McLelland CA1250 User manual

Right Left Right Left Right Left
Right Left
Right Left Right Left
CA1250
12 CHANNEL
6 ZONE
INTEGRATED AMPLIFIER
CA1250

2
• Explanation of Graphical Symbols
The lightning flash with arrowhead symbol, within an equilateral triangle, is
intended to alert you to the presence of uninsulated “dangerous voltage” within
the product’s enclosure that may be of sufficient magnitude to constitute a risk
of electric shock to persons.
The exclamation point within an equilateral triangle is intended to alert you to
the presence of important operating and maintenance (servicing) instructions in
the literature accompanying the product.
CAUTION: TO PREVENT ELECTRIC
SHOCK, MATCH WIDE BLADE PLUG TO
WIDE SLOT, INSERT FULLY.
ATTENTION: POUR EVITER LES
CHOCS ELECTRIQUES, INTRODUIRE
LA LAME LA PLUS LARGE DE LA FICHE
DANS LA BORNE CORRESPONDANTE
DE LA PRISE ET POUSSER JUSQU AU
FOND.
RISK OF ELECTRIC SHOCK
DO NOT OPEN
RISQUE DE CHOC ÉLECTRIQUE
N'OUVREZ PAS
CAUTION: To reduce the risk of electric shock, do not remove cover (or
back).
No user-serviceable parts inside. Refer servicing to qualified service
personnel.
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with a dry cloth.
7. Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
8. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
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 or 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.
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.
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.
13. Unplug this apparatus during lightning storms or when unused for long periods of time.
14. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug
is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally,
or has been dropped.
15. The apparatus shall not be exposed to dripping or splashing and that no objects filled with liquids, such as vases, shall be placed on the apparatus.
16. CAUTION: Servicing instructions are for use by qualified service personnel only. To reduce the risk of electric shock, do not perform any servicing other than
that contained in the operating instructions unless you are qualified to do so.
17. WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture.
PORTABLE CART WARNING
Important Safety Instructions

3
Table of Contents
Important Safety Instructions............................................................................................................ 2
Table of Contents ............................................................................................................................... 3
Introduction......................................................................................................................................... 4
Features............................................................................................................................................... 5
What’s Included .................................................................................................................................. 5
Front Panel Features.......................................................................................................................... 6
Rear Panel Features........................................................................................................................... 7
IR Remote Control.............................................................................................................................. 9
Installation......................................................................................................................................... 10
Wiring Infrastructure........................................................................................................................ 11
Speaker Wire ............................................................................................................................... 11
Multi-zone Audio (4/8 Ohms) ....................................................................................................11
Multi-room Audio - Stereo or Bridged (4/8 Ohms) ....................................................................11
70V/100V..................................................................................................................................11
Connections...................................................................................................................................... 12
Speaker Connections ................................................................................................................. 12
............................................................................................................................... 12
 ..................................................................................................................................... 12
70V/100V................................................................................................................................. 13
Audio Connections ..................................................................................................................... 14
Zone Line IN ............................................................................................................................ 14
Audio Bus IN ........................................................................................................................... 14
Audio Bus OUT ....................................................................................................................... 14
Control Connections................................................................................................................... 15
Zone IR IN .............................................................................................................................. 15
Zone Mute ............................................................................................................................... 16
Zone Status OUT .................................................................................................................... 16
Zone Line/Bus Trigger IN ........................................................................................................ 16
Master Control IN..................................................................................................................... 17
Master Control OUT................................................................................................................. 17
RS232 I/O................................................................................................................................ 17
Settings ............................................................................................................................................. 18
70/V100V High Voltage Speaker Output ................................................................................. 18
................................................................................................ 18
Stereo/Bridged Zone Setting ................................................................................................... 18
Limiter...................................................................................................................................... 18
Remote Bypass ....................................................................................................................... 19
Voltage Select/Fuse................................................................................................................. 19
Operation........................................................................................................................................... 21
Voltage Controlled ................................................................................................................... 21
IR Controlled............................................................................................................................ 21
RS232 Controlled .................................................................................................................... 22
RS232 Commands............................................................................................................................ 23
RS232 Queries .................................................................................................................................. 25
RS232 Settings ................................................................................................................................. 27
 ................................................................................................................................... 29
Limited Warranty .............................................................................................................................. 30

4
Introduction
Congratulations and thank you for purchasing the McLelland CA1250 12 Channel 
The CA1250 is, at its core, a twelve channel audio distribution amp....but it can also do so many
other things.
C
4 Ohm/8 Ohm zones (30W/channel @ 8 Ohms; 50W/channel @ 4 Ohms); but it can also be
configured for six stereo 70/100V zones (30W/channel); or three high powered bridged zones(100W
@ 8 Ohms). By the way, the CA1250 can be configured for any combination of stereo 4 Ohms/ 8
Ohms, 8 Ohms bridged and 70/100V zones all at the same time!
And there’s more. Each zone can be controlled via IR or RS232 for ON/OFF, Input, Volume/Mute,
Treble/Bass and Left/Right Balance. The RS232 section is bi-directional with an easy to configure
command structure. The CA1250 can be configured to automatically send zone status updates or
respond to queries to confirm zone status and settings. Commands for volume, treble/bass and
balance can be specific values or step commands depending upon the control application.
The CA1250 has an Audio Bus IN that can be manually selected by IR commands, RS232
commands or voltage trigger. The voltage trigger will switch a zone to the Audio Bus IN as long
as there is voltage present on the zone Line/Bus Trigger IN. When the voltage is cut, the zone
automatically switches back to the zone Line IN. Great for momentary switching to an audio page on
the Bus IN!
Each zone has a Mute Trigger IN that will mute zone audio when voltage is present on the Mute
Trigger IN. When the voltage is cut, the zone audio output resumes.
Each zone has a 12VDC Status or Control OUT that can be used to activate a zone specific volatge
controlled device or otherwise indicate zone ON/OFF status.
Each zone has a -20dB audio limiter to prevent incidental peaks from becoming consequential
damage.
The CA1250 features a Remote Bypass switch that allows/blocks IR and RS232 commands from
select zones for zones that are intended to be user controlled or set and not messed with.
Finally, the CA1250 has a 110~120V/220~240V select switch allowing it to be used just about
anywhere there is AC Voltage.
The CA1250 is also rack mountable and comes with removable rack ears.
The McLelland CA1250 12 channel x 50W audio distribution amp...ready for anything... anywhere.
Please read and follow the instructions in this guide to assure proper installation and maximum
performance of your new McLelland CA1250.

5
Features
•
Bus input (unbalanced)
•

• All zones are independently controllable via RS232, IR and voltage trigger lines
• Each zone has -20dB Audio Limiter
• Each zone has an independent mute trigger input (activated by +3 to +30V DC)
• Each zone has an individual Trigger Output (+12V DC) that coresponds to zone ON/OFF status
• Front panel features “Zone ON” and “Zone Overload” LED indicators for each zone
• Master global Control In (+3 to +30V DC) and Control Out (+12V DC)
• Detachable screw-terminal connectors for global Audio Bus IN/OUT, Zone IR IN, Zone Mute, Zone
Status OUT and Zone Speaker Outputs
• Rack mountable in standard 19" rack (2U height)
• Selectable 110/220 AC volatge
What’s Included
CA1
1 - IR Remote Control
1 - AC Power Cord
1 - User Manual
CAUTION!!!
NEVER CHANGE ANY OF THE FOLLOWING SETTINGS WHEN THE CA1250 IS TURNED
ON OR CONNECTED TO AC POWER:
70V/100V HIGH VOLTAGE SPEAKER OUTPUT

ZONE STEREO/BRIDGED SWITCH
VOLTAGE SELECT SWITCH (110/220VAC)
DOING SO CAN CAUSE SEVERE DAMAGE TO THE CA1250 AND/OR CONNECTED
SPEAKERS. THIS TYPE OF DAMAGE IS NOT COVERED UNDER WARRANTY.

6
21 1
3
1. RACK EARS - Two, optional rack ears. The CA1250 is 2U rack height. If rack mounting, leave

desired.
2. PEAK OUTPUT LEDS - 
volume setting. This is an indication that the volume setting is approaching maximum...not an

a bit to protect the amp and speakers.
3. ZONE POWER LEDs - Six, green LEDs illuminate solid green when a stereo zone is ON. LED
turns WHITE when Zone is OFF.
Front Panel Features

7
Right Left Right Left Right Left
Right Left
Right Left Right Left
12 3 4 5 6 7 8 9
1011121314151617
1. SYSTEM 70/100 VOLT SELECT - One, switch. Slide switch to select between 70V and 100V for a high-
voltage audio distribution system. This setting will affect all zones in 70V/100V mode. Set for 70V when
voltage select is set to 110-120VAC; Set for 100V when voltage select is set to 220-240VAC.
2. ZONE IR, MUTE & STATUS TERMINAL - Six, plug-in screw terminals. Provides connections for zone

IR IN - Connect IR IN & GND to the Emitter OUT on an IR Control system for zone IR control using the
CA1250 IR Remote.
Mute - Connect to a +3 to +30VDC @1mA control voltage to mute the local zone.
Status - Provides a 12VDC 1mA Control OUT to trigger zone specific voltage controlled devices.
3. ZONE SPEAKER TERMINAL- Six, plug-in screw terminals. Each terminal has six connections for different

 Use indicated terminals for high output mono speaker connection. (100W @ 8 Ohms)


Use indicated terminals for normal stereo speaker connections. (30W @ 8 Ohms;
50W @ 4 Ohms)


70V/100V - Use indicated terminals for 70V/100V stereo speaker connections. (30W @ 70V/100V)



4. ZONE LINE/BUS TRIGGER IN- Six, 3.5mm mini jacks. This voltage controlled input switches the zone
audio input from Line IN to Audio Bus IN. When there is no voltage applied, the zone audio input is zone
Line IN. When voltage is applied (+3 to +30VDC @1mA) the zone audio input will switch to Audio Bus IN.
 Six, push buttons. Press to select 8 Ohms/4 Ohms - 70V/100V by
zone. Leave OUT to select 8 Ohms/4 Ohms, press IN to select 70V/100V.
6. MASTER CONTROL IN - One, 3.5mm mini jack. Connect to a +3 to +30VDC @1mA control voltage to turn

7. MASTER CONTROL OUT - One, 3.5mm mini jack. Connect to any voltage controlled device that is to be
turned ON/OFF relative to CA1250 ON/OFF Status. When any zone on the CA1250 is ON the Master
Control OUT will output 11.5VDC@1mA-10VDC@5mA. When all zones are OFF the Master Control OUT
Rear Panel Features

8
is 0.0VDC.
8. POWER ON/OFF SWITCH - One, switch. Set to ON position to turn power to the amp ON. Set to OFF
position to turn power to the amp OFF.
9. VOLTAGE SELECT SWITCH - One, switch. Select either 110V-120V or 220V-240V as appropriate for local

10. AC MAINS - One, three-prong socket. Use the supplied 3-pin ground power cable to connect the unit to an
external AC power supply.
11. FUSE - One, replaceable fuse. For 110V-120V/60Hz use a T10.0AL/250V fuse. For 220V-240V/50Hz use a
T5.0AL/250V fuse.
12. RS232 TERMINAL - One, DB9F terminal. Connect to an automation system or other controller for two-way
communication with and control of the CA1250.
13. REMOTE BYPASS - One, six position DIP switch. Set to OFF to allow IR/RS232 control of the selected
zone. Set to ON to block IR/RS232 control of the selected zone.
14. ZONE LINE IN - Twelve, RCA jacks. Connect to the L & R line level OUTs on an audio source that is to be

15. ZONE AUDIO LIMITER - Six, push buttons. Press to activates a -20dB input limiter, for both channels, to
help reduce the level of accidental audio peaks and clipping distortion by zone. Leave in the OUT position
to pass audio through unprocessed, press IN to activate the input limiter.
16. STEREO/BRIDGED - This switch


information.
Stereo - For stereo signals, leave switch in the OUT (Stereo) position. This applies to all connections in
the 8 Ohm/4 Ohm and 70V/100V configurations.
Bridged -


designed to run safely into such a low impedance (which the CA1250 is not) damage may



17. AUDIO BUS - One, plug-in screw terminal. Mono, unbalanced input. This input will send the Audio IN
signal to all zones switched to Bus using the Line/Bus Trigger IN. It can also send the Bus Audio IN signal
to another CA1250 via the Audio Bus OUT.
Rear Panel Features

9
IR Remote Control
The CA1250 IR Remote Control controls the individual zones on the
CA1250. It can also be used to teach IR commands to a
programmable, integrated IR remote, zone control system or other
IR routing device.

controller or IR router will be necessary for centralized control of the
individual zones. Local zone control can be easily accommodated
with a local IR receiver and an IR Remote.
1
2
3
4
5
6
7
8
7
1. IR LED - 
(infrared) light pulses that are the control codes for the CA1250.
The LED must be pointed at an IR receiver that is connected to
an CA1250 Zone IR IN.
2. MUTE - With audio playing in a zone, press this button to mute
the zone audio output. Press again to un-mute.
3. BUS - Press this button to select the audio source playing
through the Audio Bus IN.
4. LINE - Press this button to select the audio source playing
through the local zone Line IN.
5. TREBLE/BASS - Press the Treble +/- buttons to increase/decrease the accent of high frequencies
in the zone audio output. Press the Bass +/- buttons to increase/decrease the accent of low
frequencies in the zone audio output. Season to taste.
 
C
6. VOLUME - Press the Volume + button to increase zone audio output. Press the Volume - button to
decrease zone audio output.
7. BALANCE L/R - Press the Balance L button to increase volume in the left speaker relative to the
right speaker. Press the Balance R button to increase volume in the right speaker relative to the

C for
additional information.
8. POWER - Press this button to turn the local zone ON. Press again to turn the local zone OFF.

10
Installation
1U Rack Vent Above CA1250
1U Rack Vent Below CA1250
C

adequate cooling.
C
surfaces.

above the top cover. Be sure there are large openings in the shelf below the unit and in the
cabinet to allow the entry of cool air and the escape of warm air.
4. If the cabinet contains other heat generating components or several CA1250’s are being used,
be sure to provide adequate ventilation to dissipate heat the units can generate.
C
and the other heat generating components.
6. When installing the CA1250 in a rack, please use racks that feature a rear support provision.
Adding a single RU (Rack Unit) vent above and below the CA1250 will improve convection in
heavy use applications. [One Rack Unit size = 1-3/4" (44.5mm) in height]. Also try to mount the

7. Be sure to leave adequate space for large bundles of wire and dress them in such a manner that

require service.