Valcom Clarity SM120 User manual

1 947602
CAUTION: To reduce the risk of electric shock,
Do not remove cover.
No user serviceable parts inside.
Refer servicing to qualified service personnel.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
This symbol indicates that dangerous
voltage constituting a risk of electric
shock is present within this unit.
This symbol indicates that there are
important operating and maintenance
instructions in the literature accompanying
this unit.
Issue 4
SM120
RACK MOUNT 120 WATT AMPLIFIER
INTRODUCTION
These instructions contain the specifications and
information necessary to install, operate and
maintain the SM120, 120 Watt Mixer-Amplifier.
The SM120 provides up to 120 Watts of audio
power for voice paging or background music
systems.
SPECIFICATIONS
Access Methods
Paging and Sound Reinforcement Systems
Stand Alone Background Music Systems
Features
Active mix or Priority override on inputs
(override is voice operated)
Rack Mount
Mic 1/Tel on Input 1, plus 3 standard
MIC/AUX inputs
Volume control for each input
Master Volume, Bass and Treble Controls
Overload limiting circuit protection
Screw terminals for all connections
Power "ON" indicator
Clipping and Fault indicators
8 Ohm, 25 and 70 Volt selectable output
Tone generator (Warble or Continuous)
Optional external volume control
Dimensions and Weight
17.0" W x 12.0" D x 1.75" H
(43.23cm W x 30.5cm D x 4.4cm H)
Weight: 5.1 lbs. (2.3 kg)
Nominal Specifications
Wattage Output 120 Watts Peak
Type Outputs 8 Ohm or 25V or 70V
Frequency Response 20 to 20kHz +/-2dBm
Distortion < 2% @ 1kHz Rated Output
Number of Inputs 4 (1 Mic/Tel Line,
3 Mic/Aux)
Voice Switch Sensitivity 31dBm
Mic Input Impedance 600 Ohms Balanced
Mic Input Sensitivity 1.0mVRMS
Tel Line Input Impedance 600 Ohms
Tel Line Sensitivity 70mVRMS
Aux Input Impedance 10K Ohms
Aux Input Sensitivity 200mVRMS
Line Out Impedance 10K Ohms
Line Out Level 1VRMS
Nominal Power Requirements
Input Voltage: 85-265VAC
Current @ 120VAC: 0.28A Typical
Environment
Temperature 0 to +40° C +32° to +104° F
Humidity 0 to 85% non-precipitating
Precautionary Designations
WARNING-To Reduce The Risk Of Fire Or
Electric Shock. Do Not Expose This
Apparatus To Rain Or Moisture.
•AVERTISSEMENT - Afin de réduire les
risques d'incendie ou de décharge
électrique, évitez d'exposer le système à
la pluie ou à l'humidité.
•Apparatus shall not be exposed to
dripping or splashing and no objects filled
with liquids, such as vases, shall be
placed on the apparatus.
•L’appareil ne doit pas être exposé à des
égouttements et éclaboussures et aucun
Objet Rempli de liquide, comme vase, ne
doit être place sur l’appareil.

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INSTALLATION
FCC Information
This equipment has been tested and found to
comply with the limits for a Class A digital
device, pursuant to Part 15 of the FCC Rules.
These limits are designed to provide
reasonable protection against harmful
interference when the equipment is operated
in a commercial environment. This
equipment generates, uses and can radiate
radio frequency energy and if not installed
and used in accordance with the instruction
manual, may cause harmful interference to
radio communications. Operation of this
equipment in a residential area may cause
harmful interference in which case the user
will be required to correct the interference at
his own expense.
General Mounting Information
A) Elevated Operating Ambient - If installed in a
closed or multi-unit rack assembly, the operating
ambient temperature of the rack environment may be
greater than room ambient. Therefore, consideration
should be given to installing the equipment in an
environment compatible with the maximum ambient
temperature (Tma) specified by the manufacturer.
B) Reduced Air Flow - Installation of the equipment in
a rack should be such that the amount of air flow
required for safe operation of the equipment is not
compromised.
C) Mechanical Loading - Mounting of the equipment
in the rack should be such that a hazardous condition
is not achieved due to uneven mechanical loading.
D) Circuit Overloading - Consideration should be
given to the connection of the equipment to the
supply circuit and the effect that overloading of the
circuits might have on overcurrent protection and
supply wiring. Appropriate consideration of equipment
nameplate ratings should be used when addressing
this concern.
E) Reliable Earthing - Reliable earthing of rack-
mounted equipment should be maintained.
Particular attention should be given to supply
connections other than direct connections to the
branch circuit (e.g. use of power strips).
F) Equipment only suitable for mounting at heights
less than or equal to 2m (6.56’).
DESIGN
The SM120 amplifier may be used to operate 8
Ohm, 25 Volt or 70 Volt speakers and horns.
The SM120 will actively mix all inputs or will
provide priority inputs. If priority input is
selected, the Mic/Tel input will override all inputs
that are active (refer to Table 1 in the Operation
Section for the override sequence). When the
SM120 is in the priority mode, the switching is
voice operated (no contacts are required).
The SM120 amplifier has a master volume
control plus a separate volume control for each
input. Bass and treble controls are also
provided.
The mixer-amplifier contains a limiting circuit for
protection against short circuits or impedance
mismatches. The unit will shut down in the
event of a trouble condition and reactivate
automatically when the condition is corrected.
INSTALLATION
General
Figure 1 shows volume control locations. Figure
2 shows output terminal strips and switches on
the back of the amplifier as well as typical
connections to the mixer-amplifier.
All connections on the back of the SM120 are
accessed by removing the rear cover. Replace
the cover after connections have been
completed.
IMPORTANT SAFETY INFORMATION
CONSIGNES DE SÉCURITÉ IMPORTANTES
1. Read these instructions.
Lisez ces instructions.
2. Keep these instructions.
Conservez ces instructions.
3. Heed all warnings.
Respectez tous les avertissements.
4. Follow all instructions.
Suivez toutes les instructions.
5. Do not use this apparatus near water.
Ne pas utiliser cet appareil près de l'eau.
6. Clean only with dry cloth.
Nettoyer avec un chiffon sec.
7. Do not block any ventilation openings. Install in accordance with the manufacturer’s
instructions.
Ne pas bloquer les ouvertures de ventilation. Installer formément aux instructions du
fabricant.
8. Do not install near any heat sources such as radiators, heat registers, stoves or other
apparatus (including amplifiers) that produce heat.
Ne pas installer à proximité de sources de chaleur telles que radiateurs, registres de
chaleur, poêles ou autres appareils (y compris les amplificateurs) produisant de la chaleur.
9. Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug
has two blades with one wider than the other. A grounding type plug has two blades and a
third grounding prong. The wide blade and the third prong are provided for your safety. If
the provided plug does not fit into your outlet consult an electrician for replacement of the
obsolete outlet.
Ne pas contourner le dispositif de sécurité de la fiche polarisée ou de mise à la terre. Une
fiche polarisée possède deux lames dont une plus large que l'autre. Une fiche de terre a
deux lames et une troisième broche de mise à la terre. La lame large et la troisième
broche sont fournies pour votre sécurité. Si la fiche fournie ne rentre pas dans votre prise,
veuillez consulter un électricien pour le remplacement de la prise obsolète.
10.Protect the power cord from being walked on or pinched particularly at plugs, convenience
receptacles and the point where they exit from the apparatus.
11.Only use attachments/accessories specified by the manufacturer.
N'utilisez que des fixations / accessoires spécifiés par le fabricant.
12. Use only with the cart, stand, tripod, bracket or table specified
by the manufacturer or sold with the apparatus. When a cart is
used, use caution when moving the cart/apparatus combination
to avoid injury from tip-over.
Utilisez uniquement avec le chariot, stand, trépied, support ou table spécifié par le
fabricant ou vendu avec l'appareil. Quand un chariot est utilisé, Soyez prudent lorsque
vous déplacez l'ensemble chariot / appareil pour éviter des blessures dues au
renversement.
13. Unplug this apparatus during lightning storms or when unused for a long period of time.
Débranchez cet appareil pendant les orages ou lorsqu'il n'est pas utilisé pendant une
longue période de temps.
14. Refer all servicing to qualified service personnel. Servicing is required when the
apparatus has been damaged in any way. Such as when the power supply cord or plug is
damaged, liquid has been spilled, objects have fallen into the apparatus or the
apparatus has been exposed to rain or moisture and does not operate normally or has
been dropped.
Confiez toute réparation à un personnel qualifié. Une réparation est nécessaire lorsque
l'appareil a été endommagé de quelque façon. Par exemple lorsque le cordon
d'alimentation ou la fiche est endommagé, du liquide a été renversé, si des objets sont
tombés dans l'appareil ou le appareil a été exposé à la pluie ou à l'humidité et ne
fonctionne pas normalement ou s'il est tombé.

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Mounting
The SM120 is designed for rack mounting.
Make certain the unit is not mounted near heat
sources or strong magnetic fields. Verify control
and terminal strip accessibility. It is
recommended that a minimum of 1 Rack Unit
(1.75”) of space above the SM120 be empty for
adequate ventilation. See Figure 3.
Telephone System 600 Ohm Page
Port Connection
The SM120 can be used with a PBX Page Port
using the TEL connection. Connect the page
port Tip to TEL (+) and the page port Ring to
TEL (-) as shown in Figure 4.
NOTE: Interface devices are required when
connecting to outside C.O. Lines, PABX
extensions or single line telephones.
MIC Connections
The SM120 has connections for up to four low
impedance microphones. All of the connections
are made the same for MIC1, MIC2, MIC3 or
MIC4. Connect the positive lead of the
microphone to the MIC (+) terminal, negative
lead of the microphone to the MIC (-) terminal
and the shield to MIC “C” terminal. See Figure 5.
Auxiliary Connections
The SM120 has connections for up to three high
impedance auxiliary devices, such as a tuner,
tone generator, etc. All of the connections are
made the same for AUX1, AUX2 or AUX3.
Connect the auxiliary device’s positive lead to
the AUX (+) terminal and the device’s negative
lead to the AUX (-) terminal, as shown in Figure
6. If the Auxiliary device provides a shield
conductor, it may be connected to terminal “C”.
Tone Connections & Volume
The SM120 has a built-in tone generator that
can create either a Warble tone or a Single tone
output to the speaker using a contact closure.
The tone will be generated while the contact is
closed and stop when the contact is opened.
Either or both tones may be used. If used
simultaneously, the Single tone will have priority.
For the Warble tone, connect one lead from a
contact closure (relay, push button, etc.) to the
“W” terminal and the other lead to the “C”
terminal. For the Single tone, connect the
closure leads to the “S” and “C” terminals. See
Figure 7. The two terminals marked (+) and (-)
are not used.
The volume of the generated tones can be
adjusted using the small knob labeled “Volume”
on the rear panel.
Remote Volume Control Connections
An optional remote volume control may be
connected to the SM120. The control is
connected to the V-, R and V+ terminals (see
Figure 8). The two terminals marked (+) and (-)
are not used. The recommended Valcom part
number is SM-VC.
Priority Switch Setting
The SM120 has two modes of operation for the
input connections, either Mixing or Priority. In
Mixing mode, all inputs are mixed together. In
Priority mode, only one input is active at any
time. The selection is made using switch #4, as
shown in Figure 9b. If switch #4 is ON, the
SM120 mixes all inputs. If switch #4 is OFF, the
inputs are prioritized as shown in Table 1. The
SM120 must be power cycled for switch setting
changes to be recognized.
Output Switch Settings
The SM120 output is selectable as either 25
Volt, 70 Volt or 8 Ohm as shown in Figure 9a.
For 25 Volt output, set #1 and #2 OFF.
For 70 Volt output, set #1 ON and #2 OFF.
For 8 Ohm output, set #1 and #2 ON.
Speaker Connections
When the 8 Ohm output is used, standard two
conductor speaker wire can be used (18-20
AWG determined by load). If the 25V or 70V
output is used, two conductor shielded cable is
recommended for speaker connections. 8 Ohm,
25V or 70V speakers are connected to the
terminal labeled "Speaker".
NOTE: When shielded cable is used, the
shield should be connected to the Ground
lug located on the rear of the SM120.
The terminal labeled "Line Out" provides a line
level signal suitable for passing audio to other
devices that accept a signal up to 1 VRMS.
Amplifier Setup
During initial system set up, it is recommended
that the individual gain controls be set 1/4 turn
clockwise and the master volume control be set
1/2 turn clockwise.
NOTE: Double-check all amplifier
connections before the AC power cord is
plugged in.
The power indicator will illuminate when the AC
power cord is plugged in.

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OPERATION
The SM120 provides two modes of operation,
either active mix or priority override.
When the amplifier is in the active mix mode,
signals on all inputs are mixed and sent to the
speakers. When the priority input is selected, a
signal on the MIC/TEL input will override all other
active inputs (see Table 1 for override
sequence). The override is voice activated and
does not require the use of an external relay or
contact closure. The separate gain controls on
the unit allow adjustment of the volume levels of
each input.
A clipping light is provided on the front of the
unit. This light will illuminate when the output
signal exceeds the power rating of the amplifier.
Table 1 - Override Sequence
Input
Priority Level
Mic 1/TEL
Mic 2/Aux 1
Mic 3/Aux 2
Mic 4 /Aux 3
1
2
3
4
NOTE: Level 1 is highest priority.
TECHNICAL ASSISTANCE
When trouble is reported, verify power is being
supplied to the unit and there are no broken
connections. If a spare unit is available,
substitute a spare unit for the suspected
defective unit.
Assistance in troubleshooting is available from
the factory. Call [phone] and press 1 for
Technical Support or visit our website at
http://www.valcom.com
Valcom equipment is not field repairable.
Valcom, Inc. maintains service facilities in
Roanoke, VA.
Should repairs be necessary, attach a tag to the
unit clearly stating your company name, address,
phone number, contact person and the nature of
the problem. Send the unit to:
Valcom, Inc.
Repair & Return Dept.
5614 Hollins Road
Roanoke, Va. 24019-5056
WARRANTY
Warranty information may be found on our
website at www.valcom.com/warranty.
TROUBLESHOOTING CHART
PROBLEM
POSSIBLE SOLUTION
No Output
1. Verify AC power is being supplied to the unit.
2. Verify that input signal is present at amplifier connection.
3. Verify all speaker wiring (no opens, shorts or grounds).
Distorted output
1. Check input wiring for proper polarity connections.
2. Verify that speaker load does not exceed amplifier rating.
3. Verify input signal does not exceed input voltage rating.
4. Verify all speaker wiring (no opens, shorts or grounds).
Override does not operate
1. Verify input signal is at proper level.

5 947602
SM120
by Valcom
FAULT CLIP ON
MIC1
TEL
46
010
MIC2
AUX1
46
010
MIC3
46
010
MIC4
46
010
BASS
46
010
TREBLE
46
010
MASTER
46
010
AUX2 AUX3 Clarity
CLASS 2 WIRING
SPEAKER
AUX1 / MIC2
VOLUME
TONE
+
-
LINE
OUT
AUX3 / MIC4REMOTE
+
-
AUX2 / MIC3 TEL / MIC1W C S
V- R V+ +-C - +
+-C - +
AC POWER 115VAC/60HZ/75W B C
A C
Figure 1. Front view
Figure 2. Rear View
Figure 3. Mounting

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FIGURE 4
PAGE PORT
600 OHM
TEL
+-
MIC
FIGURE 5
MICROPHONE
C+
-
FIGURE 6
AUX DEVICE
(OPTIONAL)
AUX
+-C
TONES
WC
FIGURE 7
S
CLOSURE
CONTACT
123 4
O
N
(#1 & #2 OFF)
25 VOLT
123 4
O
N
(#1 ON & #2 OFF)
70 VOLT
12
FIGURE 9a
3 4
O
N
(#1 & #2 ON)
8 OHM
OUTPUT SELECTION SWITCH
123 4
O
N
(#4 ON)
MIXING
123 4
O
N
(#4 OFF)
PRIORITY
INPUT SELECTION SWITCH
FIGURE 9b
REMOTE
v- v+
REMOTE
VOLUME CONTROL
R
GREEN
YELLOW
ORANGE
SM-VC
SM120

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TONES
W = WARBLE
C = COMMON S = SINGLE
RELAY, CONTACT CLOSURE, ETC.
SM120
Clarity
FAULT CLIP ON
MIC1
TEL
46
010
MIC2
AUX1
46
010
MIC3
46
010
MIC4
46
010
BASS
46
010
TREBLE
46
010
MASTER
46
010
AUX2 AUX3
PBX
Page Port
(Tel)
AUX AUX AUX
Microphone
Microphone
Microphone
Microphone
or
Choice
of:
or or
SM120 MIXER AMPLIFIER
by Valcom
Typical Installation Block Diagram