Monoprice CasaTunes CT-250A User manual

CasaTunes CT-250A
2 x 50W Stereo Amplifier
User's Manual

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CONTENTS
SAFETY WARNINGS AND GUIDELINES ................................................................ 3
INTRODUCTION ......................................................................................................... 4
FEATURES .................................................................................................................. 4
PACKAGE CONTENTS .............................................................................................. 6
PRODUCT OVERVIEW .............................................................................................. 7
Front Panel .............................................................................................................. 7
Rear Panel ............................................................................................................... 7
THERMAL PROTECTION .......................................................................................... 8
SHORT CIRCUIT PROTECTION ............................................................................... 9
MOUNTING OPTIONS ............................................................................................. 10
Stand-Alone Setup ................................................................................................ 10
Single Rack-Mount Setup ..................................................................................... 10
Dual Rack-Mount Setup ........................................................................................ 12
STEREO INSTALLATION ......................................................................................... 12
MONO BRIDGED INSTALLATION .......................................................................... 16
SPECIFICATIONS ..................................................................................................... 19
REGULATORY COMPLIANCE ................................................................................ 20
Notice for FCC ...................................................................................................... 20
Notice for Industry Canada .................................................................................. 20

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SAFETY WARNINGS AND GUIDELINES
Please read this entire manual before using this device, paying extra attention
to these safety warnings and guidelines. Please keep this manual in a safe
place for future reference.
• This device is intended for indoor use only.
• Do not expose this device to water or moisture of any kind. Do not place
drinks or other containers with moisture on or near the device. If
moisture does get in or on the device, immediately unplug it from the
power outlet and allow it to fully dry before reapplying power.
• Do not touch the device, the power cord, or any other connected cables
with wet hands.
• This device uses a grounded power cord and requires a ground
connection for safe operation. Ensure that the power source has a proper
ground connection. Do not modify the plug or use a "cheater" plug to
bypass the ground connection.
• Do not expose this device to excessively high temperatures. Do not
place it in, on, or near heat sources, such as a fireplace, stove, radiator,
etc. Do not leave it in direct sunlight.
• This device ventilates excessive heat through the slots and openings in
the case. Do not block or cover these openings. Ensure that the device
is in an open area where it can get sufficient airflow to keep from
overheating.
• Prior to operation, check the unit and power cord for physical damage.
Do not use if physical damage has occurred.
• Take care to prevent damage to the power cord. Do not allow it to
become crimped, pinched, walked on, or become tangled with other
cords. Ensure that the power cord does not present a tripping hazard.

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• Never unplug the unit by pulling on the power cord. Always grasp the
connector head or adapter body.
• Ensure that power is turned off and disconnected before making any
electrical connections.
• Clean using a soft, dry cloth only. Do not use chemical cleaners,
solvents, or detergents. For stubborn deposits, moisten the cloth with
warm water.
• This device has no user serviceable parts. Do not attempt to open,
service, or modify this device.
INTRODUCTION
Thank you for purchasing the CasaTunes CT-250A Amplifier. This 2-channel
class D power amplifier features a stereo speaker output, with support for 4-
ohm and 8-ohm speakers. It can deliver 50 watts per channel into 8-ohm loads
or 65 watts per channel into 4-ohm loads. Additionally, the output can be
bridged to provide 120 watts to a single 8-ohm speaker. It includes a buffered
loop line output of the original signal for driving another power amplifier in
distributed whole house audio systems. The amp can be configured for always
on, signal detection, or triggered power on status. It also includes a 12-volt
trigger output for controlling other devices.
FEATURES
• Class-D amplifier providing 50 watts/channel (RMS) into 8 ohm loads or
65 watts/channel into 4-ohm loads
• Bridgeable output provides 120 watts into a single 8-ohm load
• 4-pole detachable speaker screw connector (Phoenix connector) with
support for up to 12 AWG speaker wire

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• 12-volt trigger input for power-on/off
• 12-volt trigger output for controlling other devices
• Buffered loop output of original signal for connecting additional amplifiers
• Rear panel volume gain adjustment
• Built-in thermal and short circuit protection circuits
• Includes rack-mount ears

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PACKAGE CONTENTS
Please take an inventory of the package contents to ensure you have all the
items listed below. If anything is missing or damaged, please contact
CasaTunes Customer Service for a replacement.
1x 100-watt stereo power amplifier
1x AC power cord (NEMA 5-15 to IEC 60320 C13)
1x Power cord anchor
1x Trigger cable
2x Short rack-mount ears
1x Long rack-mount ear
1x Bridge plate
6x Button head screws
4x Countersunk screws
4x Rubber feet
1x User's manual

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PRODUCT OVERVIEW
Front Panel
1. Power Switch: Turns the amplifier on and off.
2. Power LED: Illuminates amber on initial power-up, then glows either
green during normal operation or red when in standby mode.
Rear Panel
3. Line In: Stereo line-level analog RCA input jacks. When using bridged
mode, the mono input should be connected to the L input.
4. Line Out: Stereo, buffered, loop line output of the original signal for
connecting additional amplifiers.
5. Volume: Gain control to limit the maximum volume level.
6. Output Selection: Switch to configure the type of output. When in the
Bridged position, the amplifier can be bridged for more power into a

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single 8-ohm load. The 8-ohm and 4-ohm positions optimize the stereo
output for 8- or 4-ohm loads.
7. Power Selection: Switch to control the power-on behavior of the
amplifier. When in the On position, the amplifier is always on whenever
the Power Switch (1) is in the On position. When set to Auto, the
amplifier will automatically go into standby mode when no audio signal is
detected and will power on when an audio signal is detected. When set
to the Trigger position, the amplifier will power on or off whenever a 12-
volt trigger is applied to the Trigger In (8). When set to the Auto or
Trigger positions, the Power Switch (1) on the front panel should be left
in the On position.
8. Trigger: 3.5mm jacks for 12-volt Trigger In and Out. The Trigger In can
turn the amplifier on or off and the Trigger Out can be used to control
other devices.
9. Speaker: Removable Phoenix connector for attaching the speaker wires.
When connecting a single speaker in bridged mode, the negative lead
should be attached to L- and the positive lead to R+. It can accept
speaker wire up to 12 AWG.
10. AC IN: IEC 60320 C14 panel connector for attaching the included power
cord.
THERMAL PROTECTION
The amplifier monitors its temperature and will activate the thermal protection
circuit if the temperature exceeds a safe limit. This can occur if the amp has
been operated at high volumes for an extended period of time, if it has
inadequate ventilation, or if the speaker load is below the minimum impedance
of 4 ohms. The amp will shut down when the Thermal Protection circuit
engages. You must turn off the amp's power switch and wait until the amp
cools down, then power the amp back on.

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SHORT CIRCUIT PROTECTION
If the amplifier detects a short circuit on one or both speaker outputs, the
Power LED (2) will glow orange and output will be disabled. If this occurs, turn
off the amplifier and check the speakers and speaker wires for a short circuit.

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MOUNTING OPTIONS
This amplifier can be placed stand-alone on a flat surface, such as a table or
shelf, or can be installed into a standard 19" equipment rack, either by itself or
side-by-side with a second Unity power amp.
Stand-Alone Setup
To use the amplifier in a stand-alone installation, locate the included sheet with
four rubber feet. Peel each rubber foot from the sheet and attach them to the
bottom of the amp at each of the four corners. This will both protect your
mounting surface from scratches and will prevent any incidental noise from
vibration.
Single Rack-Mount Setup
Perform the following steps to install a single amplifier into a 19" equipment
rack.
1. Using three of the button head screws, attach one short rack-mount ear
to one side of the amplifier, with the flat side flush with the front panel.
2. Using the remaining three button head screws, attach the long rack-
mount ear to the other side of the amplifier, with the long flat side flush
with the front panel. It does not matter which side of the amp has the
short rack-mount ear and which side has the long one.
3. Using rack-mount screws (not included), secure the two rack-mount ears
to the rack mount.