The PS 230 is a dual channel speaker station designed forSpecial attention has been paid to the intelligibility of
use in both portable and fixed intercom systems.speech. By applying low noise/high speed opamps, a
It incorporates a loudspeaker and a gooseneckspeech presence filter and a specially developed high
microphone and provides full duplex communicationspower bridged headphone amplifier, communication is
within an ASL intercom system. The PS 230 RM modelvery comfortable even in environments with high backhas a small built-in electret microphone.ground-noise level. There is a separate amplifier for the
loudspeaker.
Each channel has a Volume (listen level) control, a Talk
and Call button with LED indicators and a two-stageThe unique ASL CALL system provides both a flashing red
sidetone trimmer.LED and a very distinctive and characteristic sound signal.
Smooth operation is guaranteed with the CALL button.
The unit is equiped with a limiter for the gooseneckOnly a slight touch makes the red LED flash, whilst holding
microphone, allowing the user to speak close into thethe button for two seconds will activate the CALL sound
microphone without giving rise to overload and distortion.signal. The volume of the sound signal (buzzer) can be
Loudspeaker dimming is automatic when the microphoneadjusted at the front panel.
is active. Private conversation may be carried out via the
headset connector with a headset or telephone handset.Fully electronic switching increases reliability and allows
When a headset is connected, both the gooseneckfor :
microphone and speaker are disabled automatically.-'soft' microphone ON switching, latched or momentary
-remote Mic Mute facility.
As an option, a XLR-6 headset connector can be fitted-automatic speaker attenuation (adjustable), when the
allowing the user to hear channel A at the left headset canmicrophone is activated.
and channel B at the right headset can.
2.0UNPACKING
The shipping carton contains the parts below:After unpacking the unit please inspect for any physical
damage to the unit, and retain the shipping carton and
*The PS 230relevant packing materials for use should the unit need
*User manualreturning.
If any are missing, contact your dealer.If any damage has occured, please notify your dealer
immediately so that a written claim can be initiated. Please
ASL has taken great care to ensure this product reachesalso refer to the guarantee section of this manual.
you in flawless condition.
3.0INSTALLATION
This PS 230 will form part of an existing or new intercomThe PS 230 is fully protected against mis wiring (reverse
system, and connection to it is straightforward. There arepower) or short circuit in the interconnect cables.
no separate power connections, or batteries to install, as
the necessary DC voltages are derived from the intercomA special kit is available for mounting the PS 230 in a 19"
master station or power supply, via the intercomrack, taking 2U of rack space.
connection cable.
To connect the PS 230 to the intercom system, use
professional flexible microphone cable with 2 wires and 1
screen only. Connect the system intercom cable to the
LINE connector socket on the side panel. Finally, when
private conversation is desired, connect the listening
headset plug to the HEADSET connector on the front
panel.
These knobs adjust the listen level for speaker andThese trimmers (one for each channel) control the
headset. The level of each channel can be adjustedrejection in the high frequency range. It compensates
separately.the capacity of the interconnecting cables. It prevents
the speaker from feeding back into the microphone
2 TALK buttons
These buttons allow you to talk to each channel
separately or simultaneously.
Any Talk button activates the gooseneck or headsetThis trimmer allows you to dim the speaker automatimicrophone, the large green LED at each channelcally, when the gooseneck microphone is switched on.
indicates if the microphone is switched on to thatIt prevents:
channel.-unit feedback if sidetone rejection is not sufficient.
Latched switching:
When a TALK button is pressed quickly, the
microphone will be switched on, and is electronically
latched. When pressed again, the microphone will be
switched off.
When the microphone is latched on, it can be muted by-inject an audio signal on the selected intercom
a mic mute from a PRO Series master station or powerchannel.
supply.-turn up volume.
Momentary switching:
When a TALK button is pressed and held, the
microphone will be switched on, and when released,The speaker attenuator has no effect when a headset
will be switched off.is used.
(unit feedback).
6 SPEAKER ATTENUATOR trimmer
-system feedback or a 'hollow' sound when the
microphones of other speaker stations on the same
channel are activated simultaneously.
Adjustment procedure :
-switch off TALK buttons.
-activate microphone and adjust the desired amount
of attenuation.
3 CALL buttons7 BUZZER VOLUME trimmer
These push buttons activate the call system, for eachThis trimmer adjusts the volume of the internal buzzer,
channel separately.which is located behind the front panel.
A momentary push will send a call signal to all stationsThe buzzer is activated if you press the CALL button of
connected to the intercom channel and the call LEDSthe PS 230 or a CALL button of any other station (on
will start flashing.the channel to which the PS 230 is connected), longer
Press and hold the button for 2 seconds will activatethan 2 seconds and the buzzers are not muted (at the
the call buzzer, if not muted.master station or power supply).
After the CALL button is released the LEDS will
continue to flash for further 2 seconds.
4 SIDETONE LEVEL trimmers
These trimmers (one for each channel) control the levelmust have a can impedance of 200 ohms (or greater),
of your own voice as you hear it in the speaker oror each 400 Ohms minium when in parallel.
headset. It prevents the speaker from feeding back intoThe headset microphone may be of the dynamic or
the gooseneck microphone.electret type.
Adjustment procedure for all sidetone trimmers :Pin assignments :
-set trimmer in start position : fully clockwise.1. Shield mic. (GND)
-switch off the microphones of all connected2. mic. +
(speaker !) stations.3. phones +
-switch on the microphone of the PS 230.4. phones -
-turn up volume.
-speak into the headset microphone.When connecting a headset, the speaker and
-adjust the listen level by turning the sidetonegooseneck microphone will be disabled automatically.
trimmer.
The operating area is between fully clockwise andheadset connector for binaural use.
minimum level. Adjusting the sidetone does not affectChannel A will then appear on the left can and channel
the level of your voice as it is heard by other stations.B on the right can.
8 HEADSET connector
A XLR-4 type connector for the connection of a local
headset when private conversation is desired. This
The PS 230 can optionally be equipped with a XLR-6
A high quality electret noise canceling microphone.A high quality loudspeaker driven by a 3.5 Watt
A limiter prevents the microphone preamplifier fromamplifier.
clipping when speaking close into the microphone.The speaker is automatically disabled when a headset
The gooseneck microphone is automatically disabledis used.
when a headset is used.
5.0SIDE PANEL CONNECTORS
11 LINE connector channel A
12 LINE connector channel B
These XLR-3 connectors are for connecting the
PS 230 to the intercom system.
Pin assignments :
1. 0 V / ground shield
2. +30 V power wire
3. audio wire
6.0INTERNAL CONTROLS
Inside the unit there are two trimmers to adjust the mic
gain of the gooseneck microphone and the headset
microphone separately.
These internal trimmers can be reached as follows :The two trimmers are labeled :
-remove the screws of the bottom plate.GOOSE for the gooseneck microphone
-slide the plate to one side and take it out.HEADS for the headset microphone.
For the PRO Series Intercom system the interconnecting
cables are of the shielded two-conductor microphone
cable type and the intercom line connectors are of the
XLR-3 type. Audio and Call signals are on XLR pin 3, DC
power is on XLR pin 2. XLR pin 1 is connected to the
shield of the cable which functions as the common return
for audio and power.
Since the audio signal is transferred in an
way, certain rules have to be obeyed when installing the
cables of an intercom network. This is to avoid earth loops
and to minimize power loss and the possible effect of
electromagnetic fields.
These rules are:
Use high quality (multipair) cable.
For interconnecting user stations, power supplies andWhen two (multi channel) units in a network are
accessories in an ASL Intercom network, use highconnected by more than one cable, make sure that
quality shielded two-conductor (minimum 2x 0.30 mm2)these cables are parallel to each other over the whole
microphone cable only. distance between those units. When using multipair
In case of a multi channel intercom network, use highcable, parallelism is ensured in the best possible way.
quality microphone 'multipair' cable only, each pair
consisting of two conductors (minimum 2x 0.15 mm2)
with separate shield. Multipair cable should also haveAlways avoid that cables are making a loop. So-called
an overall shield. 'ring intercom' should not physically be cabled as a
Use flexible cables.
Use flexible single and multipair microphone cablepower supply position) as the centre of the star.
instead of cable with solid cores, especially when the
cable is subjected to bending during operation or
installation.Keep intercom cables away from high energy cables,
Separate cable screen to XLR pin 1.
The screen of each separate microphone cable and/orIntercom cables should cross high energy cables at an
the screen of each single pair in a multipair cable,angle of 90( only.
should be connected to pin 1 of each XLR-3 connector.Intercom cables should never be in the same trunking
Do not connect this cable screen to the metal housingas energy cables.
of the connector or to metal wall boxes (outlets).
See page 8 for Earthing Concept.
Cable trunks, connection boxes and overall
multipair cable screen to clean earth.
Metal cable trunks, metal connection boxes and overalluser stations are placed.
multipair cable screen should be interconnected and,
at one point (the 'central earthing point') in the intercom
network only, be connected to a clean earth or a safetyThe ASL power supply may be connected to the mains
earth.power outlet to which other audio equipment is
See page 8 for Earthing Concept.connected. Avoid using mains outlets which also power
Keep metal connection boxes and cable trunks
isolated from other metal parts.
Metal housings for intercom cables and connectorscontact us. Please send us a block diagram of the
should be mounted in such a way that they are isolatedplanned network with a list of all user stations and their
from other metal cable and connector housings andpositions, and we are happy to advise you on cabling
from any other metal construction parts.lay out.
unbalanced
¼
¼
Keep cables parallel as much as possible.
Avoid closed loops.
ring. All cable routes should have a 'star' configuration,
with the central earthing point (usually close to the
Keep cables away from electromagnetic sources.
e.g. 110/220/380V mains power or dimmer controlled
feeds for spotlights.
Place power supply in a central position.
In order to avoid unacceptable power losses, place the
power supply as close as possible to where most
power consumption occurs or, in other words, most
Connect ASL power supply to a 'clean' mains outlet
dimmer controlled lighting systems.
In case of more complex installations, don't hesitate to
ASL's PRO Series offers a complete two way ('full duplex')
communications system. current (at 30 V DC)40 mA quiescent
Users of the system are connected via a 'party line'.80 mA signalling
Master stations (with built-in power supply), beltpacks,220 mA at max. output + signalling
speaker stations and power supplies are interconnected
via standard microphone cable. One wire is used as an
audio line, one as a power line and the screen of the cablegooseneck microphone typenoise cancelling electret
functions as earth/return.headset mic. impedance200 ohms
Current drive is used for signal transfer. Each stationpresence filter+6 dB at 5 kHz
utilises a current amplifier to amplify the microphone signalfrequency response200 Hz - 13 kHz (-3 dB)
and place it on the common audio line where, due to theV electret mic+9 V DC
constant line impedance (situated in the power supply
between XLR pin 3 and 1), a signal voltage is developed
which can be further amplified and sent to headphones ormax. load200 ohms
loudspeakers.max. output levelnormal 14 V rms (200 ohms)
This principle has three advantages:max. output powernormal 0.5 W rms (each can)
-the use of a single audio line allows several stations tobinaural 0.16 W rms (each can)
talk and listen simultaneously.
-due to the high bridging impedance offered by each
station, the number of stations 'on line' has nospeaker impedance50 ohms
influence on the level of the communications signal.max. output power1.3 W rms
-power and audio to the intercom stations use the same
cable.
The Call signal is also sent as a current on the audio line.output impedance> 150 Kohms
It develops a DC potential over the line impedance which
will be sensed by each station and interpreted as a Call
signal.rejection0 - 30dB adjustable
POWER CONSUMPTION
MIC. PREAMP
gain40 dB - 70 dB (adjustable internally)
HEADPHONES DRIVER AMP
binaural 8 V rms (400 ohms)
SPEAKER DRIVER AMP
INTERCOM LINE DRIVER
max. output current3 mA rms
SIDETONE
9.0 GUARANTEE
This unit is warranted by ASL Intercom to the original enduser purchaser against defects in workmanship and
materials in it's manufacture for a period of one year from
date of shipment to the end-user.
Faults arising from misuse, unauthorised modifications or
accidents are not covered by this warranty. If the unit is
faulty it should be sent in it's original packing, to the
supplier or your local ASL dealer, with shipping prepaid. A
note must be included stating the faults found and a copy
of the original suppliers invoice.
THIS PRODUCT WAS DESIGNED, DEVELOPED AND
MANUFACTURED BY:
AMPCO SOUND LAB BV
MAARSSEN (UTRECHT) HOLLAND.
BUZZER
max. SPL100 dBA
DIMENSIONS AND WEIGHT
width230 mm
height88 mm
depth42/48 mm sloping
weight1.3 Kg
GENERAL SYSTEM SPECIFICATIONS
intercom line impedance350 ohms (1kHz)
2.2 Kohms (DC)
intercom line audio levelnom. -18 dBu
max. +4 dBu
dynamic range80 dB
call send signal+2.8 mA
call receive signal threshold+2.4 V DC
supply voltage+30 V DC (12 V to 32 V)
mic mute power interrupt time0.1 sec
Note: 0 dBu = 775 mV into open circuit
ASL reserves the right to alter specifications without further