641 Integrated Amplifier

Product Information

Specifications

• Model: 641 Integrated Amplifier
• Date: 2024-05-06

Product Usage Instructions

Front Panel

The front panel of the integrated amplifier includes various
controls and indicators for adjusting the audio settings. These may
include volume knobs, input selection buttons, display screens, and
power buttons.

Rear Panel

The rear panel of the amplifier houses input and output
connections for audio sources and speakers. Make sure to connect
the appropriate cables to the corresponding inputs and outputs for
optimal performance.

Safety Instructions

1. Read and keep these safety instructions for reference.

2. Only use attachments and accessories specified by the
   manufacturer to avoid damage or malfunctions.

3. Ensure the amplifier is handled by two people due to its weight
   to prevent injuries.

4. Avoid placing the amplifier near water sources to prevent
   electrical hazards.

5. Clean the amplifier with a dry cloth only to prevent damage
   from moisture.

6. Do not block ventilation openings to maintain proper airflow
   and prevent overheating.

7. Avoid installing the amplifier near heat sources to prevent
   damage or fire hazards.

8. Protect the power cord from being pinched or walked on to avoid
   electrical damage.

9. Refer servicing to qualified personnel if the amplifier is
   damaged or exposed to moisture.

10. Avoid placing naked flame sources on the amplifier to prevent
    fire hazards.

Additional Safety Information

Ensure the amplifier is not exposed to rain or moisture to
reduce the risk of electric shock. Do not attempt to open the
amplifier as there are no user-serviceable parts inside. Refer all
servicing to qualified personnel for maintenance and repairs.

The CE symbol on the product indicates compliance with EMC and
LVD standards of the European Community.

Frequently Asked Questions (FAQ)

Q: Can I use any type of cable to connect my audio sources to

the amplifier?

A: It is recommended to use high-quality audio cables suitable
for your devices to ensure optimal sound quality and
performance.

Q: How should I clean the amplifier?

A: Use a dry cloth to gently wipe the surfaces of the amplifier.
Avoid using any liquid cleaners or solvents that may damage the
product.

Q: What should I do if the amplifier stops working

suddenly?

A: Check the power connection, fuses, and ensure all cables are
properly connected. If the issue persists, contact customer support
or a qualified technician for assistance.

641
integrated amplifier
2024-05-06

Contents
Important Safety Instructions…………………………………………………………………………………………………………2 Explore new frontiers……………………………………………………………………………………………………………………5 Before getting started …………………………………………………………………………………………………………………… 6 Install your MOON 641 ……………………………………………………………………………………………………………….. 7 Get to know your MOON 641 ………………………………………………………………………………………………………. 8
Front Panel …………………………………………………………………………………………………………………………………………………. 8 Rear Panel ………………………………………………………………………………………………………………………………………………….. 9
Audio Connections ……………………………………………………………………………………………………………….. 9 Functional ………………………………………………………………………………………………………………………….. 10 Personalize your MOON 641……………………………………………………………………………………………………….11 Setup Menu ………………………………………………………………………………………………………………………………………………. 11
Navigating the Menu …………………………………………………………………………………………………………………………… 11 Editing Text ……………………………………………………………………………………………………………………………………….. 11 Connectivity ………………………………………………………………………………………………………………………. 11 Inputs ………………………………………………………………………………………………………………………………………………… 11 Line Output………………………………………………………………………………………………………………………………………… 11 Network …………………………………………………………………………………………………………………………………………….. 11 Functionality………………………………………………………………………………………………………………………. 12 Remote Control…………………………………………………………………………………………………………………………………… 12 MOONLink ……………………………………………………………………………………………………………………………………….. 12 Display………………………………………………………………………………………………………………………………………………. 12
Display On ……………………………………………………………………………………………………………………………………… 12 Brightness ………………………………………………………………………………………………………………………………………. 12 Background Image …………………………………………………………………………………………………………………………… 12 Screen Saver …………………………………………………………………………………………………………………………………… 13 Volume Settings …………………………………………………………………………………………………………………………………. 13 Standby Settings …………………………………………………………………………………………………………………………………. 13 Firmware……………………………………………………………………………………………………………………………………………. 13 Information ………………………………………………………………………………………………………………………………………… 13 Reset …………………………………………………………………………………………………………………………………………………. 13 Troubleshooting ………………………………………………………………………………………………………………………… 14 Error Messages………………………………………………………………………………………………………………………………………….. 14 firmware update error ………………………………………………………………………………………………………….. 14 temperature protection………………………………………………………………………………………………………….14 voltage protection ……………………………………………………………………………………………………………….. 14 DC protection …………………………………………………………………………………………………………………….. 14 Specifications ……………………………………………………………………………………………………………………………. 15 Technical ………………………………………………………………………………………………………………………………………………….. 15
2024-01-01

Important Safety Instructions

1. Read these instructions.

11. Only use attachments and accessories specified by the

2. Keep these instructions.

manufacturer.

3. Heed all warnings.

12. The apparatus is heavy and requires two people to lift it. Exercise

4. Follow all instructions.

caution when maneuvering.

5. Do not use this apparatus near water.

13. Use only with the cart, stand, tripod, bracket, or table specified by the

6. Clean only with a dry cloth.

manufacturer or sold with the apparatus. When a cart is used, use caution when

7. Do not block ventilation openings. Install in accordance with the

moving the cart/apparatus combination to avoid injury from tip over.

manufacturer’s instructions.

14. Unplug this apparatus during lightning storms or when unused for long

8. Do not install near heat sources such as radiators, heat registers, stoves or

periods of time.

another apparatus that generate heat.

15. Refer all servicing to qualified service personnel. Servicing is required when

9. Do not defeat the safety purpose of the polarized or grounding-type plug. A

the apparatus has been damaged in any way such as when the power cord has

polarized plug has two blades with one wider than the other. A grounding-

been damaged; liquid has been spilled or objects have fallen into the

type plug has two blades and a third grounding prong. The wide blade or the

apparatus; or the apparatus has been exposed to rain or moisture, does not

third prong is provided for safety. If the provided plug does not fit into the

operate normally, or has been dropped.

outlet, consult an electrician to replace the obsolete outlet.

16. No naked flame sources, such as candles, should be placed on the apparatus.

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. Unplug mains cord during transportation.

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.
CAUTION RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE COVER. NO USER- SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.

The lightning flash with the arrowhead symbol, 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 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 (shown right) indicates compliance of this device with the EMC (Electromagnetic Compatibility) and LVD (Low Voltage Directive) standards of the European Community.
Waste from Electrical and Electronic Equipment (WEEE): This equipment must be sent to a separate collection facility for the recovery and recycling of electrical and electronic waste wherever dedicated facilities exist. WEEE regulations aim to contribute to sustainable production and consumption, addressing environmental and other issues caused by the growing number of discarded electronics. The symbol for the separate collection of electrical and electronic equipment indicates that this product should not be discarded as unsorted waste.
Hot Surface The side panels are heat sinks, which could become dangerously hot while the device is in operation. Caution: Do not touch

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1. ALWAYS disconnect your entire system from the AC mains before 6. NEVER operate the unit with any covers removed. There are no user-

connecting or disconnecting any cables, or when cleaning any component. To

serviceable parts inside. An open unit, especially if it is still connected to an

completely disconnect this apparatus from the AC mains, use the rocker

AC source, presents a potentially lethal shock hazard. Refer all questions to

switch on the rear panel or disconnect the power supply cable from the AC

authorized service personnel only.

receptacle.

7. NEVER wet the inside of the unit with any liquid. If a liquid substance does

2. The unit must be terminated with a three-conductor AC mains power cord,

enter your unit, immediately disconnect it from the AC mains and take it to

which includes an earth ground connection. To prevent shock hazard, all three

your MOON Partner for a complete check-up.

connections must ALWAYS be used. Connect the unit only to an AC source 8. NEVER spill or pour liquids directly onto the unit.

of the proper voltage; both the shipping box and rear panel serial number label 9. NEVER block air flow through ventilation slots or heatsinks.

will indicate the correct voltage. Use of any other voltage will likely damage 10. NEVER bypass any fuse.

the unit and void the warranty.

11. NEVER replace a fuse with a value or type other than those specified.

3. ALWAYS connect the unit only to an AC source of the appropriate voltage. 12. NEVER attempt to repair the unit. If a problem occurs, contact a MOON

Both the shipping box and rear panel serial number label indicate the correct

Partner.

voltage. Incorrect voltage could damage the unit and void the warranty.

13. NEVER expose the unit to extremely high or low temperatures.

4. AC extension cords are NOT recommended for use with this product. The 14. NEVER operate the unit in an explosive atmosphere.

mains plug of the power supply cord shall remain readily accessible.

15. ALWAYS keep electrical equipment out of reach of children.

5. NEVER use flammable or combustible chemicals for cleaning audio 16. ALWAYS unplug sensitive electronic equipment during lightning storms.

components.

17. WARNING: Do not expose batteries or battery pack to excessive heat such

as sunshine, or fire or the like.

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MOON 641 |4

Explore new frontiers
The landmark North Collection represents the culmination of years of research and development in the fields of audio, electronics, materials, and manufacturing processes. Its exciting new look is surpassed only by improvements in performance made possible by the passionate team of Simaudio engineers and technicians dedicated to delivering an uncompromised music listening experience. With the purchase of this MOON product, you join an elite group of music lovers around the world who expect the absolute best performance and build quality from products in any class.
Get ready for the performance of a lifetime.

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Before getting started
Carefully remove the unit from its packaging. Visually inspect it, and in the case of damage, report it to your MOON Retailer immediately.
The packaging materials were designed to protect this product while in transit. Store these materials in a dry location for the duration of the warranty period.
The information contained in this Manual is subject to change without notice. The most recent version is available at simaudio.com/guides-downloads.
The MOON 641 includes:
· Quick Start Guides (2) · MOON BRM-1 Remote Control · Power Cable · Ethernet Cable · USB Cable · Warranty Registration Card (Canada & USA only)
Note the serial number of your MOON 641 for future reference.

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MOON 641 |6

Install your MOON 641
Consider the location and environment of the device carefully. Set it upon an open, stable, and flat surface. The device requires sufficient space above and around it to adequately disperse the heat it generates. Maintain a minimum gap of 5 cm (2″) around the sides and 10 cm (4″) above of the unit to enable airflow. When stacking multiple units, install MOON Bridges (sold separately) between them.
The performance of this device will continue to improve during the first 100 hours of listening.

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Get to know your MOON 641 Front Panel

Standby toggles the device between active and inactive modes when the device is powered on
Mute cuts and restores the audio signal to all outputs
Adjusting the volume also restores muted audio.
Input scrolls and through available inputs
The display provides useful feedback about the state of the device.
· It identifies the active input and volume of the device. · It also serves as the visual interface for the configuration menu.
Setup accesses the extensive configuration menu to personalize the device
To navigate the menu…
· Use the volume knob to scroll through the options. · Use OK to confirm a selection or Setup to cancel it.
OK selects or confirms on-screen prompts
The rotary knob adjusts volume and interfaces with the configuration menu. · Rotating the knob adjusts the volume in 1.0 dB increments between 0 and 20, and in 0.5 dB increments between 20 and 80. · The knob also navigates the interface for the configuration menu.

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MOON 641 |8

Rear Panel
Audio Connections
ANALOG INPUTS A1 ­ A4 single-ended (RCA) connections for unbalanced line-level analog source devices BALANCED differential (XLR) connections for balanced analog line-level source devices LINE OUT individually configurable
Output Types
· VARIABLE: for use as a preamplifier connecting to power amplifiers, subwoofers, and active loudspeakers
· FIXED: for connecting to headphone amplifiers and other devices with integrated volume control
For more information, see Connectivity. SPEAKER OUTPUTS +/­ binding posts for connecting loudspeakers
Insert banana pins through the holes in the extremities of the barrels or unscrew the barrels to expose a gap underneath for spades and bare wire contacts.

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Functional
12V TRIG OUT mini-jack (TS) connection for coupling a compatible power amplifier to synchronize Standby behaviours
NETWORK network (RJ-45) connections for Ethernet cables
· for MOONLink functionality with compatible MOON products · for extending the network to an additional device (eg, NAS device or TV) · for connecting the device to a network router
FUSE magazine containing a power supply fuse
Please appreciate that while some users may report improvements in the performance of their audio equipment when original parts are replaced with after market parts, MOON cannot guarantee the proper functioning of its products under such conditions. Our engineers have ensured that the original fuse should protect your device from catching fire due to electrical calamities. All security, quality, and performance testing, as well as standards certification, is performed with specific components, and any modification from the original design may void its warranty.
AC connecter & power switch for connecting power cable and toggling the device on I and off O
With the power switch on, the unit may be toggled in and out of Standby using the button on the front panel, a remote control, the MiND Controller, or by MOONLink. The unit may require up to a minute to connect to the network. For best performance, the device should remain powered up and may be toggled into Standby when not in use. It should be powered down during extended absences by disconnecting the power cable.
Always power on the source devices before the integrated amplifier.
Always power off the integrated amplifier before the source devices.

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Personalize your MOON 641
Setup Menu
The device features an extensive menu for configuring and customizing many of its functions.

Navigating the Menu The Setup button enters the menu and returns to previous screens. The knob rotates to scroll through options. The OK button selects the emphasized option.
Editing Text The knob rotates to reveal uppercase letters, lowercase letters, digits, and symbols. The Input and buttons move the cursor left and right.
When the complete text is correctly displayed and the cursor remains on the last character, the OK button registers the text.
Note: Do not advance the cursor beyond the last desired character.
Connectivity Inputs Each input may be personalized.

Setup
Inputs Line Output Network Remote Control MOONLink Display Volume Settings Standby Settings Firmware Information Reset

· Label is the name of the input as it appears on the display. Select a predefined label or manually enter a custom label.
· Offset is a variable amount of gain applied to each input to fine-tune its volume level so that source components connected to all inputs may have similar levels.
· Home Theatre Bypass disables volume control in this device. This mode sets the preamp volume to unity gain for use with a separate audio-video receiver or home theater processor. There is an additional prompt to confirm that a device with its own volume control is connected to the input of the MOON 641 before activating this mode.
· Enable makes an input available to select. It may be disabled to reduce the number of unused inputs to scroll through.

Line Output The RCA outputs may be configured as a Variable-volume output for use as a preamplifier (eg, with a subwoofer) or as a Fixed-volume output for use with a device with its own volume control (like a headphone amplifier).
Caution: The fixed volume level is extremely high! Before setting the analog output of this device to Fixed, lower the volume of the preamp or integrated amp to which it is connected.
Network
Upon powering on the device, it automatically attempts to connect to a wired network.

· The Configuration of the network is either Automatic or Manual. Manual Configuration permits the configuration of specific advanced network parameters including IP address, subnet mask, gateway address, and DNS server.
· Information displays useful details about the network connection of this device.

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Functionality Remote Control This unit may link with up to two BRM-1 remote control units at a time.
· Link Remote searches for a nearby MOON BRM-1 remote control, displaying its unique ID on both devices and permitting them to be associated.
· Unlink Remote displays associated BRM-1 units permitting them to be disassociated from this device. · Information displays useful details about the associated BRM-1 units.
Refer to the separate Guide included with the BRM-1 for more information.
MOONLink MOONLink technology makes MOON products more intelligent.
A single button press can trigger automated behaviours and simultaneously operate multiple devices over a network in a symbiotic MOONLink Group. MOONLink simultaneously toggles Standby and can adjust display brightness for all devices in the Group, while enabling volume control and automatic input selection of specific devices in the Group.
· MOONLink Group permits the customization of a Group. o Name identifies a device within the Group. o Group ID assigns a Group number to a Device. Assigning the same ID to other devices joins them together as a Group. o Status lists information about the device. o Reset the name and ID to their default values to remove a device from a Group. o Firmware verifies the firmware of the selected device and updates it when necessary.
· Available Devices lists devices on the network that could be added to a Group. · MOON DAC identifies which input is used to connect a DAC with MOONLink compatibility.
1. When scrolling through the inputs on a BRM-1, an additional arrow appears on the selected input. 2. Tapping the centre of the display switches the BRM-1 to selecting the inputs on the DAC. · A MOONLink Group should include no more than one preamplifier, and there is already a preamplifier integrated within this device. · Holding the Standby button on the front panel for two seconds automatically toggles Standby mode on all the devices in the MOONLink Group.
Display Display On The display may be disabled so that only user interaction temporarily activates the display.
Brightness The display brightness is variable and may be customized.
· Brightness Level is a value from 0% to 100%. · Adaptive Brightness uses sensors to adjust automatically to ambient lighting in the environment. · MOONLink Brightness Sync duplicates the brightness adjustments of this device on other devices in the
MOONLink Group.
Background Image This device displays a pre-defined background image or none at all.

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Screen Saver Two screen saver styles are available, which may also be disabled.
· Mode determines what triggers the screen saver. o One mode activates the screen saver after 20 minutes of silence. o One mode activates the screen saver after 20 minutes of inactivity.
· Style sets the automatic screen saver to display a blank screen or a floating MOON logo.
Volume Settings The highest volume setting of the preamp is 80.
· Startup Volume sets a default initial volume level. · Maximum Volume level sets an upper threshold to prevent accidents.
Standby Settings · Full Power keeps most of the electronics powered up while in Standby. · Low Power powers down most of the electronics while in Standby. · Auto-Standby engages Low Power Standby after 20 minutes of inactivity.
Firmware Certain hardware components in this device require firmware to function.
· Versions displays the various firmware versions currently installed. · Update begins the procedure of verifying and, if necessary, updating the firmware with on-screen guide prompts.
Information Device information, including its serial number, and certifications are displayed for referencing.
Reset The Reset procedure reverses all customizations (including input configurations) to factory default settings. It does not revert the firmware to an earlier version.

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Troubleshooting Error Messages
If typical operation is disrupted, the device may display a message on its display.
firmware update error Normally, the device recovers automatically from a firmware update error. If the problem persists…
1. Verify that the device is connected to the network and that the network is accessing the Internet. 2. Wait 30 minutes. 3. If the device continues to indicate a firmware update error, contact support@simaudio.com.
temperature protection If a device overheats, it could return to normal operation after a period of cooling down.
1. Power down the device using the rear rocker switch. 2. Wait 10 minutes. 3. Consider the location and environment of the device carefully. Make adjustments to decrease the temperature and
increase airflow around the device. 4. Power up the device and resume normal operation. 5. If the device continues to indicate temperature protection, contact support@simaudio.com.
voltage protection If a device has a voltage issue, it will most likely require service.
1. Power down the device using the rear rocker switch. 2. Wait 60 seconds. 3. Power up the device and resume normal operation. 4. If the device continues to indicate voltage protection, contact support@simaudio.com.
DC protection The device will shut down if it detects DC at its input, internally, or at its output. To determine the source of the issue…

1. Power down the device using the rear rocker switch. 2) Disconnect all cables from the device. 3) Wait 60 seconds. 4) Reconnect only the power cable.
2. Power up the device.
   a) If the device continues to indicate DC protection, contact support@simaudio.com. b) If not… 6) Reconnect one loudspeaker. a) If the device indicates DC protection, there is an issue with that loudspeaker or its cable. b) If not, connect the other loudspeaker. c) If the device indicates DC protection, there is an issue with that loudspeaker or its cable. d) If not…
3. Reconnect one source device. a) If the device indicates DC protection, there is an issue with that device or its cable. b) If not, continue this process of elimination.

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Specifications Technical
Output Power (Stereo 8 ) 125 W Output Power (Stereo 4 ) 250 W
Input Sensitivity 300 mV ­ 6 V Input Impedance 22 k
Gain 40 dB Frequency Response 2 Hz ­ 90 kHz (+0 dB / ­3.0 dB)
Crosstalk ­109 dB Total Harmonic Distortion @ 1 W 0.008% Total Harmonic Distortion @ 125 W 0.003%
Intermodulation Distortion 0.06% Signal-to-Noise Ratio 109 dB Damping Factor 700
Power Consumption (Idle) 38 W Power Consumption (Standby) 37 W Power Consumption (Low Power Standby) 2.5 W
Shipping Weight 26 kg / 57.5 lbs Dimensions (L x H x D) 48.1 cm x 10.2 cm x 46.5 cm / 18.95″ x 4.03″ x 18.32″
Fuse (120 V / 240) F 6A H 250V 3AG / F 4A H 250V 3AG

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References

• High End Audiophile Amplifiers And Sound Systems | MOON - Simaudio
• Guides & Downloads | MOON - Simaudio

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