Accustic Arts AMP I MK 2 User manual

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To our valued customer and music enthusiast,
With the purchase of your stereo power amplifier AMP I –MK 2 from ACCUSTIC ARTS®you have
opted for a product which incorporates the most modern technology to achieve excellent sound and
quality. To make sure that you have pleasure for as long as possible with your amplifier we kindly ask
you to thoroughly read this instruction manual through to the end.
We wish you many enjoyable hours of listening to music with your new unit.
SCHUNK AUDIO ENGINEERING –The home of ACCUSTIC ARTS®
1 AMP I –MK 2 highlights
Stereo power amplifier with high output performance, also suitable for less efficient, impedance
critical and low ohm loudspeaker systems up to 2 
8 selected MOS-FET output transistors of highest quality
Magnetically shielded and encapsulated 600 VA toroidal core transformer for high output
reserves; separate windings for right and left channel
Very good smoothing thanks to more than 80.000 µF power supply capacity; Premium quality
capacitors (“Made in Germany”)
Very high damping factor for perfect speaker control
Integrated protective circuit switches ascents off when clipping, HF oscillations or too high DC
offset occurs
Constant low operating temperature due to generously dimensioned heat sink integrated in
housing
Balanced input (XLR) and unbalanced input (RCA) –the inputs are switchable
ACCUSTIC ARTS®AMP I –MK 2 is “Handmade in Germany”

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CAUTION: WARNING:
TO REDUCE THE RISK OF FIRE OR
ELECTRIC SHOCK DO NOT EXPOSE
THIS PRODUCT TO RAIN OR MOISTURE
RISK OF ELECTRIC SHOCK
DO NOT OPEN
The lightning flash with arrowhead symbol, within an equilateral triangle,
is intended to alert the user to 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 the user
to the presence of important operating and maintenance (servicing) instructions
in the literature accompanying the appliance.
Marking by the “CE” symbol indicates compliance of this device with the EMC
(Electromagnetic Compatibility) and LVD (Low Voltage Directive) standards of
the European Community.
To guarantee a reliable function of this unit over the long-term we kindly ask you to thoroughly read
this instruction manual before connecting this unit and to observe the following instructions. This is
also necessary for your own safety when dealing with the unit.
2 Important safety instructions
Read these instructions.
Keep these instructions.
Follow all instructions.
Do not use this appliance near water.
Never use this appliance near hot surfaces.
Never use this appliance outside and always place it in a dry environment.
Check that your mains voltage corresponds to that stated on the appliance.
Never leave the appliance unsupervised when in use. Always keep electrical equipment out of the
reach of children.
Never pour or spill liquids directly onto this appliance.
Never operate this apparatus in an explosive atmosphere.
Do not put any vases or similar objects containing water or liquids on top of this appliance.
Unplug this appliance during lightning storms or when unused for long periods of time.

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Ensure that the appliance has sufficient air around it and avoid extreme temperature influences on
the unit, especially direct sunshine and high humidity.
Always disconnect the appliance from the mains power before carrying out any changes to the
cables or when cleaning the appliance.
Protect the mains cable from being walked on or pinched particularly at plugs, convenience
receptacles and the point where they exit from the appliance.
The mains cable (power cord) of this appliance is equipped with an equipment grounding
conductor. This equipment grounding conductor must never be disconnected or taped over. In
case any humming occurs please contact your authorized dealer.
From time to time check the mains cable and the appliance for damages. Take care that the mains
cable is not buckled or damaged by any house pets.
Never move the appliance by pulling the mains cable. Make sure the mains cable cannot get
caught in any way. Do not wind the mains cable around the appliance and do not bend it.
Never use accessories which are nor recommended by the manufacturer. They could constitute a
danger to the user and risk to damage the appliance.
Never operate the appliance with the housing open.
To clean the aluminium housing please only use a cloth moistened with water and some
detergent. Never use inflammable or chemically aggressive cleaning agents.
In the event of a defect, please never attempt to repair it yourself. Any tampering with the
appliance by an unauthorised person will make the warranty void. Please get in contact with your
authorized dealer.
Refer all servicing to qualified service personnel. Servicing is required when the appliance 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 appliance, the appliance has been exposed to rain or moisture,
does not operate normally or has been dropped.
Replace fuses only with original types having the same ampere value, the same voltage
endurance and the same time-lag. You can find the corresponding value in chapter 5.5 of this
instruction manual or on the backside of the apparatus.
Never bypass a fuse.
No user-serviceable parts inside.
IMPORTANT!
After switching the unit off please wait at least 30 seconds before
switching it on again.

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3 Unpacking
The weight of this appliance is approx. 20 kg / 44 lbs. Great care must be exercised when unpacking
the unit.
Carefully store the transportation packaging for the possibility of further use. If you have a claim on the
warranty, always use the original packaging for any necessary transportation. Transportation without
this packaging can lead to damage to the housing.
Please check, if the following items are included:
1 x AC mains cable (type depends on your country)
1 x replacement fuse (type depends on your mains voltage)
4 Positioning
Provided there is available space the power amplifier should, if possible be positioned as close as
possible to the loudspeakers since the loss within the loudspeaker cable is generally higher than with
interconnect cables. Therefore always use the shortest possible loudspeaker cable but of equal length
on the left and right side.
Due to these facts and due to its weight the power amplifier is usually set up in a position near to the
floor either between or near the loudspeakers. If you cannot set up the power amplifier in a free
position, then under no circumstances should the chimney effect of the heat sinks integrated under the
housing cover be restricted. Therefore leave a minimum of 5 cm distance at the sides and 10 cm
distance above the housing cover. Take care that the base of the power amplifier is always stable and
level.
IMPORTANT!
DANGER OF FIRE!!
Please never cover the ventilation slots. This could lead to overheating of
the power amplifier and cause serious damage.

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5 Installation
Fig. 1: Rear panel
1Mains inlet connector socket
2FUSE: Fuse holder for protection of unit
3POWER: Mains power switch
4.1 SPEAKER RIGHT: Right pair of loudspeaker output sockets
4.2 SPEAKER LEFT: Left pair of loudspeaker output sockets
4.3 Earth connection e.g. for shielded speaker cable
5.1 BALANCED: XLR input socket for preamplifier output signal
5.2 UNBALANCED: RCA input socket for preamplifier output signal
5.3 INPUT SELECTION: Input selection for audio inputs
5.1 Interconnect cables
The AMP I –MK 2 has balanced XLR input sockets 5.1 and unbalanced RCA input sockets 5.2. To
connect a preamplifier, please use one of them.
INPUT SELECTION:
Please press the button “INPUT SELECTION” 5.3 to use the BALANCED XLR input or release the
button to use the UNBALANCED RCA input.
You can use either the balanced input or the unbalanced input but not at the same time.
In order to connect this amplifier with a separate preamplifier, e.g. the PREAMP I from ACCUSTIC
ARTS®, please use interconnect cables with best possible shielding and high quality connectors. This
is the only way to ensure that the sound quality of the power amplifier is fully exploited.

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Pin declaration of the balanced input (XLR):
Pin 1: Ground Pin 2: positive phase Pin 3: negative phase
These pin assignments comply with the standard adopted by the Audio Engineering Society. Refer to
the operating manual of your balanced-output preamplifier to verify that the pin assignments of the
output connectors correspond to your ACCUSTIC ARTS® power amplifier.
IMPORTANT!
Please observe at all times!
Before you connect the power amplifier with some other units using a
cable, please never forget that both units must first be switched off.
5.2 Loudspeaker cables
For each channel the power amplifier has one pair of high quality protected loudspeaker terminals.
Please use only high quality loudspeaker cables. This is the only way to ensure that the sound quality
of the power amplifier is fully exploited.
Loudspeaker cables from ACCUSTIC ARTS® are excellently matched to the needs of the AMP I –MK
2. But naturally other high quality brand name products may also be used.
To connect the cables to the power amplifier or loudspeakers if possible use high quality terminal ends
or banana plugs*) and avoid connecting bare litz wires (except with OFC copper cables) since these
corrode and so restrict the signal flow.
IMPORTANT!
*) Instruction for the use of banana plugs:
Use only banana plugs with a corresponding CE conformity declaration. A CE
compatible, insulation-protected banana plug is available. For questions regarding
certain plug types please get in contact with your authorized dealer.
5.3 Correct phase for the loudspeakers
The terminals on your power amplifier and your loudspeaker are color coded or marked with a plus (+)
and minus (-). Connect the red (+) output terminal of your amplifier with the red (+) input terminal of
your loudspeaker. Proceed in the same way with the white or black (-) terminals.
IMPORTANT!
Avoid short circuits!
Never connect the output terminals of your power amplifier to each other. Neither
connect red (+) with white or black (-) of the channel nor the channels to each
other.

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5.4 Connection to mains power
Only connect the power amplifier to the mains power when all the other cable connections have
already been carried out.
Plug in the mains cable firstly in the inlet connector socket 1of the power amplifier and only then the
earthing pin-plugs in the mains socket.
By actuating the mains power switch 3, you can switch the unit on or off.
5.5 Replacing a damaged mains fuse
Replace fuses only with original types having the same ampere value, the same voltage endurance
and the same time-lag.
Never use fuses with other ampere classes or time-lag classes.
IMPORTANT!
Pull out the mains plug!
Always disconnect the unit from the mains power before replacing a fuse.
To change the fuse 2please use a screwdriver suitable for the slot in the fuse holder. Press the
screwdriver lightly into the slot and only then turn anticlockwise. Now you can take out the fuse holder
and replace the fuse.
For countries with 220- 240 V / 50- 60 Hz
please use the following fuse types:
For countries with 100-120 V / 50- 60 Hz
please use the following fuse types:
Fuse: 4 A –time lag
Fuse: 8 A –time lag
6 Start-up
Fig. 2: Front panel
6PROTECT: LED (red) indicates error on the right output stage channel
7ON: LED (blue) indicates ready for operation
8PROTECT: LED (red) indicates error on the left output stage channel

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6.1 Description of function
The red LED 6signals that the output relay of the right output stage channel is open and that means
that the transmission of a music signal to the connected loudspeaker is interrupted.
The blue LED 7in the middle signals that the unit is switched on (operational status).
The red LED 8signals that the output relay of the left output stage channel is open and that means
that the transmission of a music signal to the connected loudspeaker is interrupted.
By pressing the mains power switch 3on the rear side of the unit you connect the unit to the mains
power. After the switch is operated all three LEDs firstly light up. After approx. 5 seconds both red
LED’s go out while the blue LED 7indicates the operational status.
6.2 How to start the power amplifier
1. The unit can be switched on by pressing the mains power switch 3 on the rear panel.
2. After switching on the mains power-on/off switch all three LEDs will turn on. After approx. 5
seconds (“protection”) the two red ones will extinguish, while the blue LED 8stays on showing
that the unit is running.
IMPORTANT!
Switching on: Always switch on the power amplifier last, i.e. after the other
devices in your system (preamplifier, CD player, etc).
Switching off: Always switch off the power amplifier first and then switch off the
other devices from the mains power.
IMPORTANT!
After switching the unit off please wait 30 seconds before switching it on
again.
Avoid unnecessarily frequent switching the power amplifier on and off. The high
amount of switch-on current is a heavy burden for the electrical components and
so the life of the unit will be shortened by this action.
WARNING!
During a thunderstorm please completely disconnect the unit from the mains
power by pulling out the plug of the mains cable.
7 Looking after your amplifier
This high quality product from ACCUSTIC ARTS® does not require special treatment in excess of the
usual care taken with high quality devices. Clean the housing with a dry or slightly moistened cloth.
Please do not use any aggressive detergents or detergents which contain silicon.
The best way to clean the chromed inlay is with a mild non-aggressive fat-dissolving detergent (e.g.
glass cleaner). Use a very soft clean cloth and wipe the front plate with this without exerting strong
pressure. Never use abrasive agents or polishing agents with abrasive particles.
IMPORTANT!
Do not place the unit in direct sunshine and avoid extreme changes in
temperature.

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8 Troubleshooting
Malfunctions are mostly caused by something simple which can be put right quickly.
In the next section some possible malfunctions are described together with their corrective action.
However, if it is not possible to remove the malfunction please contact your authorized dealer.
Malfunction The unit was switched on, all the LEDs remain dark.
Cause 1 The mains cable is not properly connected.
Solution Check the mains cable and push in firmly.
Cause 2 The mains fuse is damaged.
Solution Pull out the mains plug and replace the respective fuse
(see Chapter 5.5).
Malfunction The unit is switched on, the blue LED 7 is illuminated but you hear no music.
Cause 1 The cables are not properly connected.
Solution Pull out the mains plug and check all connections (speaker cables etc.)
Malfunction The left and right LEDs do not go out approx. 5 seconds after switching on the
unit or light up during operation.
Cause A fuse inside the unit is damaged.
Solution Pull out the mains plug, carefully remove the housing cover and replace the respective
fuse. This replacement action should only be carried out by the authorized dealer.
Malfunction The left or right LEDs do not go out approx. 5 seconds after switching on the
unit or light up during operation.
Cause 1 The fuse 2 is damaged
Solution Pull out the mains plug and carefully replace the respective fuse.
(see Chapter 5.5)
Cause 3 Clipping due to overload of the power amplifier.
Solution Lower the volume on your control device (e.g. preamplifier).
Cause 4 Overheating of the unit.
Solution Switch off the unit for approx. 30 minutes and then make sure that the unit has
adequate cooling.
Cause 5 Short circuits at speaker outlet.
Solution Check the loudspeaker terminals an correct it if necessary
Malfunction Crackling or humming in the loudspeaker.
Cause Contact problems on the input sockets or on the loudspeaker terminals.
Solution Switch off the unit and check the contact on the input sockets and on the loudspeaker
terminals.

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9 Specifications
Voltage gain: 31.0 dB
Power consumption without load: 65 watts
Input voltage for output power
of 100 watts on 4 : 557 mV
Transformer output: 600 VA
Power supply capacity: more than 80,000 µF
Input impedance: RCA: 28 k
XLR: Pin 1 to Pin 2: 20 k
Pin 1 to Pin 3: 20 k
Pin 2 to Pin 3: 40 k
Rated power output: 2 x 210 watts on 4

2 x 140 watts on 8

(with THD+N = 0.1 %; mains voltage 230 VDC)
Rise time / fall time: 3.6 µs with 4 load (square-wave 20 kHz, 12 Vss)
Phase response: -17.5° with 20 kHz (10 watts on 4 )
Zero signal current setting: 265 mA per channel (mains voltage 230 V AC)
Crosstalk: > 88 dB with 1 kHz
Signal to noise ratio: -98 dBA (ref. 6.325 V)
Intermodulation distortion: 0.00019 % with 10 watts on 4 
(measured accord. to SMPTE 4:1 –60 Hz / 7 kHz)
Distortion factor (THD+N): 0.0078 % on 4 load with 1 kHz and 10 watts
(effective bandwidth 22 Hz –22 kHz)
Damping factor: more than 670 on 8 
Dimensions (H x W x D) 145 x 482 x 429 mm / 5.7 x 19 x 16.9 inches
Weight: approx. 20 kg / 44 lbs.
V-08