Art MX821S User manual

MX821S
EIGHT CHANNEL MIC/LINE MIXER WITH STEREO OUTPUTS
USER'S MANUAL

1
IMPORTANT SAFETY INSTRUCTIONS - READ FIRST
This symbol, wherever it appears, This symbol, wherever it appears, alerts
alerts you to the presence of uninsulated you to important operating and
dangerous voltages inside the enclosure maintenance instructions in the
that may be sufficient to constitute a risk. accompanying literature. Please read
of shock the manual.
Read instructions Retain these safety and operating instructions for future reference. Heed all
warnings printed here and on the equipment. Follow the operating instructions printed in this user
guide.
Do not open (except to convert the 1/4-inch jacks from inputs to outputs. See page 4.) There are no
user serviceable parts inside. Refer any service work to qualified technical personnel only.
Power sources Only connect the unit to mains power of the type described in this user guide or
marked on the rear panel. The power source must provide a good ground connection.
Power cord Use the power cord with sealed mains plug appropriate for your local main supply as
provided with the equipment. If the provided plug does not fit into you outlet consult your service
agent. Route the power cord so that it is not likely to be walked on, stretched or pinched by items
placed upon or against.
Grounding Do not defeat the grounding and polarization means of the power cord plug. Do not
remove or tamper with the ground connection on the power cord.
Moisture To reduce the risk of fire or electrical shock, do not expose the unit to rain, moisture or use
in damp or wet conditions. Do not place containers of liquid on it, which may spill into any openings
Heat Do not locate the unit in a place close to excessive heat or direct sunlight, as this could be a fire
hazard. Locate the unit away from any equipment which produces heat, such as power supplies,
power amplifiers and heaters.
Environment Protect from excessive dirt, dust, heat, and vibration when operating and storing.
Avoid tobacco ash, drink spillage and smoke, especially that associated with smoke machines.
Handling Protect the controls from damage during transit. Use adequate padding if you need to ship
the unit. To avoid injury to yourself or damage to the equipment, take care when lifting, moving or
carrying the unit.
Servicing Switch off the equipment and unplug the power cord immediately if it is exposed to
moisture, spilled liquid or the power cord or plug becomes damaged during a lightning storm or if
smoke odor or noise is noted. Refer servicing to qualified technical personnel only.
Installation Install the unit in accordance with the instructions printed in the user guide.

2
INTRODUCTION
The ART MX821S Eight Channel Mic/Line Mixer with Stereo Outputs is a versatile rack mount mixer
combining eight independent input channels into a stereo line-level output. Each input channel
accepts a balanced XLR microphone input or unbalanced 1/4-inch TS line-level signal and provides
independent level and pan controls. +48 Volt phantom power may be independently selected on each
microphone input. A master level control adjusts the signal output to the low-impedance balanced
1/4-inch TRS jacks. Prefade output (not affected by the master level control) and Aux Bus input RCA
jacks allow patching of multiple units when more channels are needed.
The ART MX821S may be used on stage, in the studio, or for permanent install applications
including conference rooms, corporate boardrooms, churches, restaurants, small clubs, health clubs
and more. A built-in power supply and single high 19-inch rack mount format allows for easy
installation and reliable long-term operation.
Features:
• Eight input channels with individual level and pan controls
• Pan controls place each input mono signal anywhere in the output stereo image
• Balanced microphone XLR or unbalanced 1/4-inch TS inputs on each channel
• Full +48V low noise phantom power switchable for each microphone input
• Balanced left and right 1/4-inch TRS main output jacks with master level control
• Prefade Output jacks and Aux Bus Input jacks allow units to be chained to provide extra inputs
• Each line input jack may be individually converted to a direct line output by means of internal
jumpers
• Rugged 1U rack-mount steel chassis with built-in power supply
• Perfect for stage, studio and permanent installations
• Three year warranty

3
CONNECTIONS
Rear Panel Connections
Mono CHANNEL Inputs (1-8)
MIC
Each of these eight female XLR connectors provides a balanced input for lower level microphone
signals. An additional 26 dB of gain is provided for use with low output level mics. 48V phantom
power is available to operate microphones that contain active electronic circuitry (such as condenser
mics) and may be applied by setting the corresponding +48V PHANTOM POWER switch in the down
(ON) position. These switches are located towards the right of the rear panel. Note: Do not apply
phantom power unless the microphone is designed to use it.
LINE
Each of these eight 1/4-inch jacks normally provides an unbalanced input for line level signals. Use
shielded cables with 1/4-inch TS plugs to connect to these jacks.
To convert the 1/4-inch line input on any channel to a direct line output for that channel, unplug the
MX821S’s AC cord from the wall and remove the top cover. Inside you will see a row of jumpers
towards the rear of the unit. Move the jumper for the desired channel to the left (when viewed from
the front). Now that channel’s line input is converted to a direct line output and may be connected to
the input of another mixer. A signal from the MIC input on any converted channel is still included in
the main output mix as well. Do not connect the output of a mixer or any other signal source to the
1/4-inch jack on this channel now or the channel may sustain damage. Be sure to replace the lid
before connecting the unit to AC again.
Both the MIC and LINE inputs accept a mono signal that may be routed to either the left or right
channels or a combination of both by means of the corresponding front panel PAN control.

4
OPERATION
Front Panel Controls
POWER Switch
Controls the application of AC power to the MX821S. When the switch is pushed in at the top (ON
position), the green POWER LED lights, showing power is applied.
MASTER LEVEL Control
This control adjusts the overall level of the mixed signal output to the MAIN OUTPUTS (LEFT and
RIGHT) jacks.
CHANNEL Controls (1-8)
LEVEL
Each of these controls adjusts the level of the associated input channel and determines its
contribution to the overall mix. Each control should be adjusted for the desired level of the associated
input in the overall mix. Unused inputs should have their associated level control turned off (0 position
or fully counterclockwise) to minimize potential stray noise pickup.
Keep in mind that the best noise performance, while keeping distortion to a minimum, is obtained
with each control adjusted to the maximum desired level (towards 10) so that its associated red CLIP
LED either does not come on or just comes on very briefly only during the loudest passages. In other
words, in general, keep the CHANNEL LEVEL controls turned up and turn the MASTER LEVEL
control down to compensate, rather than the opposite.

5
PAN
Each of these controls adjusts the relative position of the associated input channel in the overall left-
right panorama. Fully counterclockwise is Left and fully clockwise is Right.
Rear Panel Controls
+48V PHANTOM POWER Switches (1-8)
These numbered switches control the application of phantom power to the corresponding numbered
rear-panel MIC XLR connectors. In the OFF position (up), no phantom voltage is applied. Moving the
switch down (ON position) applies phantom voltage. Note that when phantom voltage is applied, the
current supplied is limited to 7 mA for each leg of the balanced line.

6
BLOCK DIAGRAM

7
WARRANTY INFORMATION
Limited Warranty (USA only)
Applied Research and Technology will provide warranty and service for this unit in accordance with
the following warrants:
Applied Research and Technology, (ART) warrants to the original purchaser that this product and
the components thereof will be free from defects in workmanship and materials for a period of three
years from the date of purchase. Applied Research and Technology will, without charge, repair or
replace, at its option, defective product or component parts upon prepaid delivery to the factory
service department or authorized service center, accompanied by proof of purchase date in the form
of a valid sales receipt.
Online Registration
We recommend that you register your product online to insure prompt warranty repair servicing on
any repair issues. Please go to www.artproaudio.com. Select “Support”, then "Product Registration".
Then input your information here.
Exclusions
This warranty does not apply in the event of misuse or abuse of the product or as a result of
unauthorized alterations or repairs. This warranty is void if the serial number is altered, defaced, or
removed.
A R T reserves the right to make changes in design or make additions to or improvements upon this
product without any obligation to install the same on products previously manufactured.
A R T shall not be liable for any consequential damages, including without limitation damages
resulting from loss of use. Some states do not allow limitations of incidental or consequential
damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific
rights and you may have other rights, which vary from state to state.
For units purchased outside the United States, an authorized distributor of Applied Research and
Technology will provide service.

8
SERVICE
The following information is provided in the unlikely event that your unit requires service.
1. Be sure that the unit is the cause of the problem. Check to make sure the unit has power, all
cables are connected correctly, and the cables themselves are in working condition. You may
want to consult with your dealer for assistance in troubleshooting or testing your particular
configuration.
2. If you believe that the ART unit is at fault, go to www.artproaudio.com.
3. Select “Support”, then “Return Authorization Request” to request a return authorization number.
4. If you are returning the unit for service, pack the unit in its original carton or a reasonable
substitute. The original packaging may not be suitable as a shipping carton, so consider putting
the packaged unit in another box for shipping. Print the RA number clearly on the outside of the
shipping box. Print your return shipping address on the outside of the box.
5. Include, with your unit, a note with the RA number and your contact information, including a
return shipping address (we cannot ship to a P.O. box) and a daytime phone number, and a
description of the problem, preferably attached to the top of the unit. Also include a copy of your
purchase receipt.
Please fill in the following information for your reference:
Date of purchase: __________________________________
Purchased from: __________________________________
Serial Number: __________________________________

9
SPECIFICATIONS
Input Connections XLR female balanced (Mic, channels 1-8)
1/4-inch TS unbalanced (Line, channels 1-8)
RCA unbalanced (Aux Bus In, Left and Right)
Output Connections 1/4-inch TRS balanced (Main Outputs, Left and Right)
RCA unbalanced (Prefade Out, Left and Right)
Input Impedance 2k Ohms (Mic), 20k Ohms (Line), 51k Ohms (Aux Bus In)
Output Impedance 200 Ohms (Main Outputs, balanced),
100 Ohms (Prefade Out)
Frequency Response 20 Hz – 20 kHz (+0, -1 dB) (CH 1-8 in, Main out)
THD <0.01% @ 1 kHz, typical
Phase Response All connections are phase coherent
Signal to Noise Ratio >99dB typical (Ref 0dBu)
CMRR >43 dB typical
All PAN controls centered for the following level and gain measurements:
Maximum Input Level -4 dBu (Mic), +22 dBu (Line)
Maximum Output Level +24 dBu (balanced), +18 dBu (unbalanced)
Maximum Gain 54 dB (Mic), 29 dB (Line)
Phantom Power Switch selectable, +48V DC (regulated and filtered),
7 mA current limiting per leg
Power Requirements USA: 95-125 VAC, 50-60 Hz, <15W
Export units configured for country of destination
Dimensions (HWD) 1.75-inch x 19-inch x 6-inch
44.5mm x 483mm x 152mm
Weight 6.3 lbs. (2.9 kg)
Note: 0 dBu = 0.775Vrms
ART maintains a policy of constant product improvement. ART reserves the right to make changes
in design, or make additions to, or improvements upon, this product without any obligation to install
same on products previously manufactured. Therefore, specifications are subject to change without
notice.

www.artproaudio.com
E-mail: [email protected]
© 2017 Applied Research & Technology
MX821S 821S5004103
EIGHT CHANNEL MIC/LINE MIXER WITH STEREO OUTPUTS