level. If meter reads low at proper sound level, reduce power amplifier volume level and increase channel volume level. For single microphone set-up, if meter
indicates excessively high level ("pinning" or "peg­ging" needle), decrease MASTER Volume Control to obtain good meter reading and increase power ampli­fier volume level or input sensitivity to obtain proper sound level. In multiple microphone set-up, it may be necessary to decrease MASTER Volume Control in order to maintain channel Volume Control setting. Ideally, set the channel Volume Controls as high as possible (consistent with an adequate mixing range), and increase the MASTER Volume Control to obtain a
0 VU Meter reading. Then increase the power ampli­fier level control to the desired level. Using the 15 dB ATTENUATORS (18) may aid in maintaining this set­ting if the channel Volume Control is consistently set low.
9. Set
HI and LO FREQ EQ Controls use. Vertical position response. Clockwise
(0) indicates "flat" frequency
(+)
(3,
2) for channel in
settings increase high­frequency (treble) or low-frequency (bass) level and counterclockwise
(-)
settings decrease the high- or
low-frequency level.
10. With LIMITER Switch (11) in OUT position, OVER­LOAD Indicator Lamp (5) will flash when Mixer out­put clipping level is exceeded. If limiting is desired,
adjust limiter as follows: Operate Mixer with program
material and adjust the channel and MASTER Volume
Controls (1, 9) for desired sound level. With small screwdriver, turn THRESHOLD ADJ Control (10) full counterclockwise. Set LIMITER
INIOUT Switch to
IN. Slowly increase (clockwise) THRESHOLD ADJ
Control until LIMITER Lamp
(4)
flashes intermittently,
indicating limiting action on program peaks. A con-
tinuous glow indicates an undesirable excess of lim-
iting: MASTER
andlor channel Volume Controls should be reduced. Increasing channel or MASTER Volume Controls will not increase mixer output above the level just set. Should higher or lower maximum output level be desired, increase or decrease THRESHOLD ADJustment. (An alternate set-up pro-
cedure uses the TONE
OSCillator to produce a maxi­mum desired VU level. The THRESHOLD ADJustment is slowly increased (clockwise) until the VU Meter reading just set is reduced by 1 dB. Note that with this set-up, the program material level displayed on the VU Meter will be lower because of the difference between peak and average levels. However, limiting action will take place at the same peak level. This effect will be more evident on speech than on music.)
11. Monitor output is available at front-panel PHONES Jack (8). Adjust PHONES Control (7) for comfortable
listening level.
12. NOTE: During temporary shutdown (break, intermis­sion), do not turn off Mixer power. It is designed to operate continuously, and optimum performance is
maintained after internal voltages are allowed to sta­bilize. Also, do not turn down all microphones. Leave the master or announcer's microphone on so that if
the Mixer is left unattended, announcements may be
made, and the operator will be alerted that the next performance is about
to begin.
MOUNTING AND VENTILATION
The Shure
SR109 Professional Mixer may be operated
in a standard 19 in. (483 mm) audio equipment rack (see
Figure 3, Page
5),
or in a Shure A105A Carrying Case.
Four rack-mounting screws are provided with the Mixer.
The Shure rack-mounting space. When the case, an additional rack-mounted unit such as the
A105A Carrying Case has a 7 in. (178 mm)
SR109 is mounted in this
SR110 Monitor Mixer may be mounted in the remaining 1% in. (44.4 mm) space.
In rack-mounted installations, consider rear-panel ac-
cess before installation is made. Although most installa-
tions will not require frequent access, it should be re-
membered that input and output changes, and some switch movements, will necessitate rear-panel access.
Page 9
FIGURE
3.
OVERALL DIMENSIONS
POWER
SUPPLY
SR109: The Mixer regulated power supply is designed
to operate from 90 to 132 volts ac,
50/60
Hz
without ad­justments, allowing the Mixer to meet all specifications over this wide range of ac input voltages.
A
three-con­ductor, grounded line cord (12) supplies ac power to the Mixer through the front-panel POWER Switch (9). The Mixer consumes 20 watts maximum (0.2 amperes) and the
ac line input is protected by a
(13) and a wired-in
3/10-ampere slow-blow fuse in series.
3/16-ampere slow-blow fuse
'(TYPICAL
-50 DB -1100 XFMR
ATTENUATOR ATTENUATOR
NOTE I
[-
m]
600A
RESISTOR
Y
OF
CHXNELS
23DB CHANNEL
200x~:HGH VOLUME CHANNEL
1-8)
m
0
v
0
PHONES
LEVEL
/
FIGURE
u
METER
1'
4.
SR109 BLOCK DIAGRAM
NOTES I MIC-LINE SWITCHES ON CHANNELS
2 TONE GENERATOR ON CHANNEL I ONLY
-
-
7
AND 8 ONLY
Page 10
These fuses should not be replaced with
CAUTION
any other size or type of fuse.
Accessory equipment may be connected to the panel SWITCHED AC Receptacle (14). The accessory equipment may consume up to 500 watts maximum, which provides for use with high-power amplifiers such as the
SR105. Note that the receptacle is switched but not
Shure fused; all accessory equipment used with the Mixer should contain its own fuse.
SR109-2E: The SR109-2E regulated power supply is designed to operate from either 90 to 132 volts ac or 180 to 250 volts ac, VOLTAGE SELECTOR Switch (26). A three-conductor, grounded line cord supplies ac power to the Mixer through the front-panel POWER ON-OFF Switch (9). The
SR109-2E line cord does not have a connector on the
power source end of the cord. Obtain a suitable male ac connector and install it on the line cord: brown to "hot" or "live" terminal, blue lear to neutral terminal,
green/yellow lead to ground or earth terminal. (Con-
and nector should be installed by qualified service personnel.) The ac line is protected by a 0.1-ampere Slo-Blo fuse (for 180- to 250-volt operation) or a 0.2-ampere Slo-Blo fuse (for 90- to 132-volt operation. A wired-in fuse also protects the ac line.
FUNCTIONAL CIRCUIT DESCRIPTION (See Figure 4, Page 5)
Each three-pin professional audio input MICROPHONE LEVEL Connector (19) feeds its own low-impedance bal-
anced lnput Transformer, which provides gain of 23 dB.
Channels 7 and 8 also contain
which switch in a 50 dB bridging line-to-microphone
level Attenuator to accept line-level inputs. The lnput Transformers (and, on channels 7 and 8, the Switch) are fed to 15 dB ATTENUATOR Switches (18) and then to the Preamplifier, which provides gain. The amount of voltage gain provided by the Pre­amplifier (7 to 42 dB) is controlled by the Channel Volume Control as gain is reduced. The Preamplifier circuits contain the individual Channel Volume Controls and feed the indi­vidual Channel Equalizer (HI and LO FREQ EQ) Controls (3,2) which decrease the signal approximately 3 dB when set to the 0, or "flat," setting.
fier and the ACCESSORY OUTPUT Connector (17) for interconnection with Mix Amplifier feeds through a 560-ohm resistor to the LlNK jacks (21, 22). When accessory equipment is not connected to the the program signal is fed to the MASTER Volume Control (9) and back to the ACCESSORY OUTPUT Connector.
a The attenuated signal feeds a limiter, which is connected to a Lamp Driver (for driving the LIMITER and OVERLOAD lamps) and a Limiter THRESHOLD ADJ Control (10) for setting the threshold of Limiter operation. Note that when the LIMITER Switch (11) is turned off (OUT), the LIMITER Lamp (4) will not light, but the OVERLOAD Lamp flash whenever the output clipping level is exceeded. The Limiter Attenuator also feeds a Amplifier, also controlled by the MASTER Volume Control.
(I), providing an increase in input clipping level
The Equalizer outputs are fed to the Program Mix Ampli-
The output of the MASTER Volume Control, after feeding
0 dB gain Amplifier, is sent to a Limiter Attenuator circuit.
50/60 Hz, as selected by the rear-panel
3/10-ampere
MIC/LINE Switches (20)
+7 to +42 dB
SR110 Monitor Mixers. The Program
LlNK jacks, the jacks are bypassed and
+7 to +35 dB output
rear-
three-'pin
MIC/LINE
(5)
will
The signal then goes through a
and into the Program Output Transformer. The Trans-
former feeds three
24) and a MIC LEVEL Output Connector 50 dB below line level. The
fier also feeds the VU METER RANGE Switch
goes to a +22 dB Meter Amplifier and then to the VU
(6), and a PHONES Level Control (7), Headphones
Meter
Transformer and PHONES Output Jack (8).
The Mixer also contains a in set-up and check-out. The Generator is activated and controlled by the channel 1 Volume Switch
and their uses is provided in the following paragraphs of this section.
INPUT CHANNELS LEVEL lnput Connectors (19) are provided on the rear
panel of the Mixer. The Mixer is designed to operate with high-quality, low-impedance dynamic, ribbon or condenser microphones. Each low impedance microphone input connected to a low-impedance, balanced-input transformer through a 15 dB input ATTENUATOR (18). Two Slide Switches (20) are provided for channels 7 and 8. These switches allow the user to select between either low-impedance MICROPHONE or additional line level inputs are required, Shure lnput Adapters may be used in each microphone level input.
vides input attenuations of the user to compensate for the differences in levels due to
different sources, such as close talking or distant micro­phone placement, and to compensate for high output levels from condenser microphones.
section, in a feedback circuit, sets the gain of the pre­amplifier; the second section is a preamplifier output tenuator. This circuit configuration increases the pre­amplifier input clipping level as the Volume Control is reduced to lower settings. Ideally, the control should op­erate in the middle range, between 4 and be accomplished by proper 15 dB ATTENUATOR Switch
(18) setting.
equalizer circuit. Individual HI and LO FREQ EQ controls
(3,2) allow the user to shape the sound of each input chan­nel without affecting the other channels of the Mixer. The HI FREQ controls provide up to 13 dB of boost or cut at 10 kHz with a 1 kHz hinge point. The LO FREQ controls pro­vide up to 13 dB of boost or cut at 100 Hz with a 1 kHz
bin-ge
cate boost, and minus (-) markings denote cut. A ting provides a normal or "flat" frequency response.
PUT/AUX LEVEL Connector (17) and the Program Mix Amplifier.
MONITOR MIXER SYSTEM nector (17) of the
one or more Shure The output of each individual channel after all channel controls (volume, equalization and attenuation) appears
(I), and the Control output is fed to the Preamplifier.
A detailed description of the Mixer circuits and controls
Eight professional, three-pin, audio MICROPHONE
The 15 dB ATTENUATOR (18) two-position switch pro-
The Channel Volume Control
The output of the Channel Volume Control (1) feeds the
point. Control settings with plus
The output of the equalizer feeds the ACCESSORY
The rear-panel ACCESSORY
LlNE LEVEL Output Connectors (23,
SR109 provides for interconnection to
SRl10 Professional Monitor Mixers.
0'-180' PHASE Switch (15),
(25), which is at
+7 to +35 dB output Ampli-
(16), which
1 kHz Tone Generator for use
Control/TONE OSC
is
MIC/LIINE
LlNE LEVEL inputs. If
0 or 15 dB. This switch allows
(1) is a dual control: one
(+)
OUTPUT/AUX LEVEL Con-
A15LA Line
9.
This can often
markings indi-
at-
0 set-
OUT-
Page 11
on this connector as do the LlNK INPUT total mix signal and the power supply connections. The
SR110 is a self­contained, eight-channel, line level mixer designed for use with the
SR109 or similar equipment. The SR110 can provide a separate stage monitor "mix" that follows the program "mix" levels coming from the eight channels of
SR109. In addition, it may be used in multi-track re-
the cording as a submaster mix panel or as a "mixdown" panel.
SR110 provides eight high-impedance, unbalanced,
The line level inputs to its mixing circuity, one high-impedance, unbalanced, line level input to its Output Selector Switch for monitoring the program mix, and one line level,
600­ohm, balanced output. Individual channel and master vol­ume controls are provided, as is a switch to choose be­tween monitoring the channels in use (Mixed Inputs) and the total program mix (Program Input). The Mixed Inputs position takes the signal from each channel frequency equalization circuit, and the Program
Input position obtains
the mixed signal at the LlNK INPUT Jack (22).
SR110 has parallel accessory input/output male and
The
female connectors. These connectors permit the connec-
tion of addition tandem or "stacked"
SRllOs. A typical
application is shown in Figure 5, Page 7. PROGRAM MIX AMPLIFIER
The program mix amplifier is an active mixing ampli­fier in which gain remains constant independent of the in­dividual channel volume control settings. The output of the program mix amplifier is connected through a 560-ohm mixing resistor to the LlNK Jacks (21, 22).
SR1w LINE MIXER LEVEL
ACC
OUT
SRl I0
MONITOR
MIXER
SRllO
MONITOR
MlXER
SRllO
MONITOR
MIXER
FIGURE
POWER
AMPLIFIER
POWER
AMPLIFIER
STEREO
TAPE
RECORDER
5.
SRllO MONITOR MlXER APPLICATIONS
PA
SPEAKERS
STAGE
MONITOR
SPEAKER
LlNK JACKS
The LlNK Jacks
(21,22) on the rear panel of the Mixer enable the user to interconnect more Mixers for additional inputs or add external equipment, such as equalizers, compressors, or limiters. When connecting two or more SR109 Professional Mixers together to provide many chan­nel inputs, connect the LlNK OUTPUT Jacks (21) of all the units together. It should be noted that the LlNK OUT­PUT Jack is actually a two-way jack; the impedance at this point is actually 600 ohms, and any number of units may be tied together at this point. The LlNK INPUT Jack
(22) is an input-only jack and has switching contacts that
disconnect the LlNK OUTPUT signal from the MASTER Vol-
ume Control (9). Note that the
SR109 and the Shure SR101
Audio Console may be interconnected in the same manner.
If an equalizer, limiter or compressor is connected to the Mixer, the LlNK OUTPUT Jack (21) is connected to the input of the external unit and the output of the external unit is connected to the LlNK INPUT Jack (22).
The signals at the LlNK Jacks are typically at a level 10 dB below line level. These jacks will accommodate sig­nal levels in the range between LlNK INPUT impedance is greater than 20
30 to +10 dBm. The
kilohms and
may be considered a bridging impedance. The output of
the LlNK Jacks feeds the MASTER Volume Control (9)
which is a two-section control similar to those used in the individual channels. The LlNK INPUT Jack is connected to the ACCESSORY
OUTPUT/AUX LEVEL Connector (17).
PROGRAM OUTPUT
The signal from the LlNK Jacks (22, 21) drives the pro­gram output amplifier. The gain of this amplifier is con­trolled by one-half of the MASTER Volume Control (9) (the other half is an input attenuator for the output amplifier). In addition to the limiter circuitry, the program output amplifier also contains the front-panel OVERLOAD Indi­cator Lamp (5). This indicator will flash when the output clipping level is exceeded, and only when the LIMITER Switch (11) is in the OUT position. The output of the pro­gram amplifier is sent to the PHASE Switch (15) mounted on the rear panel of the Mixer. This switch allows the user to change the phase of the program output, which may be helpful in eliminating or reducing low-frequency acoustic feedback. Generally, this switch is adjusted to the position which either gives the most gain before feedback or, if both positions give the same gain before feedback, use the po­sition that produces the highest pitch feedback. The pro­gram signal, after leaving the PHASE Switch, is routed to the output transformer which provides both LlNE LEVEL and MICROPHONE LEVEL outputs. The LlNE LEVEL out­put is connected to one professional three-pin, male, audio output connector (23) and two three-circuit phone jacks (24). The MICROPHONE LEVEL output is a low-impedance, balanced output, 50 dB below the LlNE LEVEL output, and is connected to a professional three-pin, male, audio out­put connector (25).
Note that all of the program outputs are balanced with respect to ground. If a two-circuit type phone plug is used to connect the mixer line level output to an amplifier or tape recorder, the line outputs will automatically become unbalanced. If the three-pin unbalanced output is used and a phone jack output is also to be used, obtain a stereo phone plug and
corrnect the tip and ring of the plug only.
(The sleeve is a shield and would cause a ground loop.)
If it becomes necessary to use the MICROPHONE LEVEL Output Connector (25) to feed a high-impedance micro­phone input, use a line matching transformer such as one of the Shure A95 Series at the high-impedance microphone input.
The output of the program output amplifier is also fed
to the VU Meter (6) circuit. VU METER CIRCUIT
To allow a wide range of signals to be handled by the
VU Meter
(6), a VU Meter amplifier is provided. The output of the program amplifier is fed to the VU METER RANGE Switch (16) which in turn feeds the VU Meter amplifier and the Meter. The VU METER RANGE Switch provides a
Page 12
choice of 0, +4 or The
0 setting is usually used for PA applications, +4 is the
standard for recording use, and
+8
dBm output levels for the VU Meter.
+8 is preferred for use
by broadcasters. The calibration of the VU METER RANGE
0
Switch is internally adjusted at the factory for a 600-ohm load on the program output in the
VU across
+4 dBm switch position. The VU Meter amplifier provides the proper impedance and signal level for correct VU Meter ballistics and calibration. This amplifier also isolates the Meter from the program output and eliminates the dis­tortion normally caused by the nonlinearities of VU meters.
LIMITER
The program output amplifier also contains a
peak­responding, rapid-acting, limiter circuit. When the LIM­ITER Switch (11) is turned on (IN), and the THRESHOLD
ADJ Control (10) is properly adjusted, the LIMITER In­dicator Lamp (4) will flash whenever the limit threshold is exceeded and the limiter is functioning. The dynamic range
of the limiter is approximately 30 dB.
Set the limiter THRESHOLD ADJ Control (10) as fol-
lows. Operate the Mixer with program material, and adjust
the individual channel and MASTER Volume Controls (1, 9) for the desired level. With a small screwdriver, turn
the THRESHOLD ADJ Control full counterclockwise. Set the LIMITER IN-OUT Switch (11) to IN. Slowly increase (turn clockwise) the THRESHOLD ADJ Control until the
LIMITER Indicator Lamp (4) flashes, indicating limiting ac-
tion on program peaks. Note that increasing the channel
or MASTER Volume Controls will not increase the mixed
output above the level just set. Should a higher or lower maximum output level be desired, increase or decrease the THRESHOLD ADJ Control.
An alternate method of limiter threshold adjustment is
to turn on the TONE
Oscillator (1) to produce a maximum reference level on the VU Meter (6). Adjust the THRESH­OLD ADJ Control (10) clockwise until the VU Meter reading
just set is reduced by 1 dB. The program material dis-
played on the VU Meter will be lower because of the difference between peak and average levels, but limiting action will take place at the same peak level. This effect
will be more evident on speech than music.
TONE OSCILLATOR
The Mixer contains a built-in 1 kHz tone oscillator for
set-up and check-out purposes. The TONE OSC Control
and On-Off Switch
(1)
injects the 1 kHz tone into the chan­nel 1 preamplifier. The tone is processed through the pro­gram channel in the same manner as microphone or line input signals.
The tone oscillator may be used as follows: With the VU METER RANGE Switch (16) set to MASTER Volume Control
until a
0
VU reading is obtained on the VU Meter. A tone
(9)
and TONE OSC Control (1)
+4,
increase the
reference level has now been established. The Mixer LlNE
LEVEL Output (23,
24)
is now
4-4
dBm (1.23 volts across a 600-ohm load) and the MICROPHONE LEVEL Output (25) is approximately 4 millivolts. These reference signals may be used to set up power amplifiers, tape recorders, or other equipment connected to these outputs (Figure
6A, Page
8). By adjusting the input level (or volume) controls on
the associated equipment, all meters in the audio system
can be made to "track." This allows the Mixer operator to observe only the Mixer VU Meter.
The tone oscillator may also be used to provide a check of cables and equipment connected to the link output. With the
LlNK OUTPUT Jack (21) connected to the input
@
MIC
LINE LINE
TAPE
RECORDER
GATED
COMPRESSOR
MIXER
6B,
Page 8). Set
(23)
(15)
-
SLO-BLO
has not
is not be-
@
SR 109 MIXER
POWER AMPL
SR
109
MIXER
FIGURE
6.
TONE OSCILLATOR APPLICATIONS
POWER
AMPLIFIER
-
MIC
AUX LEVEL
INPUT JACK
of external equipment, such as a Shure SE30 Gated Com­pressor/Mixer which in turn feeds a broadcast line, dis­connect the Mixer output, either at the back of the Mixer,
power amplifier or speakers (Figure
the MASTER Volume Control
(9)
to 6 or the normal op­erating position, and increase the TONE OSC Control (1) for a
0 VU reading on the VU Meter (6). Set the MASTER
Volume Control to
0.
Under this set-up condition, the ex­ternal equipment may now be calibrated or checked out without affecting the Mixer output. After calibrating the ex­ternal equipment, turn off the tone oscillator, and return the MASTER to the previous setting. Reconnect the power amplifier or speakers.
BASIC OPERATING HINTS
Should any difficulty be encountered in Mixer operation, the problem may often be traced to some simple source such as an error in interconnection. The following is of­fered as a basic guide to problems of this sort.
Symptom: Mixer is "dead" (no output, VU METER lamps
out)
Check: 1. Check that ac power source is "live" and
that Mixer is plugged in.
2. Check that POWER OFF Switch (9) is on.
3. Check to see that rear-panel Fuse (13, 28) is good.
Symptom:
Mixer is "dead" (no output, VU Meter lamps lit)
Check: 1. Check that cable from PROGRAM OUT
PUT/LINE LEVEL Connector accidentally been connected to PRO­GRAM
OUTPUT/MICROPHONE LEVEL
Connector (25).
2. Check that PHASE Switch tween positions.
3. If external equipment is connected to LlNK Jacks (21, 22), disconnect external equipment to determine whether fault is in external equipment.
Symptom: One channel is "dead" (other channels oper-
ating properly)
Check:
1.
Check for defective input cable or source. Check that
2. nels
7
MIC/LINE Switch (20) (chan-
and 8 only) is not between positions
or in the wrong position.
Page 13
SR109
Professional Mixer
SPECIAL OPERATING INSTRUCTIONS
The previous section described normal interconnection nel 7 or 8 jack with MIC/LINE Switch in LlNE position). If and operation of the provides information on special set-ups to more fully uti- 1 and the hot conductor to pin 3 of the input jack. As an lize the capabilities of the Mixer.
HIGH-IMPEDANCE MICROPHONES
High-impedance phones (crystal
mended) MICROPHONE LEVEL Input Jacks (191, providing a line matching transformer (Shure A95 Series) is used. NOTE:
The
sate microphones.
The high-impedance cable should be limited to 6m (20 ft). of high-impedance, single-conductor, shielded cable (Bel-
den #8401, #8410, or #8411) between the microphone Output the speaker jack; damage and line matching transformer, and add as much low-im- may may be
pedance, two-conductor,
or
Mixer
frequency
and noise.
MUSICAL INSTRUMENTS
Musical tical-electrical, or electrified, may be amplified through the Mixer. For acoustical instruments, place a microphone close to the instrument strings, sounding board, or mouth. Adjust equalization and volume controls as necessary.
For acoustical-electrified instruments such as classic or folk guitars with pickups and preamplifier outputs, or pianos with pickups and preamplifier outputs, either place the microphone as described above, or connect the pickup to a line matching transformer as described under
High-Impedance Microphones (Page 9). Adjust the 15 dB ATTENUATOR Switch (8) for the channel the desired sound level with the channel Volume
(1) set at about mid-scale.
To use a preamplifier auxiliary output (instrument or impedance auxiliary tape recorder input, connect a cable
tape recorder preamplifier, or hi-fi amplifier tape monitor from one LlNE LEVEL Jack to the tape recorder input (see
output jack, or headphone jack; not the speaker jacks- Figure 8, Page 10). If the LlNE LEVEL Output is being amplifier damage may result) with the Mixer, connect the used and a two-circuit phone jack is used to connect the preamplifier auxiliary output to a LlNE LEVEL input (chan- Mixer to the tape recorder, this will unbalance the LlNE
l5
dB
the
If a long
#8422)
input
can
ATTENUAToR Switch
very high Output produced
cable
as
jack.
signal loss and reduce the possibility of hum
instr~ments, aco~stical (n0n-electrified), acous-
SR109 Professional Mixer; this section the source is unbalanced, connect the cable shield to pin
alternate connection, connect the preamplifier auxiliary output through up to 3m (10 ft) of cable to the high-impe-
dynamic, ribbon or condenser micro-
Or
ceramic
be
used
with
One
length
necessary between
These
is
required,
shielded
precautions
may
are recorn-
the
1°w-im~edance
be
used
use
up
to
cable
(Belden
the
transformer
will
help
avoid
in use to provide nection, the operator should decide whether he wants the
'Ompen-
3m
#8412
high-
Control tape level to follow the MASTER Control and LIMITER.
dance side of a line matching transformer (Shure A95 series)
impedance side of the transformer through a low-imped-
ante
MICROPHONE LEVEL Input Jack (19). Adjust Mixer
equalization controls
15 dB ATTENUATOR Switch (18) for the channel in use to provide the desired sound level with the channel Volume Control (1) set at about mid-scale.
ft)
a
scribed above. It is important to note that the tonal quality of fully electrified instruments is primarily formed by the
and
instrument amplifier and speaker; an external microphone
picking up
provide a more desirable sound than that obtained by di-
rect connections.
microphones also apply to most musical instruments (see High-Impedance Microphones, Page 9).
TAPE RECORDING
from either the LINE LEVEL Output (23,241, MICROPHONE
LEVEL Output (25) or LINK OUTPUT (21) Jacks. The Mixer
Program Outputs are after the MASTER Volume Control (9) and LIMITER Switch (11); the LINK OUTPUT Jack is
before these features. In planning a tape recorder con-
as
shown
microphone cable (up to 300m-1000 ft) to a Mixer
Fully electrified instruments may also be amplified using
the
The cable length restrictions applying to high-impedance
The Mixer output may be recorded on a tape recorder
To use a
LINE LEVEL Output Jack (23,24) feeding a high-
in
in
front of
fed
instrument
~i~~~~
for
7,
Page
9.
connect the
optimum sound. ~dj~~t the Mixer
the
instrument speaker,
to an jack as de-
Output may very
Or
the
low-
in-
r
AUX OR HEADPHONE OUT
PREAMPLIFIER
3
m
(10')
MAX.-
HIGH IMPEDANCE
FIGURE
p=-UP
>
A95 LINE
MATCHING
TRANSFORMER
LOW IMPEDANCE
MICROPHONE
7.
PREAMPLIFIER-MIXER CONNECTIONS
LOW IMPEDANCE
CABLE
TO
300
m
(1000')
1
MIC LEVEL
INPUT
SR
109
MIXER
1
9
Page 14
LEVEL Output (refer to Program Output, Page
7).
If the MICROPHONE LEVEL Output Jack (25) is to be
used, connect a cable from it to the tape recorder
low-
impedance microphone input. If the microphone input on
the tape recorder is designed to be used with
high-imped-
ance microphones (greater than 1000 ohms), insert a
line matching transformer (Shure A95 Series with proper connectors) between the MICROPHONE LEVEL Output
Jack and the tape recorder input (refer to Program Output, Page
7).
To use the LlNK OUTPUT Jack (21), use a two-circuit phone plug on the cable to the tape recorder auxiliary or line input. The input impedance of the tape recorder should
be 600 ohms minimum.
The output impedance of the
LlNK OUTPUT Jack (21) is low; this provides for unlimited cable length between the Mixer output and tape recorder input. Low-capacitance, single-conductor, shielded cable (Belden
#8401, #8410, or #8411) is recommended to reduce the possibility of hum and noise pickup.
For operation with a stereo tape recorder, refer to Stereo
Operation, Page
12.
RECORD PLAYBACK
To play records through the Mixer using a turntable or record changer with a stereo magnetic cartridge and no preamplifier, the most expedient method is to join the left and right channel leads from the turntable in a
"Y"
adapter and connect the joined output through an A95 Series Line Matching Transformer to a MICROPHONE LEVEL lnput Connector (19) on the Mixer (see Figure
9A, Page 10). Note that the total lead length between the turntable and the A95 should not exceed
1.5m (5 ft). To approximate the
RlAA equalization curve, set the Mixer FREQ EQ-LO Con-
trol (2) to +4, the FREQ EQ-HI Control 15
dB
ATTENUATOR Switch (18) to 0 for the channel being
(3)
to -6, and the
used. Adjust the channel Volume Control (1) as necessary.
LOW
IMPEDANCE
I
1
I
I
MIC
BALANCED
LEVEL
OUTPUT
FIGURE
LINE
8.
1
I
TAPE
RECORDING
A better method of performing this interconnection in-
volves the use of a phono preamplifier such as the Shure
M64 Stereo Preamplifier (see Figure
96, Page 10). In this set-up, RlAA equalization will be achieved at the pre­amplifier, before the signal enters the Mixer. In this manner, the Mixer equalization controls may be used to optimize the room sound, rather than compensating for the input signal. The joined turntable leads enter the channel 1 input of the preamplifier, and the output is taken from the chan­nel 1 low level output and fed to a MICROPHONE LEVEL lnput Jack (19) of the Mixer. Set the Mixer 15 dB
ATTENU-
ATOR Switch (18) to 0 with this set-up.
Note also that this set-up removes the cable restriction
between turntable and Mixer described above; although
I
@
@
TURNTABLE
r
TURNTABLE
A95
MIC
INPUT
SR
109
MIXER
1.5
m
(5')
MAX.-=
4f
CHAN.1
INPUT
ONLY
FIGURE
ONE
M64
PREAMPLIFIER
CHANNEL
9.
RECORD
STEREO
IS
p-UP
'
CHAN.
LOW LEVEL
i
OUTPUT
USED
FOR
PLAYBACK
FREQ. EQ-L0:+4
(
FREQ.
I
THIS
APPLICATION.
EP-HI:
TO
300
-6
rn
(1000')
)
1
MIC
SRlOS
MIXER
INPUT
Page 15
a maximum of 1.5m (5 ft) between turntable and preampli­fier is mandatory, the cable length between the preampli­fier and Mixer is virtually unlimited.
TAPE PLAYBACK
To play tape-recorded material through the Mixer, con-
a
nect output to the channel 7 or 8 For unbalanced tape recorder outputs, connect a conductor, shielded cable as shown in Figure 10, Page 11. Connect the tape recorder output cable shield to pin and the "hot" conductor to pin lnput Jack.
or 8 (whichever is being used) to LINE. Set the 15 dB
TENUATOR Switch (18) to 0, and the channel Volume
Control (1) as required.
cable from the tape recorder auxiliary or line level
LlNE LEVEL lnput Jack (19).
3
of the SR109 LlNE LEVEL
Set the rear-panel
TAPE RECORDER
AUX OUTPUT
MIC/LINE Switch (20) on channel 7
c-------
-------
\
--
I
SR109 MlXER
(CHANNEL 7 OR
single-
AT-
8)
-
ure 11B, Page 11). Set the SR109 15 dB ATTENUATOR Switch (18) to this set-up with other mixers, essentially the same pro­cedure is followed. The Shure M67 mixer, for instance, may be connected to the mixer line out connector (binding posts) or headphone out­put (phone jack) (Figure 11 C, Page 11).
If a mixer is to be used with the
to maintain as many
can be connected to the
IlD, Page 11). However, this requires sacrificing the
1
channel equalization functions for the sources entering through the mixer. The only
erating on the mixer sources in this set-up are the MASTER Volume Control
PHASE Switch (15). In addition, any mixer used in this set­up requires a output to provide an attenuator bridging connection; the
resulting signal level will be down -10 dB (see Figure Page 11). The M67 Mixer headphone jack has suitable built-in resistors and may be connected directly to the SR109 LlNK OUTPUT Jack. Only mixers with 600-ohm line outputs may be used in the configuration. Note that the
M68FC mixer cannot be used this way.
Shure
mixer-to-link out jack connection can also be used
The
with several
0 and the MIC/LINE switch to LINE. To use
SR109 LlNE INPUT Jack through the
SR109 but it is desirable
SR109 channels as possible, the mixer
LlNK OUTPUT Jack (21) (Figure
SR109 control functions op-
(9), LIMITER Switch (11) and rear-panel
2.2-kilohm resistor in series with the mixer
mjxers. Each mixer output must contain its
11E,
FIGURE
ADDITIONAL MlXER INPUTS
Additional microphone or other source inputs may be obtained using a high gain, low noise, microphone mixer such as the Shure PHONE LEVEL provide a total of 11 inputs (see Figure (Note that adding a mixer at an channel to a submaster control; the total number of inputs
will thus be the mixer total plus the
minus 1 for the submaster.)
A common practice when adding a mixer in this manner
is to connect similar-use microphones (for instance, all
drum, string or horn microphones) to a single mixer which
is fed into the
ume Control (1) then controls an entire section, facilitating adjustment of that section during a performance. With this set-up, set the channel 15 dB ATTENUATOR Switch (18)
0 and adjust the mixer channel volume controls in the
to mid-to-high range. Adjust the mixer master volume control as required to keep the the desirable middle range.
M68FC mixer has a switch-selectable low- or high-
The impedance microphone output. When using an M68FC­type mixer into an SR109 MICROPHONE LEVEL lnput Jack (19), set the mixer MIC OUT switch to low impedance, and make necessary adjustments as described above. It is sometimes desirable to use the auxiliary output from the mixer into the (Refer to this set-up.)
To use this set-up with an between the mixer auxiliary output (phono pin jack) and
SR109 LINE INPUT Jack (19) on channel 7 (or 8) (Fig-
the
lnput Jack (19), the M68FC and SR109 will
SR109. The SR109 individual channel Vol-
SRl09 channel 7 (or 8) LlNE INPUT (19).
Tape
Playback,
10.
TAPE PLAYBACK
M68FC. When connected to a MICRO-
11A, Page 11).
lnput Jack converts that
SR109 total
SR109 channel volume control in
Page 11, for a description of
M68FC mixer, connect a cable
---8
-
@
0
0
LOW IMPEDANCE
MIC LEVEL
M68FC SR109 MIXER MIXER
AUX LEVEL
MIXER MIXER TOTALaII CWNNELS
LlNE OUT OR
PHONES OUT
MIXER MIXER
PHONES
MIXER MIXER ON
,
M6"Tv
,
600Ll
LlNE OUT
MIXER
FIGURE
11.
MIC
LEVEL
TOTAL.11 CHAP:NELS
LlNE LEVEL
SR109
LlNE LEVEL
SRlOS
SRlOS (NO EWALlZATlON
SRIO,
MlXE R
;$
ADDITIONAL MIXER INPUTS
TOTAL: I
TOTAL I2 CHANNELS
,
,
M67
TOTAC. I2 CHANNELS
(NO EOUAUZATI ON ON MlXER
I
CHANNELS
INPUTS)
INPUTS1
Page 16
Page 17
LlNK
OUT
SR1Os
MIXER
LINK
OUT
SR1Os
MIXER
LlNE LEVEL
FIGURE
LINE
LEVEL
LlNE
LEVEL
RESISTORS ARE CARBON COMP., 1/2 W.5%
13.
RESISTIVE
NETWORK
1 I I I
I
I
I
I
I I I
BALANCED
I BRIDGING
I
L
-- - - - -
-
-J
REDUNDANT MIXERS
AMPLIFIER
POWER
AMPL
INPUT
POWER
D D
SR109
MlXER
FIGURE
SRllO
MONITOR
MlXER
ACC OUT
AUX LEVEL
14.
STEREO TAPE RECORDING
SRllO
MONITOR
MlXER
L
-
STEREO
RECORDER
R
-
-
I
TAPE
REMOTE VOLUME CONTROL
A remote volume control may be constructed for adjust­ing the output level at a considerable distance from the Mixer. For remote control up to
15m (50 ft), obtain a linear­taper potentiometer with knob (any value from 1000 to 2500 ohms), a standard phone plug, and a length of
single-
conductor, shielded microphone cable (such as Belden
#8401, #8410, or #8411). Connect the potentiometer and plug as shown in Figure
15A, Page
13,
and connect the
phone plug to the Mixer LlNK OUTPUT Jack (21).
If hum or noise is encountered with the above set-up, it
may be necessary to provide a two-wire control. Using the
same potentiometer, obtain two standard phone plugs and
twice the desired length of single-conductor, shielded microphone cable. Connect the potentiometer and plugs
ing tape channel input; an omnidirectional unit suspended from the ceiling will pick up the full acoustic output of the instruments.
An ideal method of recording the is to use two method allows the
SR110 Professional Monitor Mixers. This
SR109 output to be used for the PA
SR109 output in stereo
system. Connect the SRllOs as shown in Figure 14, Page 13, with the output of one of the tape recorder and the other
SR110 feeding the left input
SR110 feeding the right.
Note that the controls of the SRllOs permit spatial po-
sitioning ("panning" from left to right) and also allow dif­ferent level settings to be used on the recording as op­posed to the PA level. Spatial channel assignment or positioning is accomplished as follows: If the
SR109 chan­nel 1 input is to be recorded on the left tape channel, set the left level and leave the right at (both left and right), adjust both
SR110 channel 1 volume control for the proper
SR110 channel 1 volume control
0. If the second tape input is to be recorded "centered" SR110 channel 2 volume
controls to the same setting. Note that these two controls combine the functions of record level and panning or
positioning.
SR109 instrumental channels that are set at a low level for PA use with respect to vocal channels should be set higher on the SRllOs to provide a proper recording bal­ance. Once the
SR110 levels are set, the SR109 provides
the "mix" for both PA and tape recording.
An expansion of the above method may be used to re-
cord 4-channel (quadriphonic) sound. In this-method, four
SRllOs are connected to the four tape recorder inputs, and adjustments are made as described above.
@
SRlOS
@
SRlOS
MIXER
-
-
0
SRIOS
MIXER IN
LlNK
OUT
FIGURE
--
I
-
-
--
--
LlNK
15.
,\
WHITE
BLACK
REMOTE VOLUME CONTROL
r-------7
I
"
L
---------
I
I
I
I I
I
J
Page 18
as shown in Figure 158, Page 13, and plug the control assembly into the
(22) Jacks.
For distances over 15m (50 ft) or for permanent instal­lations where hum or noise may be encountered, use low-capacitance, two-conductor, shielded cable
den #8412 or #8422). Connect as shown in Figure 15C,
Page 13, and use a metal box to contain the potenti-
ometer. The cable shield must be connected to the metal
box containing the potentiometer, to the common con­ductor (black), and not to the sleeve connections of the
LlNK OUTPUT (21) and LlNK INPUT
(Bel-
phone plugs. IMPORTANT: To avoid hum caused by a ground loop, do not ground the metal box to any metal such as electrical conduit, water pipes, heating ducts, or
structural steel.
TELEPHONE LINE SURGE PROTECTION
When using the Mixer to feed a telephone line that may
be subject to lightning-induced voltage surges, the follow-
ing part should be installed across the telephone line to
provide additional protection for output circuit compon­ents: Thyrector, General Electric Part No.
6RS20SPlBl.
SR109
Professional Mixer
SERVICE INSTRUCTIONS
MIXER SERVICE (SEE GUARANTEE, Page
The SR109 Professional Mixer uses components of the highest quality, operating well within their respective rat­ings to assure long life.
WARNING
Voltages in this equipment are hazardous to life. Make all input and output connections before ac power is connected. Refer servicing to qualified
service personnel.
REPLACEMENT PARTS
Parts that are readily available through local electronics parts distributors are not shown on the accompanying Parts List. Their values are shown on the Circuit Diagram (Figure 25, Pages 32-33). Commercial parts not readily available and unique parts are shown on the Parts List and may be ordered directly from the factory.
The commercial alternates shown on the Parts List are not necessarily equivalents, but may be used in the event that direct factory replacements are not immediately available. To maintain the highest possible performance and reliability, Shure factory replacement parts should be
used. When ordering replacement parts, specify the Shure Replacement Kit Number (RKC), description, product model number, and serial number.
FUSE REPLACEMENT
To replace line fuse F1 (with no apparent problems in
the Mixer), disconnect the line cord from the ac source
and remove the rear-panel fuseholder cap. Replace the defective fuse only with a (SR109 only; SR109-2E contains a 0.1A Slo-Blo fuse for
180- to 250-volt operation, or a to 132-volt operation).
3AG-3/16A Slo-Blo fuse
0.2A Slo-Blo fuse for 90-
35.)
CAUTION
If trouble symptoms -overheating, erratic eration, etc. -were apparent before the fuse blew, or if the replacement fuse blows, a quali­fied serviceman should troubleshoot the Mixer carefully to find the source of the trouble. Do not continue to replace fuses until the trouble has been corrected.
The Mixer also contains a wired-in fuse in series with
rear-panel line fuse
becomes necessary, replace only with an identical fuse.
KNOB REPLACEMENT
All front-panel control knobs are pull-off types and are interchangeable with others of the same function. When ordering replacement knobs, be sure to order the proper color-coded type for the desired control.
SERVICE ACCESS
To open the Mixer for servicing, remove the eight Phil­lips head screws securing the top cover and remove the top cover. Rear-panel-mounted parts and the preamplifier assembly may be reached by removing the eight Phillips head screws securing the rear panel, and carefully moving
the rear panel assembly out and downward. Front-panel­mounted parts may be reached by removing the two screws at the top of the cover channels and the four screws at the bottom of the chassis, and carefully moving the front panel assembly out and downward.
LAMP REPLACEMENT
To replace either of the two luminating the VU Meter (MI), carefully raise the metal cli~ assemblv holdina the of; the power suppry printed circuit board biacket. Lift the lamp socket upward, taking care not to crimp or break any associated wiring. Replace the defective lamp and carefully return the lamp assembly to its original position.
To replace either of the two light-emitting diodes (DI,D2) mounted on the front panel, remove the outer
insulating tubing and mounting ring from the rear of the LED. Press against the front-panel portion of the LED en­velope to force it out the back through the mounting clip.
F1 (F2, 3/10A, Slo-Blo). If replacement
#47
lamps (PLl,PL2)
lam^
to be re~laced uoward and
op-
il-
(LED'S)
Page 19
Unsolder both LED gray leads from the Power Supply as­sembly. Remove the Power Supply assembly and (see
VU
Meter Removal, Page 16). Unsolder the LED orange lead from the LIMITER OUT-IN Switch THRESHOLD ADJ Control be replaced). Insert the replacement LED in the front panel and place the mounting ring and insulating tubing over the leads. Solder the orange lead in place, loosely coiling the two LED orange leads together. Replace the VU Meter and Power Supply assembly. Loosely coil the
two LED gray leads together and re-solder them to the
Power Supply ground terminal.
The above is the recommended procedure for LED re-
placement. In an emergency, the LED wires may be spliced
and insulated (with tape or tubing) without removing the VU Meter or Power Supply.
BOARD REMOVAL
The various printed circuit boards are mounted in dif­ferent manners. The following paragraphs describe the best method of removing these boards after wires and cable assemblies have been removed. IMPORTANT: When disconnecting push-on terminals or soldered board con­nections, make sure each wire is identified for proper reconnection. This may be done by affixing a piece of masking tape marked with the connection or terminal letter to each wire.
Wire colors are given in the following table.
Similar wire colors are used in different circuits; make sure proper re-connections can be made. Take care not to bend or break the push-on ter­minals. Remove or replace terminals by grasping the terminal itself; do not pull on the associated
wire.
Letter Wire Color Letter
Brown G/Ch. 6 Orange
Yellow Green
3
Red
Black Brown White/Red
Orange
White Gray Blue Green Yellow Orange
White/Red Brown Black
A B C,D/Ch. 1 C,D/Ch. 2 C,D/Ch.
A
B C D E F
G
H
J
(R10) (depending on which is to
CAUTION
Preamplifier Board
G/Ch.
Equalizer Boards
C,D/Ch. 4
C,D/Ch. C,D/Ch. 6 C,D/Ch. C,D/Ch. 8
Main Board
K
L
M
N
Q
R
S T V
8
5
7
VU
Meter
(S12) or
Wire Color
White Black
Yellow Green
Blue Gray White
Blue White/Purple Gray White/Green Yellow/Red Yellow Purple Orange
Green
Main Board (Cont'd.)
Black White/Red
"1
A A Black AG Red AB White
F
G Black (7)
NOTE:
Refer to Figure 16, Page 16, for the location of each board. The function of each board assembly is defined in the table below.
Board No. Component Numbering
When removing front-panel control retaining nuts with a
Y2"
nutdriver or wrench, be careful not to damage the
black plastic surface.
Remove boards from nylon fasteners by squeezing the upper protruding tab on the circuit board side inward and sliding the board outward and off the fastener. The fast­eners may be removed from the support bracket by squeez­ing both tabs securing the fastener to the bracket and pushing the fastener through the bracket hole. NOTE: When replacing nylon fasteners, be sure the protruding
tab on the circuit board side is oriented towards the top of the chassis. Failure to do so will make future board
removal difficult.
Preamplifier (Board 1): Remove the board from the
seven nylon fasteners (see procedure above) securing the
board to the vertical bracket, disconnect the eight
coded channel output leads, and lift the board up for service access.
Channel Equalizer (Board 2):
boards may be removed by removing the two front-panel
equalizer control knobs and retaining nuts associated with
that channel. The Channel Equalizer Boards are identical and may be interchanged without modification.
Main Board (Board nylon fasteners (see procedure above) securing the board to the vertical bracket, remove the 41 push-on leads, and lift the board upward.
Power Supply (Board 9): Remove the four screws se­curing the board and lift straight up.
White Red White/Green AF
Power Supply Board
Red (5) Green Black
Yellow Gray
Program Mute Board
Green/White E
I
Red
Production variations may result in wire colors differing from those in the table.
Preamplifier Board 100's Equalizer Boards (8) 200's Main Board 300's Power Supply Board 900's Program Mute Board 90's
3):
1:;
AH
ID
Each of these eight
Remove the board from the six
Green
1
Brown Black
Black
Yellow
White Green
color-
Page 20
FIGURE 16. PRINTED CIRCUIT BOARD AND PARTS LOCATION
Program Mute (Board 0): Remove the board from the four nylon fasteners securing the board to the vertical bracket and lift upward.
LIMITER INTERNAL ADJUSTMENT
To adjust the limiter function following replacement of
circuit components, set the MASTER Volume Control
(R9) to full clockwise. With the LIMITER Switch (S12) in the OUT position, turn on the TONE
OSCillator (Rl) (with all other microphone inputs full counterclockwise) and adjust channel 1 Volume Control to produce a VU Meter
(MI)
reading of 0 VU with the VU RANGE Switch (S13) set to
+4. This provides Output Connector adjust the THRESHOLD ADJ Control output by 1 dB on the VU Meter (to
internal LED potentiometer
+4 dBm (f1.8 dBV) at the LlNE LEVEL (Jl). Set the LIMITER Switch to IN and
(R10) to reduce the
+0.8 dBV). Adjust the
(R379) so that the LIMITER In-
dicator Lamp (Dl) just begins to light.
OVERLOAD INDICATOR CHECK
Set up as for Limiter Internal Adjustment and set the
LIMITER Switch
PHONES Jack, listen to the tone with a 600-ohm
(S12) to OUT. Connect headphones to the
LlNE OUT­PUT load, and increase the channel 1 volume. The OVER­LOAD Lamp
(D2) should light 2 dB before distortion can
be heard on the headphones.
VU METER REMOVAL
If the VU Meter (MI) requires replacement, remove it as follows. Remove the top cover. Remove the two screws at the top of the cover channels and the four screws at the bottom of the chassis, and move the front panel out and downward. Remove the hex nuts, wire leads and washers
from both meter terminals. Loosen the 1-inch screws in the meter retaining brackets at either side of the meter
until the brackets slip off the screws in the sides of the meter. Carefully pass the meter assembly out through the
front panel. To replace the meter, reverse the above steps, taking care to engage the slots in the meter retaining brackets with the screws in the sides of the meter. Tighten the 1-inch screws as necessary to retain the meter against the front panel. Reattach the meter leads, and close and secure the front panel. Replace the top cover.
CAUTION
Do not overtighten screws so as to deform meter retaining brackets.
VU
METER CALIBRATION
With the Mixer turned off, the front-panel VU Meter (MI) should read 0 on the lower of the two meter scales. If it does not, adjust the screw below the meter face to obtain the correct reading.
To calibrate the meter, set the VU RANGE Switch
(S13)
Page 21
to +4 and connect a 600-ohm load and an ac voltmeter across the Mixer and adjust the TONE OSC Control MASTER Volume Control (1.228V across 600 ohms) is obtained on the voltmeter.
Adjust potentiometer R355 (VU Calibrate) on the Main
Board until the VU Meter reads
scales.
Note that the VU Calibrate potentiometer range allows the VU Meter to be adjusted to 0 dBm and +8 dBm.
PARTS REMOVAL
Access to certain parts in the Mixer is not always ap­parent due to the large number of parts and assemblies, and the requirements for their placement. The following
information is given to help locate and gain access to these
parts (see Figure 16, Page 16).
Parts mounted on the rear panel may be replaced by re­moving the eight screws securing the rear panel to the chassis and moving the rear panel out and downward.
Parts mounted on the front panel may be replaced by
removing the two screws at the top of the cover channels and the four screws at the bottom of the chassis, and moving the front panel out and downward.
To remove transformers the bottom of the chassis holding the three-board bracket assembly to the chassis. Carefully lift the entire assembly upward, and remove the nut and washer securing the de­sired transformer.
Front panel controls located below the VU Meter (LIMITER Switch S12, THRESHOLD ADJ Control R10, MASTER Volume Control R9, PHONES Level Control R14
and PHONES Jack J15) may be reached by lowering the front panel as described above.
Headphones transformer
removing the Power Supply board and bracket as de-
scribed under Board Removal.
To gain access to channel Volume Control potentiom-
eters
TRANSISTOR AND DIODE REMOVAL
Most transistors and all diodes used in the Mixer are
mechanically supported by their leads. When replacing
these devices, proper lead configurations must be fol-
lowed. Minimum soldering heat (preferably with a low-
wattage soldering iron) should be used to avoid damage
to the device. Be sure to place heat-shrinkable tubing or
"spaghetti" on leads where the original device contained
such tubing. Transistor lead codes are included in the Notes to Circuit Diagram (Figure 23, Page 29). IMPOR­TANT: Be sure to replace ferrite bead rings on those tran­sistor leads where they were removed.
LINE LEVEL OUTPUT (J12-J14). Turn on the
(Rl) and the
(R9) until a reading of +4 dBm
0 on the upper of the two
0 for any output between
TI-T8, remove the five screws at
(MI)
TI0 may be reached by first
R1-R8, lower the front panel.
ohmmeter "plus" probe on the anode end of a diode, and the "minus" probe on the cathode end, the ohmmeter should read approximately 2000 ohms or less. With the meter probes reversed, a reading of about 10,000 ohms or
more should be obtained. If either of these conditions is not
met, the diode should be replaced.
To check transistors, the ohmmeter should be set to the 100- or 1,000-ohm scale. Transistors and diodes must be removed from the circuit before testing. conditions in the following table are met, the transistor may be considered free of any major defect; if any of the following conditions are not met, the transistor should be replaced. See Notes to Circuit Diagram, Figure 23, Page 29, for transistor lead codes.
OHMMETER CONNECTIONS
"Plus" Lead "Minus" Lead Collector Emitter
Emitter Collector Collector Base Emitter Base Base Collector Base Emitter
*Not a significant measurement.
To check LEDs (OVERLOAD or LIMITER), disconnect
the orange LED lead and connect a
resistor between the +30 Vdc supply and the orange LED lead (gray lead is still grounded). The LED should light
with power applied. Replace any LED that does not light.
NOTE: Do not check LEDs with an ohmmeter; the ohm­meter may damage the LED or give erroneous readings.
To check the
impedance ohmmeter (VOM or VTVM), a 1 V2V battery and a 100-ohm resistor. Disconnect the leads to as follows.
1. Connect the ohmmeter across the light-dependent resistor side of greater than 10 megohms.
2.
With ohmmeter connected as above, connect battery and resistor as shown in Figure 17, Page 17. (IM­PORTANT: Connect only as shown to avoid damage
to the LED.) The resistance reading should drop to less than are not met.
opto-isolator (UI) on Board 3, obtain a high-
U1. Resistance reading should be
1000 ohms. Replace
I00
n.
OHMMETER READING
NPN PNP Transistor Transistor
High High High High High Low
Low Low High Low
I-,
1.5-, or 2.2-kilohm
U1 and check
U1
if these conditions
If all
*
ACTIVE COMPONENT CHECKING
Defective transistors and diodes may be located by use of a standard ohmmeter such as a of the ohmmeter must be verified before these checks are
made.
With a known diode orientation, measure the diode re-
sistance in the forward and reverse directions. The lowest
meter reading will establish the probe at the cathode end (schematic symbol arrow points to cathode) as the "minus" probe while the other probe will be "plus." Some ohm­meters "volts plus probe" and "volts minus probe." With the
Ere not polarized in this manner with relation to
Simpson 260. Polarity
1.5V
+,
-=
FIGURE
CATHODE END
(CODED DOT)
17.
OPTO-ISOLATOR TEST
Page 22
SERVICE ILLUSTRATIONS
Immediately following the parts list on the pages that fol-
low are parts location drawings (Figures
24-27),
25,
and an overall Circuit Diagram (Figures
Pages
30
and
32-33).
Once a board has been located
through the parts location photo (Figure
18
16,
to
22,
Page
Pages
24
16),
and
the components on that board may be located from the cor­responding parts location drawing. Foil circuit paths are shown as shaded areas on the drawings. The overall Circuit Diagram (Figures
24
and
25,
Pages
30
and
32-33)
shows all board circuits and chassis-mounted parts.
OPTIONAL ACCESSORIES
The following optional companion unit and accessory
are designed for use with the Shure
SR109
Professional
Mixer:
SRI 10
Professional Monitor Mixer
A1 05A
Carrying Case
SR109
The
and an
mount in a single
SR110
A105A
Monitor Mixer will conveniently
case.
Page 23
NOTE:
SR109
Professional
Mixer
REPLACEMENT PARTS LIST
The commercial alternates shown in the following lists are not necessarily equivalent parts, but are electrically and mechanically similar, and may be used if direct factory replacements are not immediately available.
maintain highest possible performance and reliability, Shure Factory Replacement Parts should be used. insure low noise figure, order transistors from Shure Brothers Inc.
To
To
Reference
Designation
CHASSIS-MOUNTED PARTS AND ASSEMBLIES
Bd.
1
Bd. 2
Bd. 3
Bd. 9
Bd. 0
I
~e;i;gmfnt
I
I
~ty.
I
I
Replacement Kit Consists Of:
part
NO.
I
Printed Circuit-Assembly,
Preamplifier Printed Circuit Assembly, Channel
Equalizer, with HI and LO controls
Printed Circuit Assembly,
Main Board Printed Circuit Assembly,
Power Supply
Printed Circuit Assembly,
Program Mute
Capacitor, Dual
Electrolytic, 1000 Diode Assembly, Light-Emitting Fuse, Ac,
Slo-Blo (SR109)
0.1A for 220V operation,
0.2A for 115V operation, Fuse, Ac, Slo-Blo, 250V
Fuse, Ac, Pigtail, 3/10A, Slo-Blo
Description
pF, 70V
3AG-3/16A, 125V,
(SR109-2E)
I
None
None
None
None
None
None
Monsanto Littelfuse 313.187
Bussman MDL3116
Littelfuse 21 300 Series
Littelfuse 31 5.300
MV5023
'
Parts listed as RKC
RKC
quantities.
in
Connector, Female, 3-pin Audio,
MICROPHONE LEVEL Connector, Phone Jack, 2-Conductor
Single Closed Circuit, INPUT
Connector, Phone Jack, Conductor, Open Circuit, LlNK OUTPUT
Connector, Male, 3-Pin Audio, MIC LEVEL and
Connector, Phone Jack, Open Circuit, LlNE LEVEL Output
Connector, Phone Jack,
3-Conductor, Open Circuit,
PHONES
-
I
-
1
-
ts should be ordered by that kit number. Any orders received for piece parts where
-
95A655
958552
Connector, Female, 11-pin, MONITOR OUTPUT
1
Connector, Female, SWITCHED AC, 500 WATTS MAX.
LlNE LEVEL Output
(SR109 only)
Switchcraft D3F
Input
Switchcraft 12A
LlNK
2-
3-Conducto~
RKC
Kit number is shown will be shipped
Switchcraft 11
Switchcraft D3M
Switchcraft
Switchcraft 1128
Amphenol 126-805
None
128
Page 24
REPLACEMENT PARTS LIST FOR SR109 PROFESSIONAL MIXER
Reference
Designation
J18
L2-L4
MI
MP1
MP2
MP3
MP4
MP5 MP6 PL1 -PL2 Q1 R1
R2-R8
R9
R9
R10
R14
S1-S10
S11 S12 S13 S14 S15
S16
T1 -T8
T9
I
"eg~mfnt
-
-
-
-
-
-
-
-
-
RKC7 RKC55
-
-
-
-
-
-
-
-
-
-
-
-
-
I
Qty.
-
-
-
-
-
-
-
-
-
4 1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Replacement Kit Consists
Part
No.
95A689
80A250
95A615
90D2085
90C2085
9082119
90A1786
39A384 39A345
95A466 86A338
46A051
46A052
46A050
46A074
46A048
46A049
55A119
-
55A120 55B62 55C119
-
55A116
90J2150
51A235
Connector, Spin, AC (MAINS) POWER
Ferrite Bead Ring
Meter Assembly, VU
Knob Assembly, Orange,
HI FREQ EQ Knob Assembly, Red,
LO FREQ EQ Knob Assembly, Grey,
PHONES
Knob Assembly, Black, Individual Channel and MASTER Volume
Nameplate, Write-on Nameplate, Shure Lamp, Indicator, Transistor, Silicon, NPN
Potentiometer, Modified Log, Tandem, Switch, Channel 1 Volume
Potentiometer, Tandem, Channels 2-8 Volume
Potentiometer, Tandem,
with On-Off Switch,
MASTER Volume Potentiometer, Tandem, 50k,
with On-Off Switch, MASTER Volume
Potentiometer, Screwdriver Adjust, 50k, THRESHOLD ADJ
Potentiometer, Linear, 2k, PHONES
Switch, Slide, DPDT, 15 dB ATTENUATOR and
Part of R1 Switch, Slide, TPDT, LIMITER Switch, Slide, DPTT, VU RANGE Switch, Slide, DPDT, PHASE Part of Switch, Slide, DPDT, VOLTAGE
SELECTOR Transformer and Shield Assembly,
Mic Input
Transformer, Line Level
Output
Of:
Description
(SR109-2E only)
6.3V
50k, with TONE OSC
(SR109)
(SR109-2E)
MIC/LINE
R9
(SR109-2E only)
50k,
50k,
Commercial
Alternate
None
Stackpole 57-0181 Ferronics 21-031
API Instruments 361 -2, A-Scale
None
None
None
None
None
None
GE 47
2N3441
RCA
None
None
None
None
None
None
None
None None None
None
None
None
;
J
'
Parts listed as RKC
in RKC quantities.
Kits should be ordered
by that kit
number. Any orders
received for piece parts where RKC Kit number
is shown will be shipped
Page 25
Reference
Designation
PREAMPLIFIER (BOARD
C130, C140, C150, C160, C170, C180, C190, C191
Replacement
Kit No.
"
1)
Qty.
-
-
Replacement Kit Consists
Part No.
51 D228
51A262 51A265 95A632
90A1888
95A429
95A604
1
95A657
50KB104 I Capacitor, Film, 0.1
868629 Capacitor, Electrolytic,
Transformer, Headphone Output
Transformer, Ac Power (SR109) Transformer, Ac Power (SR109-2E) Line Cord, Ac, Grounded,
2.7m (9 ft) (SR109) Line Cord, Ac, Grounded, %Foot,
Single Connector (SR109-2E) Fuseholder, Miniature,
Panel-Mounting Fuseholder, Miniature, Panel-
Mounting (SR109-2E) Lampholder and Bracket
Assembly
1
22pF, 35V
Capacitor, Electrolytic,
4.7 or 5
pF, 35V
Description
(SR109)
Of:
NF,
Commercial
Alternate
None
None None Belden 17408
None
Littelfuse 342014
None
None
Sprague CDE DMF-1 PI-10
Sprague 502D­226G050CE10;
Mallory MTV-25CB35
Sprague 30D-TE1303; CDE NLW-5-50
225P10491;
Capacitor, Electrolytic,
50
p.F, 35V
Capacitor, Electrolytic,
250
pF,
40V
Silicon Rectifier,
Ferrite Bead Ring
Transistor, Silicon, Low Power, NPN
Transistor, Silicon, Low Power, PNP
Transistor, Silicon, NPN
Parts listed as RKC Kits should be ordered by that kit number. Any orders received for piece parts where RKC Kit number is shown will be shipped in RKC quantities.
100V,
Y2A
Sprague CDE NLW-50-50
None
Motorola Stackpole 57-01 80;
Ferronics 21
Motorola 2N5210
Motorola or Fairchild
Motorola 2N5088; TI 2N3711
30D-TE1307;
1
N4002
-0305
2N5087
Page 26
REPLACEMENT PARTS LIST FOR SR109 PROFESSIONAL MIXER
Reference
Designation
Replacement
Kit No.
~ty. I part
Replacement Kit Consists
NO.
I
Of:
Description
I
EQUALIZER (BOARD
C200, C201, C205. C208
Q200, (2201, (2202 TI 2N3711
R204, R208
MAIN BOARD (BOARD
I
I
2)
-
RKC9
-
3)
86A630 Capacitor, Electrolytic,
1-1
1
4
(
86A349
-
46A034
4.7 or 5 ,F, 35V
I
1
Transistor, Silicon, NPN Motorola 2N5088;
Potentiometer, 50k, HI
and LO FREQ EQ
Capacitor, Electrolytic, 22,F, 35V
Capacitor, Electrolytic,
,
F, 35V
50
Capacitor, Electrolytic,
250
,F, 40V
Capacitor, Electrolytic, 1
,F, 25V
Capacitor, Electrolytic,
.1 ,F, 1oov
Capacitor, Electrolytic,
4
,F, 25V
Capacitor, Electrolytic, 100
,F, 25V
Capacitor, Electrolytic,
47
,F,
16V
Silicon Rectifier,
50V, 112A
Sprague 30D-TE1303; CDE NLW-5-50
None
spGgue CDE NLW-5-50
Sprague 226G050CE10; Mallory MTV-25CD35
Sprague 30D-TE1307;
CDE N LW-50-50 None
Sprague CDE NLW-1-25
Sprague CDE DMF-lP1-10
I
None
Sprague Mallory MTA-100F35; CDE NLW-100-25
Sprague 476G016;
Mallory MTV-35CB25 Motorola 1 N4001
Commercial
Alternate
GD-TEI~O~;
502D-
30D-TE1200;
225P10491;
30D-TE1211;
503D-
Diode, Silicon, Computer, 75v
Silicon Zener Diode,
Ferrite Bead Ring
Transistor, Silicon, NPN
Transistor, Silicon, PNP
Parts listed as RKC Kits should be ordered by that kit number. Any orders received for piece parts where in
RKC
quantities.
22
22V, 5%
Motorola 1 N4748A
Stackpole 57-0180; Ferronics 21-031
Motorola 2N5210
RKC
Kit number is shown will be shipped
J
Page 27
REPLACEMENT PARTS LIST FOR SR109 PROFESSIONAL MIXER
Reference
Designation
POWER
SUPPLY
Replacemtent
Kit No.
Qty.
I
RKC65 86A334 Transistor, Silicon, NPN
I
111
-
86A348 Transistor, Silicon, Low
1-1
-
RKC9
RKC12
-
-
1-1
4
1
86A329 Transistor, Silicon,
86A349
86A336
46D033 Potentiometer, look,
1-1
-
(BOARD
9)
1 - 1
86A901
Replacement Kit Consists
Part No.
I
I
I
Power, PNP
I
N-Channel, Field Effect
I
Transistor, Silicon, NPN
Transistor, Silicon, NPN
Potentiometer, 10k, VU Cal
LIMITER Lamp Cal
I
1
Optical Isolator, LED Photoconductor
Capacitor, Electrolytic, 250
p.F,
60V
Of:
Description
Motorola or Fairchild
Motorola 2N5458
Motorola TI 2N3711
I
I
None
Commercial
Alternate
2N5087
2N5088;
PROGRAM
Parts listed as RKC Kits should be ordered by that kit number. Any orc in RKC quantities.
MUTE
(BOARD
I I
0)
1
Capacitor, Electrolytic, 250
p.
F, 40V
Capacitor, Film,
1
IOOV Silicon Rectifier, IOOV, 1 /2A
I
Silicon Zener Diode, 32V, 5%
Transistor, Silicon,
Power, NPN Resistor, Fixed, 2.0 ohms,
1
W.
5%
Capacitor, Film, 1 OOV
Capacitor, Electrolytic, 1000
p.F,
25V
Silicon Rectifier, Transistor, Silicon, NPN
Transistor, Silicon, NPN Relay, Reed, SPST,
24 Vdc
!rs received for piece parts where RKC Kit number is shown will be shipped
.I
pF,
.I
pF,
100V, 1/2A
CDE BR250-50
Sprague CDE DMF-I PI-10
Motorola 1 N4002 Motorola 1 N4752B RCA 40347
None
Sprague 225P10491; CDE DMF-1P1-I0
Sprague TVA-1211
I
Motorola 1 N4002
Motorola
TI 2N3711
I
TI TIS97
None
225P10491;
2N5088;
Page 28
Page 29
FIGURE
19.
BOARD
2:
CHANNEL
EQUALIZER 2247-2/2246-3/587-4
Page 30
Page 31
FIGURE
21.
BOARD
9:
POWER SUPPLY
2210-9/2251-3/591-4
FIGURE 22. BOARD
0:
PROGRAM MUTE
2254415923
Page 32
Page 33
SR109
Professional Mixer
NOTES
GENERAL
Shure part numbers are not shown in the Parts List ac­companying the Circuit Diagram (Figures 24 and 25, Pages 30 and 32-33) if parts are readily available through local electronics parts suppliers. In these instances, the Circuit Diagram shows only the reference designation and value of the standard parts.
All capacitor values are shown in microfarads unless
otherwise designated. All
100 working volts dc or more unless otherwise specified. Electrolytic capacitors are shown in microfarads x volts.
All resistor values are shown in ohms (k = 1000). Re-
sistors are 10% tolerance unless otherwise specified.
Resistors are
Transistor lead codes are shown in Figure 23. Accept-
able replacements are as shown in the Parts List.
The following ground symbols denote:
ChassisGround Circuit Ground Printed Circuit Board Ground
TROUBLESHOOTING
A
general troubleshooting process is as follows: If the
Mixer is completely "dead," check the ac power source,
%-watt unless otherwise specified.
non-electrolytic capacitors are
/$7
_L
-
-
6
TO
CIRCUIT DIAGRAM
B
fuses, and power supply output (30V between pins
G, Board 9). If the indicator lamps are on but the output is distorted, low or not present, apply an input signal as
described under
termine that the input and output voltage to each board as­sembly is correct. If an incorrect ac voltage is found at any board output, perform board as described below to isolate the problem area.
A~
V~~~AGE
~h, numbers
circuit
the following test conditions:
diagram
1. Voltages measured with respect to chassis unless otherwise indicated.
2. Line voltage:
3. Test signal of 1 mV, 1 kHz applied between pins and 3 of connector J1.
4.
Ac voltage measurements may vary 220% from values shown.
5.
Measurements made with ac VTVM of 1 megohm or greater input impedance.
6.
600-ohm load across LINE LEVEL Output Con-
nector J12 (pins 2 and 3).
Ac
Voltage Measurements below, and de-
Dc
Voltage Measurements on that
M~~~~REMENTS
denote
rectangular symbols
the
ac
voltages
120V, 50/60 Hz (SR109)
120V or 240V, 50/60 Hz (SR109-2E)
at
that
0
point
and
de-
on
under
the
2
~Gii-GGq
C
-
Q
I
.qJ
.aBa:a
Q90, Q112. 0122. 9132, Q142. Q152, 991, 0314 0110, 0120, Q302, Q3II, Q900 Q162,Q172, (2182, Q200-'2202, Q130, Q140. Q315.
0307,Q308,Q313, 9317, Q320. Q150, Ql60,
.@
B6
E
QIII, 0131, Q121. Q141, 0151, Q161, Q316, 0318,
0171, 9181. 9 319. Q32l.
0305.
.a;
0301, Q310, 9312, '2303,
B~
C
00;
-1
GATwDRAIN
4306
9
SOURCE
.0
9170, Q180, 9300,
0309.
.a:
a304
OPT0 - ISOLATOR
.Q
'(333
CATHODE
ANODE
do?!!)
UI
ANODE
CATHODE
FIGURE
23.
LEAD CODES
29
Page 34
7. All Equalization Controls in 0 (flat) setting.
8.
All Volume Controls set to maximum (12).
9. Tone oscillator circuit measurements on Main Board (Bd.
3)
made with TONE OSC Switch on
(out). LIMITER Switch in IN position.
10.
4..
Dc voltage measurements may vary &20% from values shown.
5. Measurements made with VTVM of 11 megohms or greater input impedance.
6. Tone oscillator circuit measurements on Main Board
3)
(Bd.
made with TONE OSC Switch on.
DC VOLTAGE MEASUREMENTS
The numbers within elliptical symbols
a
on the
circuit diagram denote the dc voltages at that point under
the following conditions:
1. Voltages measured with respect to chassis unless otherwise indicated.
Line voltage:
2.
120V, 50/60
Hz
(SR109)
120V or 240V, 50/60 Hz (SR109-2E)
3.
No input signal applied.
RESISTANCE MEASUREMENTS
With the ac line cord disconnected from the ac source and the POWER OFF Switch in the OFF position, the following ohmmeter measurements may be made:
1. Transformers may be checked for continuity of each winding.
2. To test transistors and diodes, see Page 17.
3.
To check LEDs, see Page 17.
4. To check opto-isolator, see Page 17.
FIGURE 24. SR109-2E POWER SUPPLY CIRCUIT DIAGRAM
81227-11-1
Page 35
FIGURE
25.
SR109 PROFESSIONAL MIXER CIRCUIT DIAGRAM
Page 36
MAIN
BOARD
FIGURE 25. SR109 PROFESSIONAL MIXER CIRCUIT DIAGRAM
33
Page 37
SR109
Professional Mixer
CONDENSED OPERATING INSTRUCTIONS
1. Set all switches and controls to OFF or 0.
2. Connect PROGRAM OUTPUT (LINE or MICRO­PHONE LEVEL) to power amplifier, broadcast line
feed, etc. Connect speakers to power amplifier.
Connect headphones to PHONES Jack.
3. Connect sources (microphones, tape recorders, etc.) to INPUT Connectors. Set Channel 7 or 8 MIC/LINE Switches as necessary.
4. Connect external signal-processing equipment (compressor, equalizer, etc.) to LlNK Jacks. (To connect two Mixers, connect LlNK OUT Jacks together.) Connect ac line to ac source.
5.
Turn on POWER Switch and allow one to two min-
6.
warmup time.
utes
ARCHITECTS' AND ENGINEERS' SPECIFICATIONS
The Mixer shall be a self-contained 90- to 132-volt, 50 to 60 Hz, line-operated, all-silicon transistor mixing ampli­fier with preamplifiers and controls to mix eight independ­ent low-impedance microphone input signals.
Each input channel in the Mixer shall have independent HIGH-FREQUENCY and LOW-FREQUENCY controls, position zero to 15 dB ATTENUATOR Switch and rotary­motion level control. The 7th and 8th input channels shall
each have an additional input switch to select the de-
sired input level (MIC or LINE).
The PROGRAM OUTPUT circuit shall have a 600-ohm balanced line level output rated at 1% distortion with a minimum clipping level of
and a low-impedance, balanced, microphone-level output at a level 50 dB below the LlNE LEVEL output. A PHASE switch shall be provided to reverse the phase of both the
LlNE and MICROPHONE LEVEL outputs.
The program channel shall have a rotary motion MAS-
TER LEVEL control, and a 76.2 mm (3 in.) illuminated
+4,
VU meter with a 0, Switch.
A pair of LlNK Jacks shall be provided in the program
circuit to allow connection to external equipment such as a compressor, limiter, equalizer, additional mixer or con­sole, etc.
The Mixer shall have a PHONES level control and a
transformer-coupled headphone (PHONES) output.
The Mixer shall have a voltage gain of 87 maximum microphone input sensitivity of 0.1 millivolts for
+4 dBm program output.
a
The microphone input clipping level, with a zero
ator setting, shall be 4.5 millivolts minimum with the level
control at maximum and shall increase to 100 millivolts minimum with the level control near minimum.
*
All specifications apply to
180-250
volts; no switched
+8 dBm VU METER RANGE
SR109-2E
AC
receptacle is provided.
+I2 dBm at less than
%3 dB and a
except: operating voltage is
two-
+I9 dBm
attenu-
90-132
7. Set 15 dB ATTENUATOR Switches to preliminary position for type of material to be used
speech or instrumental music, -15 for "hard" rock music).
8. Set VU METER RANGE Switch for present applica-
9. Set MASTER Volume Control to 6. With source in-
10. Adjust HI and LO
11. Turn on LIMITER and adjust-THRESHOLD ADJ
0 for PA, +4 for recording, or
tion:
cast. put, raise Channel Volume Control for desired
sound level. Readjust ATTENUATOR Switch if
necessary.
trols as necessary. Control if desired.
FREQuency EQualization Con-
+8
for broad-
*
The Mixer shall contain a peak-responding adjustable output limiter with an in-out switch and an indicator lamp that flashes when the limiter threshold is exceeded. An overload lamp, which operates only when the limiter
is not activated, shall indicate when the output clipping level of the Mixer is exceeded.
An 11-pin accessory monitor output connector shall
provide for connection to one or more Shure fessional Monitor Mixers to provide separate monitor mixes for stage monitoring (foldback), multi-channel tape recording, or stereo broadcasting.
The Mixer shall be enclosed in a metal housing designed for rack-mounting in a standard 19-inch (483 mm) audio equipment rack, or mounting in an accessory vinyl-covered wood portable case.
The Mixer dimensions shall .be 133
height, 483
depth. The weight shall be not more than 7.7 kg (17 Ib).
The Mixer shall have a built-in tone oscillator and a level control built into the channel 1 program circuit. A POWER on/off switch shall also be located on the front panel. A switched ac receptacle rated for 500 watts maximum load shall be provided.
The MICROPHONE INPUT connectors shall be female professional audio type. The LlNK Jacks, and tho PROGRAM LlNE LEVEL OUTPUT Jacks shall be %-inch phone jacks. One PROGRAM LlNE LEVEL OUTPUT con­nector and the MIC LEVEL OUTPUT connector shall be three-pin male professional audio type. The headphone
(PHONES) connector shall be a three-circuit
jack to be used with either mono or stereo phones with an
impedance of 4 ohms or higher.
Any Mixer not meeting all of the above specifications shall be deemed unacceptable under this specification. The Mixer shall be a Shure Model
or
mm (19 in.) in width, and 232 mm (9% in.) in
SR109.
SR110 Pro-
mm (5Y4 in.) in
%-inch phone
(0 for
three- in
GUARANTEE
This Shure product is guaranteed in normal use to be free from electrical and mechanical defects for a period of one year from date of purchase. Please retain proof of purchase date. This guarantee includes all parts and labor. This guarantee is in lieu of any and all other guar­antees or warranties, express or implied, and there shall be no recovery for any consequential or incidental damages.
SHIPPING INSTRUCTIONS
Carefully repack the unit and return it prepaid to:
Shure Brothers Incorporated
Attention: Service Department
1501 West Shure Drive
Arlington Heights, Illinois 60004
If outside the United States, return the unit to your dealer
or Authorized Shure Service Center for repair. The unit
will be returned to you prepaid.
35
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