Carver Group MA202R Stereo Multi-Purpose Amplifier User Manual
Carver Holdings Group Ltd. Stereo Multi-Purpose Amplifier Users Manual
User manual
www.car ver-usa.com
MA202R
Stereo Multi-Purpose Amplifier
USER'S GUIDE
TABLE OF CONTENTS
SAFETY PRECAUTIONS Page1
THANK YOU FOR YOUR MA202R PURCHASE Page3
SPECIFICATIONS Page4
FRONT PANEL LAYOUT Page5
REAR PANEL LAYOUT Page7
MASTER VOLUME Page5
BLUETOOTH Page6
ONLY ONE BLUETOOTH DEVICE CAN BE PAIRED TO THE MA202R AT A TIME Page6
POWER ON/ POWER STANDBY Page5
BLUETOOTH ANTENNA Page7
FLAT/ LOW PASS SWITCH Page7
LOW PASS FREQ DIAL Page8
POWER ON/OFF Page7
MONO/STEREO SWITCH Page8
AUX1 INPUT (RCA) Page8
IMPORTANT NOTE Page9
ON/AUTO SWITCH Page8
AUX 1 OUTPUT (RCA) Page9
SPEAKER OUTPUT TERMINALS BRIDGE MONO Page9
AC POWER INLET Page9
SPEAKER OUTPUT TERMINALS Page9
BACK PANEL FAN PORT Page9
TABLE OF CONTENTS
TROUBLESHOOTING GUIDE Page12
No Sound (from one or more speakers connected to the MA202R) Page12
The amplifier shuts down unexpectedly Page12
Poor Bass Performance From Full Range Speakers connected to the MA202R Page12
Turn-on and turn-off thumps Page12
“Hum”Noises in the Speakers Page13
Other Causes of Noise Page13
CONNECTION DIAGRAMS Page10
Stereo Connection Page10
Bridged Dual Mono Connection Page11
Daisy Chaining MA202R Amplifiers Page11
Bridged Subwoofer Connection Page10
1
Imortant Safety Instructions!
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 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 wider 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, partic
ularly 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 a 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 req
uired 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 ex
posed to rain or moisture, does not operate normally, or the been
dropped.
15. DO NOT expose this apparatus to dripping or splashing and ensure
that no objects filled with liquids, such as vases, are placed on the
apparatus.
16. To completely disconnect this apparatus from the AC Mains, disc
onnect the power supply cord plug from the AC receptacle.
17. The mains plug of the power supply cord shall remain readily
operable.
Protective earthing terminal. The apparatus should be connect
ed to a mains socket outlet with a protective earthing connection.
Voltage selector: Used to adjust the input rating (120 Vac/60 Hz a
nd 230 Vac/50 Hz), please just insert the mains power plug into t
he socket-outlet with voltage within the setting of the selector. T
he current ratings of mains fuse links are different for different in
put rating (see marking for details), and the fitted mains fuse link
was just related to the input rating as setting of the selector during
factory assembly line work, please ask a qualified personnel to he
lp you replace the mains fuse link before you adjust the voltage
selector.
The exclamation point, within an equilateral triangle, is
intended to alert the user to the presence of important
operating and maintenance (servicing) instructions in the
literature accompanying the product.
The lightning flash with arrowhead symbol within an eq
uilateral triangle. is intended to alert the user to the pre
sence of uninsulated “dangerous voltage” within the pro
duct’s enclosure that may be of sufficient magnitude to
constitute a risk of electrical shock to persons.
WARNING: To reduce the risk of fire or electrical shock, do not expose
this apparatus to rain or moisture.
WARNING: No naked flame sources-such as candles-should be placed
on the product.
Place the equipment near a main power supply outlet and make sure
that you can easily access the power breaker switch.
WARNING: This product is intended to be operated ONLY from the AC
Voltages listed on the back panel or included power supply of the pro
duct, Operation from other voltages other than those indicated may
cause irreversible damage to the product and void the products war
ranty. The use of AC Plug Adapters is cautioned because it can allow the
product to be plugged into voltages in which the product was not des
igned to operate, If the product is equipped with a detachable power
cord, use only the type provided with your product or by your local di
stributor and or retailer. If you are unsure of the correct operational
voltage, please contact your local distributor and/or retailer.
EU COMPLIANCE INFORMATION:
Eligible to bear the CE mark, Conforms to European Union Low Voltage
Directive 2006/95/EC; Conforms to European Union EMC Directive
2004/108/EC, Conforms to Eco- Design Directive 2009/125/EC, Conf
oms to REACH Directive 2006/121/EC.
WEEE NOTICE
Note: This mark applies only to countries within the European Union
(EU) and Norway
This appliance is labeled in accordance with European
Directive 2002/96/EC concerning waste electrical and
electronic equipment (WEEE). This label indicates that
this product should not be disposed of with household
waste. It should be de posited at an appropriate facil
ity to enable recovery and recycling.
FCC AND CANADA EMC COMPLIANCE INFORMATION:
This device complies with part 15 of the FCC Rules. Operation is subject
to the following two conditions:
(1) This device may not cause harmful interference, and (2) this device
must accept any interference received, including interference that may
cause undesired operation.
NOTE: This equipment has been tested and found to comply with the
limits for a Class B digital device, pursuant to part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against ha
rmful interference in a residential installation. This equipment gener
ates, uses and can radiate radio frequency energy and, if not installed
and used in accordance with the instructions, may cause harmful inte
rference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment
does cause harmful interference to radio or television reception,which
can be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of the
following measures:
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Connect the equipment into an outlet on a circuit different from that
to which the receiver is connected.
Consult the dealer or an experienced radio/TV technician for help.
Approved under the verification provision of FCC Part 15 as a Class B
Digital Device.
Caution: Changes or modifications not expressly approved by the ma
nufacturer could void the user ’s authority to operate this device.
Caution: To comply with the limits of the Class B digital device, pursu
ant to Part 15 of the FCC Rules, this device is to comply with Class B li
mits. All peripherals must be shielded and grounded. Operation with
non- certified peripherals or non- shielded cables my result in interfe
rence to radio or reception.
2
THANK YOU FOR YOUR PURCHASE OF THE CARVER MA202R
All Carver products are designed using the highest quality components and cutting edge
technology providing years of enjoyment from your Carver product.
The MA202R is easy to operate and integrate into your system
MA202R
MA202R
. This owner's reference manual
contains important information on the placement, installation, and operation of the .
Please read this information carefully. A thorough understanding of these details will help ensure
satisfactory operation and long life for your and related system components.
Your MA202R includes the amplifier, Bluetooth antenna, power cord and operation manual.
If your MA202R is missing any components listed please contact Carver at www.carver-usa.com.
Always place your MA202R in a well-ventilated area. Never place the amplifier close to or on top
of a heat source like another amplifier or component that produces heat. Always leave at least 3
inches clearance on top of the amplifier and never block the vent holes on top of the chassis. The
MA202R can be placed on a rack shelf side by side with other MA202R units to complete your
system however you must leave space above the amplifier for ventilation. Place your MA202R
away from any sources of moisture or liquids. Never use this amplifier outdoors where rain or
moisture is present.
When using the on-board Bluetooth feature included in your MA202R it's best to keep the Bluetooth
antenna line-of-sight to the Bluetooth transmitter you are using. Smartphones should be within
25 feet of the MA202R for best results when using Bluetooth. Positioning the amplifier in a
concealed location can limit the range of the Bluetooth reception. If your Bluetooth reception
is weak, move the amplifier to a more central location.
3
Unpacking:
Placement:
Important Note:
www.carver-usa.com
SPECIFICATIONS
4
FRONT PANEL LAYOUT
5
L EV EL
M A2 0 2 R
POWER
1
3
2
POWER ON/POWER STANDBY:
Turn the master volume control clockwise to increase the volume level and counter clockwise
to decrease the volume level.
MASTER VOLUME:
The power LED will light green when the back panel power switch is switched ON and the power
LED will light red when the MA202R is in standby mode. Standby mode is a power saving feature
that keeps the MA202R ready for use while conserving energy when the unit is not in use. The
of the power LED depends on the back panel Auto/On power mode setting. Read more
on this feature later in the Power Mode Switch section of the manual.
status
1
2
BLUETOOTH:
The MA202R is equipped with an on-board Bluetooth receiver/player which converts the unit
into a wireless receiver/amplifier. This feature provides wireless connection from any Bluetooth
enabled device like smartphones, computers and MP3 devices with Bluetooth capability.
Wireless connection to the MA202R is simple and can be completed by following these steps.
-Press the MA202R back panel main power switch ON.
-Power ON your smartphone or Bluetooth enabled device.
-Make sure that Bluetooth is enabled on your smartphone or Bluetooth device.
-The MA202R will automatically search for Bluetooth devices for connection.
CARVER MA202R will appear in your list of devices automatically.
Press the PAIR feature on your smartphone or Bluetooth device.
Once a successful connection is established your smartphone or Bluetooth device will show
“connected” and the Bluetooth button on the front panel of the MA202R will light.
Now play music from your smartphone or Bluetooth device.
NOTE:
If another source is connected to the back panel RCA input jacks both the Bluetooth signal and
the RCA input will play simultaneously. When using Bluetooth always turn the source connected
to the RCA inputs OFF to avoid mixing both the Bluetooth and RCA sources together.
Only one Bluetooth device can be paired to MA202R at a time.
To connect another device to the MA202R un-pair the currently connected device and repeat
the pairing procedure listed above.
3
6
REAR PANEL LAYOUT
7
1
BLUETOOTH ANTENNA:
Position the Bluetooth antenna in an upright position and keep a clear line of sight to the area
where Bluetooth transmitting devices will be used.
2
POWER ON/OFF:
The MA202R can be powered ON continuously using the back panel power switch. The MA202R
provides a power saving standby mode which keeps the amplifier in a low power “sleep”state
when no input signal is present for more than 4 minutes. The front panel power LED will glow
RED in standby mode and GREEN in normal mode. When the power switch is turned ON initiall
y the power LED will glow green. If the MA202R will not be in use for long periods of time al
switch the back panel power switch OFF.
ways
3
FLAT / LOW PASS SWITCH:
Keep the switch in the FLAT position for normal stereo operation. The FLAT position will broadcast
all input signals without equalization or coloration. This is the normal operating mode of the
MA202R. The LOW PASS switch will engage the internal low pass filters and the LOW PASS FREQ
dial will activate.LOW PASS is a filter that will remove all frequencies above the setting
3
5
4
6
7
8
1
10
2
11
12
9
L
OUTPUT
R
of the LOW PASS FREQ dial and pass all frequencies below the setting of the LOW PASS FREQ
dial. The LOW PASS switch and dial are used when the MA202R is configured as a subwoofer
amplifier. Subwoofers typically reproduce frequencies between 40Hz and 180Hz. It is not
desirable for subwoofers to reproduce frequencies above 180Hz because subwoofers are specially
design to reproduce bass frequencies.
4LOW PASS FREQ DIAL:
The LOW PASS FREQ dial will only be activated if the FLAT / LOW PASS switch is in the UP/ON
position. Use the dial and switch to power subwoofer speakers. The precise crossover frequency
for your subwoofer can be achieved by adjusting the LOW PASS FREQ dial. It is common practice
to keep your subwoofer crossover frequency below the usable frequency range of your main
left/right speakers. For Example: If the rated frequency response of your main left/right speakers
is 100Hz -20kHz set the LOW PASS FREQ dial to 100Hz. With this configuration your main left/right
speakers will reproduce frequencies from 100Hz-20kHz and your subwoofer will reproduce the
frequencies from 100Hz to 40Hz. This setup will provide a full range listening experience. Each
speaker performs differently, use this as a guide and experiment with theLOW PASSFREQ dial to
achieve the best results with your system.
5MONO/STEREO SWITCH:
Keep this switch in the STEREO position for normal stereo operation.The minimum speaker
Impedance that can be used in stereo mode is 4ohms.The MONO switch can be used to combine
the left and right amplifiers to one single higher power amplifier.This is called BRIDGE MONO
MODE. Use the BRIDGE MONO MODE for powering a single speaker or speaker driver or subwoofer.
The minimum speaker impedance in BRIDGE MONO MODE is 8ohms.
Never connect speakers or multiple speakers to the MA202R with impedances lower than
4ohms in stereo mode and 8 ohms in BRIDGE MONO MODE. Low impedances can damage the
MA202R and potentially damage your speakers. If you are unsure how to connect your MA202R
contact a Carver technician at www.carver-usa.com before making your connections.
6ON/AUTO SWITCH:
7
The ON/AUTO switch provides two power-on modes. With this switch in the ON position the
MA202R will be fully powered-on constantly. Use this mode when you want to disengage the
power saving feature or when the MA202R is used continuously for long periods of time. With
this switch in the AUTO position the MA202R will operate normally and will enter the power
saving standby mode automatically if the input signal is not present for more than 4 minutes.
This is the normal operating mode for the MA202R. The MA202R will save energy when not in
use and will power ON automatically when an audio source is present at the AUX1 input or
Bluetooth input. In this mode the MA202R is ready when you are and conserving energy when
notin use.
AUX1 INPUT (RCA):
Connect your wired music source here using RCA jacks. The AUX 1INPUT will accept line level
sources from CD/Blue Ray players, computers, MP3 players radio tuners, pre-amplifiers, mixers
and practically any line level audio source.
8
IMPORTNT NOTE:
The AUX 1 INPUT jacks and the Bluetooth input are wired in parallel. If both the AUX 1 INPUT
and the Bluetooth input are broadcasting at the same time both sources will be heard
simultaneously. When using the AUX 1 INPUT always turn your Bluetooth device OFF. When
using your Bluetooth device always turn your AUX 1 INPUT source off.
AUX 1 OUTPUT (RCA):
8
The AUX 1 OUTPUT is a line level variable pre-amp output which can be used to connect the line
level output of the MA202R to other devices such as auxiliary amplifiers, mixers or more commonly
powered subwoofers like the Carver BAS8. This is the most common connection for the AUX 1
OUTPUT. This output is variable which means when the front panel master volume control is
adjusted up/down the level of the AUX 1 OUTPUT will also change or “track”. This is very useful
when connecting the MA202R to a powered subwoofer which will have its own volume control.
Once the desired subwoofer volume is achieved the MA202R will raise or lower the subwoofer
volume in conjunction with the main speakers connected to the MA202R speaker outputs.
SPEAKER OUTPUT TERMINALS:
9
The speaker output terminals are 5 way binding posts that will accept speaker wire gauges from
18awg to 12awg with direct wire-in, spade lug or banana jack connections. Turn the terminal
counter clockwise to unscrew the protector and expose the terminal for direct wire-in. Turn the
terminal clockwise to tighten the protector over the wire and never over tighten. Connect your
(min 4ohm) left channel speaker to the “L” terminal keeping the + positive wire to the RED
connector and the – negative wire to the BLACK terminal. Repeat these connections for your
(min 4ohm) right channel speaker. Pay close attention to the polarity of the wires. Always keep
the + to RED and the – to BLACK. Crossing any one of these connections can create reverse polarity
in one speaker which will destroy the sound quality of your stereo system.
IMPORTANT NOTE: Never cross positive and negative wires. This will short the amplifier
potentially causing damage to the MA202R.
SPEAKER OUTPUT TERMINALS BRIDGE MONO:
10
In bridge mono mode connect one (min 8ohm) speaker to the following terminals, + positive
to the LEFT RED terminal and the – negative to the RIGHT BLACK terminal. Leave the other two
terminals unconnected.
AC POWER INLET:
11
Connect the supplied AC power cable to the AC inlet jack and push into place making sure that
the AC cable is fully inserted. If the MA202R will be left unused for an extended period of time
we recommend that the power cord be disconnected from the wall outlet. This will insure that
power surges, power brownouts and lightning strikes will not damage the MA202R.
BACK PANEL FAN PORT:
12
The MA202R back panel fan port should never be blocked. Always provide a minimum of 3 inches
of clearance from the back of the unit to any wall or solid surface. We recommend that you
vacuum the vent periodically to remove dust and contaminates that can clog the fan and the
fan port.
9
FCC I D:2AB K7MA2 02R
IC ID :1162 9A-MA 202R
CONNECTION DIAGRAMS
Stereo Connection
This diagram shows the MA202R connected to 2 speakers in a stereo configuration. The crossover
switch is in the FLAT position. Speakers can be 4-8 Ohms.
This configuration delivers 75 watts into
each 4 Ohm speaker. You can also use 8
Ohm speakers in this configuration
This connection diagram shows
a typical use of the MA202R in
a stereo configuration driving
one left channel and one right
channel speaker. This setup
is ideal for a second zone or
whenever the main speaker in
the room are assembled in a 2
channel configuration
Bridged Subwoofer Connection
This diagram shows the MA202R connected to 1 subwoofer in a bridged configuration. The LEFT
input is the mono input for the bridged configuration and will come from your receiver or
preamplifier’s subwoofer output. The crossover switch is in the LOWPASS position. Crossover
frequency should begin around 100Hz and be fine tuned once the system is playing as it depends
on the frequency response of the other main speakers in your system. The subwoofer should be
no lessthan 8 Ohms.
This connection diagram shows
a typical use of the MA202R in a
bridged configuration driving
a single subwoofer. This
setup is ideal for non powered
subwoofers or the woofer
portion of a multi-element
speaker that has bi-amp
capabilities
This configuration delivers 150 watts into
a single 8 Ohm speaker. You MUST use
a speaker with a minimum of 8 Ohms
nominal impedance for the bridged
configuration!
10
12 0 V ~ T5 A L 6 0 Hz 350 W
23 0 V~ T2 . 5 AL 5 0H z 350 W
00
12 0 V ~ T5 A L 6 0 Hz 350 W
23 0 V~ T2 . 5 AL 5 0H z 350 W
00
L
OUTPUT
R
L
OUTPUT
R
FCC I D:2AB K7MA2 02R
IC ID :1162 9A-MA 202R
FCC I D:2AB K7MA2 02R
IC ID :1162 9A-MA 202R
FCC I D:2AB K7MA2 02R
IC ID :1162 9A-MA 202R
FCC I D:2AB K7MA2 02R
IC ID :1162 9A-MA 202R
L
OUTPUT
R
L
OUTPUT
R
L
OUTPUT
R
L
OUTPUT
R
12 0 V ~ T5 AL 6 0 Hz 350 W
23 0 V~ T2 . 5 AL 5 0H z 350 W
00
Bridged Dual Mono Connection
This diagram shows two MA202R amplifiers connected to 2 full range speakers, each in a bridged
configuration. The crossover switch is in the FLAT position. The RCA inputs are split so that each
channel is fed into the LEFT RCA input at the amplifier. The LEFT input is the mono input for the
bridged configuration. The speakers should be no less than 8 Ohms. This configuration allows
the greatest channel separation and increases the individual power for each speaker.
This configuration delivers
150 watts into each 8 Ohm
speaker. You MUST use a
speaker with a minimum of
8 Ohms nominal impedance
for the bridged configuration!
This connection diagram
shows a typical use of two
MA202R’s in a “dual mono”
stereo configuration with each
one driving a single full range
speaker. This setup is ideal
for a maximizing power to a
speaker that requires 150 watts
instead of 75 watts. You would
gain roughly 3dB in output over
a single amplifier configuration
using this method.
This diagram shows two MA202R amplifiers in a “Daisy Chain” configuration. Using the LINE OUT
RCA jacks, you can pass signal through the MA202R on to other MA202R amplifiers. Based on how
you want the amplifiers after the first one is configured, you can select stereo or mono operation.
It’s advised to use the stereo amplifiers first in the signal chain and then break off to the mono
configurations when using multiple MA202R amplifiers.
Daisy Chained MA202R Amplifiers
This connection diagram
shows a typical use of two MA202R’s
running an entire full bandwidth,
multi-speaker system. This
setup is ideal for a using small
“book shelf ” style main speakers
and a separate discrete
subwoofer to reinforce the low
frequency content.
This configuration delivers
75 watts into each 4 Ohm
stereo speaker (on the left).
You can also use 8 Ohm
speakers in this
configuration
This configuration also
delivers 150 watts the 8 Ohm
subwoofer. You MUST use a
speaker with a minimum of
8 Ohm nominal impedance
for the bridged configuration!
11
12 0 V ~ T5 AL 6 0 Hz 350 W
23 0 V~ T2 . 5 AL 5 0H z 350 W
00
12 0 V ~ T5 AL 6 0 Hz 350 W
23 0 V~ T2 . 5 AL 5 0H z 350 W
00
FCC I D:2AB K7MA2 02R
IC ID :1162 9A-MA 202R
FCC I D:2AB K7MA2 02R
IC ID :1162 9A-MA 202R
TROUBLESHOOTING GUIDE
The CARVER MA202R is designed and built to provide years of trouble-free performance.
Most problems that occur can usually be solved by checking your setup or making sure that the
audio and video components connected to the amplifier are on and fully operational.
, contact your CARVER Dealer for help.
If the
problem persists
No Sound (from one or more speakers connected to the MA202R)
Speaker cables may have come undone. Turn off your system and check the cables, and tighten
the amplifier and speaker binding posts.
Damaged audio cable.
The preamplifier volume level is low for the channels concerned. Recheck the preamplifier
calibration procedure.
A preamplifier Mute switch may be on, or an external processor loop or a tape monitor loop is
engaged.
Check that your preamplifier or source is running the correct surround sound mode. Maybe it is
set for 2-channel stereo when you were expecting 5.1 surround sound.
Check in case any missing channels have been turned off in a preamplifier setup menu. For
example, the center amplifier channel will not receive a signal if the preamplifier has been set to
“Phantom”
The AUTO/ON switch on the MA202R might be in the ON position but the power switch is off.
Check the power switch.
A fuse within the unit may have blown.
The level on the MA202R is turned down.
The amplifier shuts down unexpectedly
Check that the positive and negative speaker wires are not shorted together.
Make sure that no speakers are shorted internally. lf you have an ohm-meter, disconnect the
speaker wires and measure the resistance between the speaker’s positive and negative terminals.
lf the reading is less than 4 ohms, you may be using speakers with too low a nominal impedance
OR they could be electrically shorted. Measure all speakers and check their impedance
specifications.
If you have connected speakers in parallel, the overall impedance may be too low. It is
recommended that you rearrange the speakers in a series wiring configuration to increase the
overall impedance, thus taking some of the load off the amplifier.
Make sure that the amplifier has good ventilation and is not overheating
Poor Bass Performance From Full Range Speakers connected to the MA202R
Make sure that your preamp does not have the bass (tone control) level turned down.
Many surround preamplifiers have controls which can direct all the bass to subwoofers or let your
main speakers play the full range. Make sure that the preamplifier has been correctly set. lf you
are not using a subwoofer, set the speaker options to “Large” where possible.
Check that the speaker wires have been connected correctly. Make sure that the positive of each
speaker connects to a positive output of the MA202 amplifier, and the negative of each speaker
connects to a negative output of the MA202 amplifier. lf one speaker is wired incorrectly, then
it will be “out of phase” with the others resulting in poor bass performance.
Turn-on and turn-off thumps
Plug the amplifier into an un-switched AC outlet, and use the AUTO position of the turn on swit
ch at the back of the amplifier. This will allow the amplifier to turn on and off silently.
12
“Hum” Noises in the Speakers
This problem is more than likely caused by a “ground loop” in your system, rather than a fault in
the MA202R. Follow these steps to isolate the main cause of the hum, there may even be more
than one. Remember to turn off all components in your system, including the MA202R, before
disconnecting or connecting any cables.
Ground loop isolators for audio lines and video devices are available from you CARVER Dealer.
Although this is not always an ideal solution, the grounding differences between certain home
entertainment components sometimes require ground loop isolators. Ths is the exception rather
than the rule.
Other Probable Causes of Noise
Speaker noise may also be caused by interference or noise on your AC line. Make sure there are
no large appliances sharing the line, or halogen lamps or light-dimming Triac devices.
If you have very high efficiency speakers, these may tend to reveal noises which other speakers
do not.
Remember to turn off all components in your system, including the amplifier, before disconnecting
or connecting any cables during troubleshooting.
Try to have all of your equipment on the same electrical outlet or circuit. Group all the low power
components (preamp, CD player, DVD etc.) on a single outlet or power strip. This is provided that
the overall current draw from your equipment does not exceed the rating of the outlet or breaker.
Disconnect all cables which come from outside the room, and check if the hum goes away. This
includes such connections as cable TV, satellite TV, or roof top antennas. Make sure that they are
disconnected where they first enter the room, so they are making no connection to the preamplifier
or the TV, or any other component. lf the hum is caused by the cable TV line, then you will need
a “ground loop isolator.” This is an inexpensive device fitted in line with the coaxial cable feed.
Contact your cable company or your CARVER Dealer for assistance.
Disconnect all connections from the preamplifier to your TV, VCR or DVD.
As a test, disconnect any other component which has a grounded power cord. Never remove the
ground pin from any power cords (if present). This is very dangerous.
If the hum persists, disconnect all the source components one at a time from the back of the
preamplifier, until you identify the problem.
Try moving the speaker cables away from any power cords. Try just one speaker, connecting it to
each amplifier channel and see if one channel is bad.
Check that the interconnect cables to the amplifier do not have any broken connections. The best
way to do this is to substitute a known good connection for the suspect connection. lf you reverse
the cables and the problem goes away, the cable may be damaged or broken. This is possible even
if you can’t physically see the break as the strain for pulling on audio cables can sometimes break
the wire internally.
Try connecting your system to another AC socket on a separate line.
If the hum is heard from within the MA202R and not through the speakers, this may also be caused
by interference on the AC or DC lines. The power transformers may turn this interference into
an audible noise. Internal hum can be made worse by a shelf or cabinet resonating, so try moving
the MA202R to another shelf.
Try moving your components further away from the TV, especially if you ever notice the screen
has changed color in the area closest to the component.
13
C ARVER HOLDINGS GROUP LTD.
www.ca r ve r- us a. co m
MA202R / 2014.2 / V1.1