MARSH SOUND DESIGN A200S User manual

MARSH SOUND DESIGN
OPERATING MANUAL
AS200
Power amplifier

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The lightning flash with arrowhead, within an equilateral triangle, is intended to alert the user 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 people.
CAUTION:
To prevent the risk of electric shock, do not remove the cover (or back) . No user-serviceable parts inside.
Refer servicing to qualified service personnel.
The exclamation point within an equilateral triangle is intended to alert the user to the presence of important
operating and maintenance instructions in the literature accompanying the appliance
RISK OF ELECTRIC SHOCK
DO NOT OPEN
WARNING: TO PREVENT FIRE OR SHOCK HAZARD, DO NOT OPEN OR
EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.
Warning

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Before proceeding with the installation, please read the instructions carefully and completely. If you have
any problems, do not hesitate to contact your retailer or our Service Department.
1. All warnings on the unit and in the operating manual should be followed.
2. Operate the unit only from a power source of the appropriate voltage indicated on the rear panel.
3. Do not use a damaged or deformed power cord as it may cause electric shock. When removing the plug
from the wall outlet, be sure to remove by holding the plug attachment and not by pulling the cord.
4. This unit should not be used near water or in humid conditions.
5. Do not pour or spill liquids of any kind onto this unit.
6. Do not operate this product with any cover removed.
7. Before connecting or disconnecting any cables, always turn off your equipment and disconnect your
entire system from the AC mains.
8. Do not replace any fuse with a value or type other than that specified.
9. Do not overload the wall outlet or extension cord because this can result in a risk of fire or electric shock.
10. Do not push objects of any kind into this product through the openings e.g., ventilation slots, because
they may touch dangerous voltage points or short-out parts. This act could result in a fire or electric
shock.
11. Do not attempt to repair this product because opening or removing covers may expose you to dangerous
voltage or other hazards. If a problem occurs, contact your Marsh retailer.
12. Disconnect your entire system from the AC mains before cleaning.
13. Slots and openings in the cabinet are provided for ventilation and to ensure reliable operation of this
product and to protect it from overheating. These openings must not be blocked or covered.
14. The operating temperature ranges from +5 to +35 degrees C. Operating humidity ranges from 5% to
80%. Do not operate the unit when the temperature and/or humidity are outside of this range.
Important/Precautions

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Thank You for purchasing the MARSH SOUND DESIGN MSD-A200S.
MSD brings you extraordinary components that are true, above all, to the art of music.

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Table of Contents
Important/Precautions..............................................................................................2
Preface.....................................................................................................................6
Unpacking............................................................................................................8
Placement Considerations.........................................................................................9
Functions.................................................................................................................10
Connections............................................................................................................11
Internal Protections..................................................................................................12
Troubleshooting guide.............................................................................................13
Care & Maintenance...............................................................................................14
Warranty information................................................................................................15
Specifications..........................................................................................................16
Dimensions..............................................................................................................17

MSD's logo comes from an ancient Native American petroglyph pecked in
stone, high in the Sierra Nevada mountain range. Long ago, small, self-
sufficient groups of people moved about the mountains, hunting and
gathering, and celebrating rituals. Leaving behind little about themselves, except for
these rock figures and a few stone tools. The mark we found, created a thousand years
ago, could have been a sun sign, a map, or a symbol of focus and concentration-or yet
some mystery we cannot imagine today.

Preface
Just as a great performer spends years learning his or her instruments, so a master designer spends years
understanding the complexities of audio circuitry and the science of electronics.
The Marsh Sound Design team builds its products to the most exacting standards of design and construction, for
simplicity of use, long life and timeless performance. Your investment in a Marsh product means that you can
forget about the hardware and focus on years of enjoyment.
For more than 30 years, author, lecturer, engineer, and inventor, has shared the art of
perfecting audio circuits with other designers. Now, his goal is to bring you his accumulated experience in the
service of music.
The A200S gives out 120 watts per channel, for a total of 240 watts. The A200S is designed with a High End circuit
with very low-noise FETs. A balanced, complimentary differential input circuit makes the A200S even more
linear than other systems.
Complex? Yes, but elegant and effective. The output stage has two pairs of high current, paralleled, bi-polar
power transistors to meet the peak current demands of any speaker system. Dynamic transient sounds come
through with full impact and clarity. Servo-controlled, direct-coupled circuitry is used throughout the circuitry
for extremely high resolution sound.
Richard N. Marsh,
So - set your course for the music . . .and leave the rest to us.
The MSD-A200S

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Unpacking
WARNING:
.
PEOPLE WITH BACK PROBLEMS SHOULD NOT UNPACK THIS EQUIPMENT
WITHOUT ASSISTANCE
1. Carefully lift the unit out of the box.
2. Remove the foam packing material.
3. Set up the unit for use.
REMEMBER: Keep all the original packing in case it is necessary to return the unit for servicing.
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Placement Considerations
DO NOT INSTALL THE UNIT IN THE FOLLOWING LOCATION:
1. In a place subject to direct sunlight.
2. In a humid place.
3. In an extremely hot or cold place.
4. In a place subject to vibrations.
5. In a dusty place.
6. In a poorly ventilated place.

Functions
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1. POWER Pressing the POWER button once to turn the unit ON. Press the POWER button again
to turn the unit OFF.
2. LED indicator The LED on the front panel will appear BLUE when the unit is ON. The LED will not
be lit when the unit is switched OFF.
In case of a malfunction, the unit will go into protect mode. The LED will be off. See
more detail in the internal Protections section.
REMARK: The MSD-A200S can be linked with other MARSH SOUND DESIGN remote control preamplifiers to
utilize the remote on/off option of your preamplifier.
1
2
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HR
PPS S A
IGH ESOLUTION
USH- ULL OLID- TATE MPLIFIER
MSD- 200AS
Marsh Sound Design

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1. UNBALANCED INPUTS Receive signals from unbalanced preamplifier outputs.
2. BALANCED INPUTS Receive signals from balanced preamplifier outputs.
3. INPUT SELECTOR SWITCHES Select according to the type of inputs being used.
4. MAIN FUSE If there is a problem with the fuse, replace with a fuse of the same
type and rating.
5. POWER Connect the MSD-A200S to the outlet with the enclosed power
cord.
6. REMOTE IN This is a digitally controlled input designed to receive +12VDC
from others MARSH SOUND DESIGN preamplifiers with
remote Turn on capability or from other equipment e.g. power
control center. With this function, the MSD-A200S can be
powered ON/OFF synchronized with that equipment.
7. SPEAKERS Output signals to speakers. The MSD-A200s has 2 output
connections for each channel. It is designed to be used with a pair
of bi-wire speakers.
IMPORTANT: Operate the unit only from the power source of the appropriate voltage indicated on rear
panel.
Connections
3
SPEAKERS SPEAKERS
BI-WIRED BI-WIRED
A A
B B
RIGHT LEFT
LEFTRIGHT
BALANCED BALANCED
UNBALANCED UNBALANCED
INPUTS
REMOTE IN
8A SLO-BLO
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MODEL: MSD- 200AS
POWER AMPLIFIER
SERIAL
NUMBER
POWER CONSUMPTION : 600 W MAX
60 HzAC 120 Volts
PUSH PUSH
TO PREVENT FIRE AND SHOCK HAZARD, DO NOT
EXPOSE THIS DEVICE TO RAIN OR MOISTURE.
- DO NOT OPERATE WITH COVERS REMOVED -
CAUTION FOR CONTINUED PROTECTION
AGAINST FIRE HAZARD, REPLACE ONLY
WITH SAME TYPE AND RATING FUSE.
RISK OF ELECTRIC SHOCK
DO NOT OPEN
AVIS : RISQUE DE CHOC ELECTRIQUE-NE PAS OUVRIR
WARNING
CAUTION
F
U
S
E
1 1
5
2
2
34
6
7 7
77

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1. OVER-CURRENT PROTECTION The MSD-A200S will go into protect mode and cut off the
main power supply to protect the amplifier and speakers.
This usually happens when the speaker terminals or wires
are accidentally shorted together.
2. DC-FAULT PROTECTION The MSD-A200S will go into protect mode when it detects
DC voltage at the speaker output. This is caused by a DC
voltage leak from the pre-amplifier outputs or by an
internal fault that gives a DC voltage leak at the speaker
output.
When in the above mentioned protect mode, the unit will shut down to prevent damage to itself or the
speakers. If this occurs, wait about 3 seconds for the unit to reset and turn itself on again.
If protect mode continues, turn the unit off and contact our service department.
3. OVERHEAT PROTECTION If the temperature of the output transistors exceed 76
degrees C, the MSD-A200S will shut itself down. It will
not restart automatically. Wait 5 to 10 minutes to let the
unit cool down, and then press the POWER button to turn
it back on.
Internal Protections

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Troubleshooting Guide
If the unit does not function properly, please check the list below and follow the instructions.
If the problem still occurs, please contact our service department.
PROBLEM
1. Unit does not turn on.
The LED is not lit.
2. No sound.
3. No sound from one speaker.
4. Low bass sound.
SOLUTION
Confirm that the power cord is plugged in
properly.
Check If the fuse is still good.
Check the speaker cable connection.
Check the interconnect cable connection.
Check the setting of the input selector
switches at the rear panel. They must be set
according to the type of input (Balanced or
Unbalanced) being used.
Check the speaker or interconnect cable
connection.
Check the BALANCE control on the
preamplifier, make sure that it is in the
middle position.
Check the speaker cables for correct phase
connection.

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Use a soft, dry cloth to remove dust from the cabinet. For stubborn dirt, soak the cloth in a weak detergent
solution. Be sure to wring the cloth well before wiping the unit. Use a dry cloth to wipe it dry. Do not use any
volatile agents such as benzine or thinner. They may damage the surface of the cabinet.
CAUTION: DISCONNECT YOUR ENTIRE SYSTEM FROM THE AC MAINS BEFORE
CLEANING. NEVER APPLY LIQUID CLEANSERS DIRECTLY TO THE UNIT. IT MAY RESULT
IN DAMAGE TO THE ELECTRONIC COMPONENTS WITHIN THE UNIT.
Care & Maintenance

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1. A MARSH SOUND DESIGN warranty only applies to the original retail purchaser. The warranty
certifies that the product is free from defects in material and workmanship and authorizes free service
and/or parts exchange
at an authorized MARSH SOUND DESIGN Service center.
2. The warranty is subjected to the following conditions and limitations. The warranty is void if the
product has been used in a manner other than that specified within the operating manual, if the
product has been abused or misused, or if the product has been repaired by anyone other than an
authorized MASH SOUND DESIGN Service center.
3. The warranty does not apply to defects or failure caused by usage of unauthorized parts, improper
maintenance, fire, flood, lightning or other natural causes.
4. This warranty does not cover damage to the external parts, e.g. Front panel, knobs, casing, etc.
5.
for a period of TWO years from the date of purchase. Service must only be
done
A returned product must include a copy of the Warranty Certificate and the bill of sale and must be
sent in the original packaging.
6. The warranty does not extend to any incidental or consequential cost or damage to the purchaser
caused by a malfunction of the product.
Warranty information

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Maximum Power Output per Channel 120 W both channels driven continuously into 8 ohms
load at 1 kHz
190 W both channels driven continuously into 4 ohms load
at1 kHz
Frequency response, 20-20000 Hz +0/- 0.2 dB at 1W to 100 W output into 8 Ohms loads
-1 dB at 80 kHz
THD+ Noise at maximum output <0.02% from 20 Hz to 20 kHz into 8 Ohms loads
(<0.01% at 1 kHz.)
Input Sensitivity for 100 W at 8 Ohms load 1 Vrms for Unbalanced and Balanced Input mode
Input Impedance 56 kOhms Unbalanced, 4 kOhms Balanced input
Input Power AC 110-120 V 60 Hz
Power consumption 600 W Max.
Size 19" W x 5 3/4” H x 13”D
Weight Net 30 lbs (13.2 kgs), Shipping 34 lbs (15.2 kgs)
Specifications

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Dimensions A200S
117.0 mm.
4 5/8”
117.0 mm.
4 5/8”
15.0 mm.
3/4”
329.0 mm.
13.0”
482.0 mm.
19.0”
450.0 mm.
17 3/4”
482.0 mm.
19.0”
145.0 mm.
5 3/4”
123.0 mm.
4 7/8”
123.0 mm.
4 7/8”
Marsh
HR
PPS S A
IGH ESOLUTION
USH- ULL OLID- TATE MPLIFIER
MSD- 200AS
Marsh Sound Design
SPEAKERS SPEAKERS
BI-WIRED BI-WIRED
A A
B B
RIGHT LEFT
LEFTRIGHT
BALANCED BALANCED
UNBALANCED UNBALANCED
INPUTS
REMOTE IN
8A SLO-BLO
Marsh
MODEL: MSD- 200AS
POWER AMPLIFIER
SERIAL
NUMBER
POWER CONSUMPTION : 600 W MAX
60 HzAC 120 Volts
PUSH PUSH
TO PREVENT FIRE AND SHOCK HAZARD, DO NOT
EXPOSE THIS DEVICE TO RAIN OR MOISTURE.
- DO NOT OPERATE WITH COVERS REMOVED -
CAUTION FOR CONTINUED PROTECTION
AGAINST FIRE HAZARD, REPLACE ONLY
WITH SAME TYPE AND RATING FUSE.
RISK OF ELECTRIC SHOCK
DO NOT OPEN
AVIS : RISQUE DE CHOC ELECTRIQUE-NE PAS OUVRIR
WARNING
CAUTION
F
U
S
E

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Notes

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Notes

MARSH SOUND DESIGN
Email: [email protected]
www.marshsounddesign.com
Tel: [phone] Fax: [phone]
62 El Camino Drive, Corte Madera, CA 94925
Marsh