PROEL acdt120 User manual

INSTRUCTION MANUAL
PA Combo Amplifiers
ACDT120 / ATT120

1. IMPORTANT SAFETY INSTRUCTIONS
CAUTION: To reduce the risk of electric shock do not remove cover (or back panel). No
user serviceable parts inside. Refer servicing to qualified personnel only.
WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to
rain or moisture.
This symbol is intended to alert the user of the presence of uninsulated
dangerous voltage within the product enclosure that may be of sufficient
magnitude to constitute a risk of electric shock to persons.
This symbol is intended to alert the user of the presence of important operating
and maintenance (servicing) instruction in the literature accompanying the
appliance. Please carefully read the owner’s manual.
INSTRUCTIONS:
All safety and operating instructions should be read before the product is operated.
Retain these instructions:
All safety and operating instructions should be retained for future reference.
This owner’s manual should be considered as a part of the product and it must accompany it
every time, and delivered to the new user when this product is sold. In this way the new owner will
be aware of all the installations, operating and safety instructions.
Heed all warnings:
All warnings on the product and in owner’s manual should be adhered to.
Heed all warnings.
Follow all instructions:
All operating and user’s instructions must be followed.

Sentences preceded by symbol contain important safety instruction. Please read it carefully.
DETAILED SAFETY INSTRUCTIONS.
Water and moisture:
This apparatus should not be used near water (i.e. bathtub, kitchen sink, swimming pools,
etc.)
Ventilation:
This apparatus should be placed in position that doesn’t interfere with correct ventilation. This
unit, for example, should not be placed on a bed, sofa cover o similar surfaces that could
cover ventilation openings, or placed in a built-in installation, such a bookcase or a cabinet
that could block air flow trough ventilation openings.
Heat:
This apparatus should be placed away from heat sources, like radiators, heat registers, stoves
or other products (including amplifiers) that produce heat.
Power sources:
• This apparatus should be connected only to power source type specified in this owner’s
manual or on the unit.
• If the supplied AC power cable plug is different from wall socket, please contact an
electrician to change the AC power plug.
Grounding or Polarization:
• All precautions must be observed in order to avoid grounding or polarization defeating.
• Unit metal parts are grounded through the AC power cord.
• If the AC power outlet doesn’t have grounding, consult an electrician for outlet grounding.
Power cord protection:
The power cord should be routed in a way it will not be walked on or pinched by items placed
upon or against it, paying particular attention to cords at plugs, convenience receptacles and
wall outlet.
Cleaning:
• You can clean the unit with a compressed air flow or a wet cloth.
• Don’t clean the unit using solvents like trichloroethylene, thinners, alcohol, or other fluids
with very strong volatility and flammability.
Non use periods:
The unit AC power cord should be unplugged from the outlet if it’s unused for a long period.

Objects or liquid entry inside the unit:
Be careful that no objects fall or liquid is spilled inside the unit through ventilation openings.
Safe power line use:
• Keep firmly the plug and the wall outlet while disconnecting the unit from AC power.
• If the unit will not be used for a long period of time, please unplug the power cord from AC
power outlet.
• In order to avoid unit power cord damages, please don’t strain the AC power cable and
don’t bundle it.
• In order to avoid unit power cord damages, please be sure that the power cord is not
walked on or pinched by heavy objects.
Unit relocation:
Before any unit relocation please control the unit is turned off. The power cord must be
unplugged by the wall outlet, and all the connections wires should be disconnected.
Don’t open this unit:
Don’t attempt to open or to repair this unit by yourself. For any problem solution not described
in this owner’s manual, please refer to qualified personnel only or consult us or your National
Distributor. Any improper operation could result in fire or electric shock.
Damages requiring services:
• Don’t attempt to do operations not described in this user’s manual.
• In following cases please refer to an authorized maintenance center or skilled personnel:
- When the unit works improperly or it doesn’t work at all.
- If power cord or plug are damaged.
- If liquid has spilled, or objects have fallen into the unit.
- The unit has been exposed to rain.
- The unit doesn’t operate normally o it exhibits a marked change in performance.
- If the product has dropped or it has been damaged in any way.
Maintenance:
The user shouldn’t attempt maintenance operation not described in this user’s manual. Every
maintenance operation should be done by qualified personnel only.
IMPORTANT SAFETY INSTRUCTIONS:
• Install this unit following owner’s manual instructions.
• Don’t install, connect or disconnect power supply when the unit is powered, otherwise
there’s an high risk of electric shock.
• Don’t open the unit, there are no user serviceable parts inside.
• If you detect a particular smell from the unit, please immediately turn it off and disconnect
the AC power cord.
• Don’t block the unit ventilation openings.
• Avoid using this unit in overload for a long period.
• Don’t force commands (switches, controls, etc.)

• To obtain good speakers wire contacts, please tighten the screw terminals firmly.
• For safety reason, don’t defeat the grounding connection. Grounding is useful for user
safety.
• Use only connectors and accessories suggested by the manufacturer. .
• This unit should be placed in a rack (see INSTALLATION) and kept far from:
 Wet places
 Direct exposure to heat sources (like sun light)
 Non properly ventilated places
• Disconnect the power cord during storms or when the unit is not used.
• In order to prevent fire and electric shock risks, it’s necessary to keep the unit far
from sprinkling and drops. Please don’t put cups, vases or other object containing liquids
over the unit. In case of interferences from source signal, THD value will raise over 10%.
Don’t place this unit in a bookshelf o in other places with small room.
• PROEL S.P.A. is not responsible for any damage that occurs due to a wrong unit
installation.

Thank you for choosing one of Proel products, and for your confidence towards
our brand, synonymous of professionalism, accuracy, high quality and reliability.
All our products are CE approved and designed for continuous use in
professional installation systems.
2. DESCRIPTION
This unit is designed for speech, music, paging and sound reinforcement
applications.
FEATURES
• State-of-the-art design and manufacturing accuracy.
• Wide frequency response: 50 Hz – 15KHz ± 3 dB.
• Low distortion and low noise level.
• Digital tuner, with 14 FM memories and 7 AM memories, and CD
player sections (ACDT120) built-in. Each section has its own
independent power switch and volume control.
• Digital tuner, with 14 FM memories and 7 AM memories, and
cassette recorder (ATT120) sections built-in. Each section has its
own independent power switch and volume control.
• Master volume control.
• Bass and Treble tone controls.
• LED level indicator.
• Four balanced microphone inputs, two aux inputs. (displaced on
rear panel).
• Mic 1 unbalanced microphone input with automatic mute. This
circuit allows to mute all the active program sources - CD, Tuner,
Tape, AUX.
• Five outputs – three constant impedance outputs (4Ω, 8Ω, and
16Ω) – two constant voltage outputs (70 V, and 100 V).
• Tape recorder line level output.
• AC Power selector (115 – 230 V).
• 24 V DC emergency power.
• Protection circuits.

3. FRONT PANEL DESCRIPTION
fig. 1
1. Power On/Off switch.
2. Output MASTER volume control.
3. Output LED meter.
4. Digital tuner volume control.
5. Digital tuner section.
6. Digital tuner On/Off switch.
7. Tone controls (BASS and TREBLE).
8. MIC 1 – 4 volume controls.
9. MIC 1: 1/4" jack unbalanced low impedance (30 – 600 Ω) input.
10. AUX 1 and AUX 2 volume controls.
11. CD player/Cassette recorder section.
12. CD player/Cassette recorder volume controls.
13. CD player On/Off switch.

4. REAR PANEL DESCRIPTION
fig. 2
1. IEC AC power socket, with fuse-holder.
2. AC power selector (115 V – 230 V).
3. 24V DC emergency power terminal.
4. Emergency DC power switch (24 V DC).
5. MIC 1 - MIC 4 balanced inputs.
6. RCA external equipments connectors (Tuner, CD player, etc.).
7. FM antenna connector.
8. AM loop antenna.
9. Constant impedance/constant voltage speakers output.
10.Grounding terminal.
5. INSTALLATION
1. 24V DC emergency power connection (generator or battery).
• Use terminals # 3of fig.2.
• In case of AC power fault or black out, the unit will be powered by 24
V DC, with automatic and silent switchover to backup power.
Note: to activate this feature switch # 4of fig. 2 must be set to ON
position.

• We inform our customers that if DC power supply is supplied by a
battery, the unit won’t be able to recharge the battery.
• When the amplifiers is powered by 24 V DC, amplifier nominal power
will be reduced by 20%.
2. Input connections
• MICROPHONE CONNECTION:
Despite the kind of microphones you’re using, please always use a
shielded wire.
Please see the following drawings for details about the different
wirings:
Unbalanced low impedance microphone:
Balanced low impedance microphone:
Unbalanced 1/4" TS jack connection.

!
• PRIORITY FEATURE
When MIC 1 input is active, the unit will automatically mute all the
other program sources.
3. Output connections
Attention
To prevent the risk of electric shock, never touch amplifier outputs when
the amplifier is turned on.
To access to speaker connection terminals (fig. 2 ref. 9) remove the
protection cover unscrewing the screws.
CONSTANT IMPEDANCE LINE
To use this amplifier with a constant impedance line (4Ω, 8 Ω, and
16 Ω), please connect the COM terminal to the negative post of your
speaker, and connect the proper impedance terminal to positive post
(fig. 2 ref. 9).
• To obtain the best performances, total speakers impedance
connected to the line should be equal to the amplifier output
impedance.
• The speakers power sum should not be lower than the amplifier
output power.
• We suggest you to don’t use long cables. Anyhow, for longer
distances application use a thicker cable.
CONSTANT VOLTAGE LINE
If you’re using a constant voltage line, connect either the 70, or 100V to
the “+” side of speaker system, and connect COM to “-“ side of the
speaker (fig. 2 ref. 9).
• Speakers should have a transformer of the same voltage
developed by the amplifier.
• Speakers power sum should not exceed amplifier maximum
output power.

6. OPERATIONS:
1. Pressing the POWER switch in “I” position the unit is turned on,
pressing the POWER switch to “0” position the unit is turned off.
2. BASS control modifies signal lower frequencies output (up to 10 dB of
boost or cut). Set this control level by personal taste and ambient
acoustic character.
3. TREBLE control modifies signal higher frequencies output (up to 10
dB of boost or cut). Set this control level by personal taste and
ambient acoustic character.
4. CD, AUX 1, AUX 2, and MIC inputs have an independent volume
control and MIC 1 has priority over all the other inputs.
5. Turning clockwise MASTER volume control, the playback level will
raise, turning it counter clockwise it will be lower.
6. TUNER SECTION
• PROGRAM LISTENING. Radio station can be manually or
automatically selected.
• AUTOMATIC STATION SEARCH. This function can only be used
with a strong signal without interferences.
a. Press the BAND key to select desired band (AM or FM).
b. Pressing the UP or DOWN key for about 5 seconds, automatic
station search starts, and it will stop reaching a radio station with
a strong signal.
• MANUAL SEARCH. If radio station signal is weak, automatic station
search will not be possible, so it’s necessary to do manual radio
station search.
a. Press the BAND key to select desired band (AM or FM).
b. Pressing UP or DOWN key for about 2 seconds, automatic
station search starts, and it will stop after reaching a radio station,
despite of its signal strength.

Now it’s possible to do a more accurate tuning, in fact with a short
pressure of the UP or DOWN keys, you will get a minimum
frequency shift (50 KHZ step).
• MEMORY. The receiver allows you to store up to 14 FM (numbered
1 to 7 and 9 to 15) radio station and 7 AM radio station as well.
These memories can be recalled using front panel 1-7 keys.
Table key/stored radio station
Key
FM 1 2 3 4 5 6 7
1 2 3 4 5 6 7
Key pressed once
Displayed
Number
9101112131415Key pressed twice
Key
AM 1234567
Displayed
Number 1234567Key pressed once
• STORING RADIO STATIONS.
After tuning the desired station, to store a music program press the
ME (memory) key (once for memories from 1 to 7, twice for
memories from 9 to 15) followed by the number chosen to store the
radio station. There are only 7 memories available for AM band.
NOTES.
a. If during automatic or manual search the tuner reaches the band
end, the tuner will continue searching starting from the beginning
of that band.

b. When a new radio station is stored in an already used memory,
the former radio station will be substituted by the new radio
station.
c. This unit is able to keep the stored memories for about two
weeks, even if no mains power is applied.
7. CD PLAYER. (Model ACDT120 only)
a. Pressing this section power switch (fig. 1 ref.13) the display is lit
and the CD player is ready for use.
b. Pressing the open/close key the CD tray opens, now you can
insert the CD and close the tray by pressing again the same key.
After some seconds the display will show the CD track content,
now it’s possible to begin the CD playback pressing play/pause
key.
Functions:
• OPEN/CLOSE. Press this key to open/close the CD tray.
• PLAY/PAUSE. This key starts/stops track playback.
• LEVEL. This control serves to set CD player volume.
• STOP. This key stops CD playback.
• B.SKIP/REV.
Pressing this key once, playback starts from the beginning of
current track.
Pressing it twice, playback starts from the beginning of
previous track.
Keeping this key pressed, the CD will be in fast reverse play.
• F.SKIP/FF.
Pressing this key once, playback starts from the beginning of
next track.
Keeping this key pressed, the CD will be in fast forward play.

• REPEAT. Pressing this key once, the current track is in
continuous playback. Pressing it twice, the whole CD is in
continuous playback. Pressing it three times the CD player will
resume to normal playback.
• PROG. It’s possible to program the tracks you wish to play in a
sequence of your choice. Pressing this key the display flashes,
using the arrows keys you select the track you want to insert
into the program, then confirm it using again the PROG key.
Repeat the same procedure to add other tracks to program.
Pressing PLAY the CD player will begin programmed playback.
Note: It’s possible to insert in a program up to 18 tracks.
8. CASSETTE RECORDER (Model ATT120 only)
a. Press the EJECT key to open the cassette door, please insert the
cassette to be played with open side facing down, as showed in
the following picture.
b. Close the cassette door by pressing it forward softly.
c. With the cassette side A towards the user, pressing the FPLAY
key side A playback will start, while pressing the RPLAY key side
B playback will start.
Functions:
• MODE. For each pressure of MODE key, the unit will
sequentially change in operating modes: Continuous Cycle /
Cyclic / Normal.
- Continuous Cycle. The unit cyclically
reproduces both cassette sides.
-Cyclic. The unit reproduces once both
cassette sides.
- Normal. Playback is stopped at the end of
current side.

• FF. Pressing this key, the tape will be Fast Forwarded. Pressing
this key during reproduction the unit will Cue Fast Forward the
tape, allowing the user to find the desired song.
• REV. Pressing this key, the tape will be Rewind. Pressing this
key during reproduction the unit will Cue Rewind the tape,
allowing the user to find the desired song.
• STOP. This key stops playback and/or cassette fast forward
and/or rewind.
• REC. Pressing this key the REC indicator is lit and the direction
indicator flashes in both directions. Pressing now the FPLAY
key recording will begin on the side turned towards the user, the
direction indicator will stop flashing and it will show the
corresponding direction. Pressing the RPLAY key the function
will be the same but recording will be done on the other side of
the cassette.
7. TROUBLESHOOTING
Problem Solution
LED is not lit when the POWER
switch is ON.
• Check that AC plug is firmly
connected.
• Check that the fuse is properly
working.
Ventilation fan is not working. • Check that AC plug is firmly
connected.
• Check that the fuse is properly
working.
No sound or only a very low-level
sound is heard.
• Check that inputs have been properly
selected.
• Check proper speakers connection.
Output signal is discontinuous,
with hum and noises.
• Check power supply is correct.

There’s no output signal on one or
both channels.
• Check the speakers wires and overall
line.
• Check pilot signal has a proper level.
CD player display doesn’t turn lit. • Check that CD player own POWER
switch is ON.
No output signal from CD player. • Check CD disk is clean and not
defective.
Output radio signal is distorted,
there are many interferences or a
very low-level sound is heard.
• Check antenna proper connection.
• Check the antenna proper
orientation.
• Check the antenna is of the right type
to receive desired radio station and
band.
Output radio signal is
discontinuous, with hum and
noises.
• It frequently depends on neon light,
lamps, engines and electric
appliances generated interferences.
LED level indicator shows signal
but no signal is output.
• Turn off the unit for some seconds,
thus resetting the protection circuit
that probably has been turned on and
turn the unit on again.
• Check all input/output connections.
• If the problem remains, please
contact a qualified maintenance
centre.
CD player display shows an error
message (ER..).
• Open and close the CD player tray.
• Cut the volume, turn off the CD
player section for some seconds then
turn on the CD player section again.
• If the problem remains, please
contact a qualified maintenance
centre.

8. Technical specifications
Model ACDT120/ATT120
Output power RMS / MAX 120W / 180W
Constant impedance
outputs
4Ω, 8Ω, 16Ω
Constant voltage outputs 70V, 100V
Inputs connectors
MIC 1: front Unbalanced 6.3 mm jack input 600Ω, -60 dB
MIC 1~ MIC 2: Balanced XLR inputs 600Ω, -60 dB
AUX 1: 10 KΩ, -15 dB
AUX 2: 20 KΩ, -20 dB
RECV: 4,7 KΩ, 650 mV
Outputs connectors
4Ω, 8Ω, 16Ωon terminal board
70V, 100V on terminal board
SEND: 600Ω, 1V
Frequency response 50Hz – 15 KHz
Harmonic distortion Less than 3% @ 1000Hz, at full RMS power
Signal to noise ratio 80 dB
Tone controls BASS: ±10 dB @ 100Hz
TREBLE: ±10 dB @ 10KHz
Controls
INPUT 1 ~ INPUT 4 volume control
AUX 1 volume control
AUX 2 volume control
TONES (BASS TREBLE)
MASTER output volume control
TUNER volume control
CD player volume control
CASSETTE volume control
Indicators Power on LED
Output power level LED ladder
AC power 230 V AC - 115 V AC
DC power 24 V DC
AC Power consumption 295 W @ 120 W RMS power
DC Power consumption 8 A @ 120 W RMS power
Dimensions (W x H x D) 450 mm x 100 mm x 335 mm – 17,7 x 4 x 13.2 in.
Weight ACDT120: 12 Kg – 26.5 lbs / ATT120: 11 Kg – 24.1/4 lbs.
Color Black

9. Typical hookup diagrams

Unit use as pre-amplifier.
Unit use as amplifier.

Unit external equalization for radio, CD player, and microphone signals.
Note
The unit is supplied with a removable jumper between rear panel RECV
input and SEND output.