Stewart Audio AV30MX-2 User manual

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AV30MX-2 Operation Manual
1Important safety instructions
1. Please read carefully prior to product installation or operation.
2. Read these instructions.
3. Keep these instructions.
4. Heed all warnings.
5. Follow all instructions.
6. Do not use this apparatus near water.
7. Clean only with dry cloth.
8. Do not block any ventilation openings. Install in accordance with manufacturer’s instructions.
9. Do not install near any heat sources such as radiators, heat registers, stoves, or other
apparatus (including amplifiers) that produce heat.
10. The unit should only be connected to 120-240VAC, 50-60 Hz power supply. Use only the
power adapter that is sold with the unit.
11. Protect the power cord from being walked on or pinched particularly at plugs, convenience
receptacles, and the point they exit from the apparatus.
12. Only use attachments/accessories specified by the manufacturer.
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 required 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 exposed to rain or
moisture, does not operate properly, or has been dropped.
2Approvals
This equipment has been tested and found to be compliant with the limits for Class A Digital device
pursuant to part 15 of the FCC rules, and in compliance with the EN55022 and EN55024 EMC
standards.

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3Warnings
3.1 Explanation of Warning Symbols
3.1.1 Lightning Bolt
The lightning bolt within arrowhead symbol, within an equilateral triangle, is intended to alert the user to
the presence of un-insulated “dangerous voltage” within the product’s enclosure that may be of sufficient
magnitude to constitute a risk of electrical shock to person.
3.1.2 Exclamation Point
The exclamation point within an equilateral triangle is intended to alert the user to the presence of
important operating and maintenance (servicing) instruction in the literature accompanying the appliance.
3.2 Warnings
WARNING: TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT EXPOSE THIS PRODUCT TO
RAIN OR MOISTURE. DANGEROUS HIGH VOLTAGES ARE PRESENT INSIDE THE ENCLOSURE. DO
NOT OPEN THE CABINET. REFER SERVICING TO QUALIFIED PERSONNEL ONLY.
3.3 User Responsibility
3.3.1 Radio Interference
This product has been tested and complies with the EMC directive, and with FCC part 15 Class A. If
this product is not used in accordance with these operating instructions, it may cause interference
with to other equipment, such as radio and television receivers.
3.3.2 Maintenance
Clean regularly with a soft cloth to remove dust and debris. Also check that vent holes and slots
are not covered and that there is adequate ventilation for convection cooling.

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4Table of Contents
1 Important safety instructions.....................................................................................................................1
2 Approvals....................................................................................................................................................1
3 Warnings.....................................................................................................................................................2
3.1 Explanation of Warning Symbols.................................................................................................. 2
3.1.1 Lightning Bolt........................................................................................................................ 2
3.1.2 Exclamation Point................................................................................................................. 2
3.2 Warnings....................................................................................................................................... 2
3.3 User Responsibility ....................................................................................................................... 2
3.3.1 Radio Interference................................................................................................................ 2
3.3.2 Maintenance......................................................................................................................... 2
4 Table of Contents .......................................................................................................................................3
5 Welcome.....................................................................................................................................................4
5.1 Features........................................................................................................................................ 4
5.2 Unpacking and Visual Inspection.................................................................................................. 4
5.3 Installation and Setup................................................................................................................... 4
5.3.1 Mounting .............................................................................................................................. 4
5.3.2 Product Dimensions.............................................................................................................. 5
5.3.3 Cooling Considerations......................................................................................................... 5
5.3.5 Input Connections................................................................................................................. 6
5.3.6 Output Connections.............................................................................................................. 6
6 Controls and Indicators ..............................................................................................................................7
6.1 Sleep Mode................................................................................................................................... 7
6.2 Level Controls ............................................................................................................................... 7
6.3 Remote Mute................................................................................................................................ 7
7 Technical Specifications..............................................................................................................................8
8 Troubleshooting .........................................................................................................................................9
9 Warranty Information ..............................................................................................................................10
9.1 Warranty Summary .................................................................................................................... 10
9.2 Eligibility Requirements.............................................................................................................. 10
9.3 Non-warranty Repairs................................................................................................................. 10
9.4 Shipment Instructions ................................................................................................................ 11
9.5 Packaging Instructions................................................................................................................ 11
10 Accessories ...............................................................................................................................................12

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5Welcome
Your Stewart Audio AV Series amplifier is the result of years of experience in the design and
manufacture of quality amplifiers. As such it provides a combination of performance and
operational benefits that simply cannot be found in conventional amplifiers.
5.1 Features
Sub Compact 1/4 rack package
Two channel stereo amplifier with built-in mixing capabilities
Optimized to drive 4 and 8 ohm loads.
Music and fire alarm muting
Clean full–range dynamic power
Signal Detect trigger for sleep & wake up
Multiple mounting options
External inline power supply
Class D convection cooled
This product is proudly manufactured in the United States.
5.2 Unpacking and Visual Inspection
Every Stewart Audio product is carefully tested and inspected before leaving the factory and
should arrive in perfect condition. If any damage is discovered, please notify the shipping carrier
immediately. Save the packing materials for the carrier’s inspection and for any future shipping.
5.3 Installation and Setup
5.3.1 Mounting
There are a number of different mounting options for the AV30MX/PMX-2 to meet a variety of
installation requirements.
5.3.1.1 Pole Mounting
The AV30MX-2 has mounting holes on both the top and side of the unit which can be used with
the AV-Pole bracket available from Stewart Audio.
Part Number: AV-Pole

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5.3.1.2 Universal Mounting
The AV30MX-2 also has a universal bracket available which allows
the unit to be mounted against a wall or under a table. Two
screws are included in the kit which will affix the bracket to the top
of the unit. Once this is done, two holes are available for mounting
the unit where desired.
CAUTION: Use only the screws provided in mounting the brackets to the
unit. Do not over tighten.
5.3.2 Product Dimensions
5.3.3 Cooling Considerations
Because the AV30MX-2 is cooled by convection with no fans, the amplifier must be given adequate
space to allow for proper airflow. Do not stack the amplifiers on top of each other or mount it in a
way that other equipment will block airflow around the case.
CAUTION: Inadequate air flow can cause the amplifier to overheat and potentially become damaged. Be
sure to provide plenty of air space to allow for convection cooling.
Part Number: AV-Bracket

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5.3.5 Input Connections
Your AV30MX-2 has two independent stereo inputs which are then mixed into the final output.
Input 1 will accept a stereo 3.5mm jack while input 2 will accept stereo RCA phono plugs. Both
inputs should be stereo, unbalanced, and line-level. Note that the input sensitivity is 0.5V
(-6dBV). Do not overdrive the amplifier! The AV30MX-2 does not include a pre-amplifier. Refer
to the diagrams below for proper wiring for the 3.5mm and RCA inputs.
5.3.6 Output Connections
Stewart Audio recommends using high-quality, heavy-gauge speaker wire and connectors to send
the output signal of your amplifier to the speakers. Use the following table as a guideline when
selecting your wire gauge.
Distance
Wire Gauge
Up to 25 ft (up to 8 m)
16 AWG
25-40 ft (8-12 m)
14 AWG
40-60 ft (12-18 m)
12 AWG
Speaker leads connect by means of terminal block connectors supplied with the unit.
Strip speaker leads 1/4” (6.4mm) and insert into connector observing proper
polarity. With a small, flat-blade screwdriver, tighten the screw until the leads are
held securely in place. Inspect for possible shorts or broken wires.
The AV30MX-2’s two stereo inputs are mixed and then sent to the left and right
speakers. The expected speaker setup is a 8Ωor 4Ωconfiguration (not to exceed
30W per side). Refer to the following diagram as a reference for connecting your
speakers.

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6Controls and Indicators
1. Speaker output connector (refer to Section 5.3.5)
2. Remote mute connector. Note that +5VDC to +10VDC is required to mute the amplifier.
3. Power connector (3.5mm): connect power adapter supplied with unit only. Be careful not to
insert this connector into the Mute connector location!
4. Input 2 level control.
5. Input 1 level control
6. Input 2 connectors (RCA phono)
7. Input 1 connector (3.5mm)
8. Power indicator LED illuminates when power is applied.
9. Clip indicator LED(left). If this LED is illuminated, reduce the input signal level.
10. Clip indicator LED (right). If this LED is illuminated, reduce the input signal level.
11. Signal present indicator LED illuminates when a signal is present at any input.
6.1 Sleep Mode
When no input signal is detected for a period of 5 minutes, the amplifier will enter sleep mode to reduce
power. The AV30MX-2’s Signal Sense Technology will power up the unit when a signal is subsequently
detected.
6.2 Level Controls
There are 2 level controls to adjust the level of the input signals. The level 1 control adjusts both the left
and right signal levels on input 1. Similarly, input level control 2 adjusts the left and right level of input 2
signals. Be certain to monitor the clip indicators when adjusting the input levels.
6.3 Remote Mute
The AV30MX-2 can be remotely muted (such as muting during a fire alarm). 5-12VDC should be applied to
the terminal block labeled “MUTE” on the rear of the AV30MX-2. Polarity should be observed when
connecting the triggering power source as the amplifier will not be muted if polarity is reversed.

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7Technical Specifications
Maximum output (30Hz –20kHz
Stereo
30W @ 4Ωor 8Ωper channel
Frequency response (+0, -3dB)
30Hz –20kHz
Bandwidth (±3dB)
30Hz –30kHz
THD + Noise
<0.1% @ 1W
Signal to noise ratio
>100dB
External mute
+5 to +12VDC (3.5mm connector)
Slew rate
30V/msec
Input sensitivity
0.5V (-6dBV)
Standard voltage gain
28 (26.5dB)
Input impedance (unbalanced)
10kΩ
Current draw
Sleep
Idle
1/8 power
5 mA
10 mA
150 mA
Class
D
Input connectors
3.5mm stereo; Dual RCA
Output connectors
5mm Euro block
Power supply
External in-line (Universal AC to +48VDC)
Cooling
Convection; no fans
Controls
2 independent input level controls; mute
LED indicators
Power; signal present; clip (2)
Construction
Aluminum enclosure
Dimensions
Height
Width
Depth
1.25 inches (3.2cm)
4.35 inches (11.1 cm)
3.2 inches (8.1 cm)
Weight
0.37 lbs. (0.16 kg)
Warranty
3 years
Stewart Audio reserves the right to change features and specifications without notice.

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8Troubleshooting
Problem: No power LED indicator
Procedure: Check that the amplifier is plugged into a live outlet. After you have ensured that it is not an AC
power issue, disconnect any speakers. If the amplifier turns on after a few seconds delay, then the problem
is in the output connection. Check wiring and speakers for short circuits.
Problem: No output on one or both channels; Power indicator is lit.
Procedure: Check that level controls are not turned down. C heck that input and output connections are
secure. Ensure signal present LED is flashing to denote a signal. If there is no signal detected check signal
source and that level controls are set high enough.
Problem: Amplifier overheats and/or shuts off.
Procedure: Review section 5.3.3 on proper cooling procedures. Check the signal lights on the rear of the
amplifier to see if the signal is overdriving (the signal light flashes red frequently). Overdriving the amplifier
for extended periods of time can cause a thermal shutdown.
Problem: Output sound is distorted or cracking.
Procedure: Check all cables for damage or loose connections and reduce the input signal level at the mixer
or preamp level. Replace the cables and loudspeakers temporarily to see if this resolves the problem.

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9Warranty Information
9.1 Warranty Summary
All Stewart Audio products and accessories, unless excluded in this summary, are covered by a 3-
year limited warranty on parts and labor from the data of purchase. In order to be eligible for
warranty repairs, the products and accessories must have been purchased through an authorized
Stewart Audio dealer and submitted by the original purchaser. This warranty is only valid in the
country in which the product was purchased.
9.2 Eligibility Requirements
Stewart Audio warrants against all malfunctions which come as a result of component or
manufacturer defect. The product is also covered from all failures which arise during the warranty
period (3 years from date of purchase) that are not a result of misuse. The following actions will
void your warranty:
The power cord or AC plug has been damaged through misuse.
The product has been exposed to moisture or extreme temperatures.
The product has been dropped, items have been dropped on the product, or the enclosure
has been damaged.
The product has been opened by the operator.
The product was improperly packaged when sending to the factory for repair, resulting in
damage.
Any of the precautions or instructions found in this manual were not followed.
Damages resulting to the product which are not covered under this warranty can be factory-
repaired at cost to the customer. Use the contact information below to initiate the repair process.
9.3 Non-warranty Repairs
An estimate for all non-warranty repairs will be provided to the customer once the unit has
been shipped to the factory. The customer is responsible to approve this estimate within 7
days. If the repairs are not approved within 14 days, Stewart Audio reserves the right to
consider the unit scrap and may discard it. Payment for non-warranty repairs must be
submitted to Stewart Audio before the product will be returned to the customer.
All returns to the factory for service must be accompanied by a Return Authorization (RA) number.
One can be obtained by contacting Stewart Audio at [phone] or via e-mail at
[email protected].
NOTE: Any defective products received without an RA number will be returned to sender at

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their expense.
If Stewart Audio is unable to contact the sender in 14 days, the merchandise will be considered
scrap and may be disposed of.
9.4 Shipment Instructions
If Stewart Audio requests that you ship the defective product back to their service center,
please refer to the guide below. To ensure prompt warranty service, be sure to follow all
instructions.
Return Authorization (RA) is required for product being sent to the factory for service.
See packing instructions in Section 10.2.
Ship the defective product using a method which provides for order tracking or order
confirmation. The service center is located at the following address:
Stewart Audio
14335 Cuesta Court Suite C
Sonora, CA 95370
Use a bold black marker and write the RA number on three sides of the box.
Record the RMA number for future reference. The RA number can be used to check the repair
status.
9.5 Packaging Instructions
Should Stewart Audio request that you ship your product to their service center, these instructions
must be followed in order to ensure safe delivery. If they are not followed, Stewart Audio assumes
no responsibility for damaged goods and/or accessories that are sent with your unit.
1. Please write the RA number on three sides of the box. Include the Stewart Audio RA
number inside the box and a brief description of the problem.
2. You will be advised during the RA process what accessories should be included with the
product (power supplies, connectors, cords, etc.). This is dependent on the failure
assessment.
3. When shipping your product, it is important that it has adequate protection. We
recommend you use the original packing material when returning the product for repair. If
you do not have the original box, see number 4.
4. If you provide your own shipping pack, use materials adequate to prevent damage during
transit. Make certain that the product is NOT free to move within the package, as this is
the most common cause of damage.
5. Securely seal the package with an adequate carton sealing tape.
6. Do not use light boxes or “peanuts”.
NOTE: Damage caused by poor packaging will not be covered under warranty.

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10 Accessories
The following amplifier accessories are available from Stewart Audio. All part numbers shown
are Stewart Audio part numbers.
Mounting Brackets
AV-POLE
Pole-mount bracket for AV Series amplifiers
AV-BRACKET
Universal mounting bracket for AV Series amplifiers