Audio Research I/50 User manual
You.Thank
Thank you for choosing the I/50 Integrated to be a part of your music
listening system. Since 1970, Audio Research has been creating some
of the world’s finest audio equipment. Each piece is handcrafted in
Minnesota, and has been designed to provide many years of listening enjoyment.
We understand you are eager to begin listening; however, please
take a few minutes to read through this guide for useful information
concerning the operation of your new integrated amplifier. Once
installed, please allow an appropriate break-in period to fully appreciate
the sonic performance this integrated will provide to your system.
After reading the user guide, if you have any further questions regarding
your I/50, contact your dealer or Audio Research customer service - they
will be happy to help you make the most of your new component.
Happy Listening!
CONTENTS Safety
Warnings
Installation
Connections
Operation
Maintenance
Warranty
Specifications
Vacuum Tube Installation
Before operating the I/50
In your system
A note about vacuum tubes
Back Panel Connections
Input Connectors
Output Connectors
Headphone
Impedance Matching
Phono Module
AC Power Connection
Top Panel Controls
Remote Functions
Start Up
Shut Down
Break In
Rotary Control Knobs
Remote Control Functions
Phono Module
DAC Module
Vacuum Tubes
Servicing
Cleaning
5
7
8
9
9
10
12
13
13
13
14
14
15
16
16
17
17
17
18
18
19
19
20
20
21
22
23
5
SAFETY
The lightning flash with arrowhead symbol with 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 sucient 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 (service) instructions in the literature accompanying the product.
The 3 wavy lines symbol within an equilateral triangle is intended to alert the user to the presence of a hot surface on
the exterior case of the product.
• Read these instructions.
• Keep these instructions.
• Heed all warnings.
• Follow all instructions.
• Do not use this apparatus near water.
• Clean only with a soft, damp (not wet) cloth.
• Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
• Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce
heat.
• Do not defeat the purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than the other. A
grounding-type plug has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the
provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.
6
SAFETY
• Warning: The apparatus shall be connected to a mains socket outlet with a protective earthing connection.
• Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit
from the apparatus.
• Only use attachments/accessories specified by the manufacturer.
• Unplug this apparatus during lightning storms or when unused for long periods of time.
• 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 normally, or has been dropped.
• WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPARATUS TO RAIN OR MOISTURE.
• DO NOT EXPOSE THIS APARATUS TO DRIPPING OR SPLASHING AND THAT NO OBJECTS FILLED WITH LIQUIDS, SUCH AS VASES,
SHOULD NOT BE PLACED ON THE APPARATUS.
• TO COMPLETELY DISCONNECT THIS APPARATUS FROM THE AC MAINS, DISCONNECT THE POWER SUPPLY CORD FROM THE AC
RECEPTACLE.
• THE MAINS PLUG OF THE POWER SUPPLY CORD SHALL REMAIN READILY ACCESSIBLE.
• The user-replaceable rear panel fuse of the I/50 shall only be replaced with a fuse of the correct breaking capacity and voltage rating as
specified below and on the rear panel of the amplifier.
100-127V T5AL250V MDQ (ARC part 34600501)
220-240V T3.15AL250V (ARC part 34600301)
• Speaker terminal banana jacks are plugged/capped for units sold in countries where this is required due to power cord plug pin shape.
7
To prevent fire, or shock hazard, do not expose your I/50 to rain or moisture.
Do not place objects containing liquids on top of this unit.
This unit contains voltages which can cause serious injury or death. Do not operate with covers removed. Refer servicing to your autho-
rized Audio Research dealer or other qualified personnel.
The detachable power cord on your I/50 is equipped with a heavy gauge, 3-conductor cable and a standard three-prong grounding plug.
For absolute protection, do not defeat the ground power plug. This provides power line grounding of the I/50 chassis to provide absolute
protection from electrical shock.
The appliance coupler (A.C. power connector) at the rear of this unit must be accessible for emergency power disconnect.
The power button on the front of this unit, when o, does not disconnect all power from this unit. This unit is in sleep mode when not on.
For continued protection against fire hazard, replace the fuse only with the same type and rating as specified at the fuse holder (see page
19 for fuse information).
This unit is RoHS compliant.
A note about packaging...
Save all packaging in a dry place away from fire hazard. Your I/50 amplifier is a precision electronic instrument and should be properly
cartoned any time shipment is made. You may not have occasion to return your unit to the factory for service, but if that should prove
necessary, or other occasion requiring shipment occurs, the original packaging will protect your I/50 from unnecessary damage or delay.
WARNINGS
8
INSTALLATION
V1 - V4
6550WE
V5 - V7
6922
VACUUM TUBE INSTALLATION
LexieTube®
Display
9
INSTALLATION
Before operating the I/50
Your I/50 amplifier is shipped with the vacuum tubes packed in a separate foam-lined carton. These must be unpacked and installed
before you attempt to operate the amplifier. Included are three 6922 tubes for the input and driver stages, and a matched pair of
6550WE for the amplification output stage. Proceed according to the following instructions.
Remove tube cover. Carefully remove each vacuum tube from its protective foam and match its location ‘V’ number (written on the base
of the tube) to the ‘V’ number printed next to each socket. Firmly seat each tube in its matching socket, taking care to ‘key’ the tube pins
to the socket holes. Retain the tube carton with other packing materials for possible future use.
Refasten tube cover on the I/50.
In your system
To ensure normal component life and safe operation this unit must be operated only in an upright position. Adequate airflow and proper
cooling can occur only if there is no restriction above and behind the unit and on either side.
The special non-marring elastomer feet provide adequate spacing and stability only on a smooth, hard surface, and also assist to isolate
the amplifier from spurious vibrations. For upright stability and best performance, never operate the unit while it is sitting on a soft surface
such as a rug or carpet.
Due to its weight (40 lbs/18.1kg), this amplifier must be supported on a surface specifically rated for such a load. Check with the
manufacturer of your support system to be sure it is rated to handle this weight.
10
If the unit is to be operated in an enclosure such as an equipment rack, make certain that adequate airflow above and to each side of
the unit is provided. Audio Research recommends a minimum of 6-8 inches (15-20 cm) of clearance above the I/50 to maintain proper
ambient operating temperature. It is not recommended to operate the I/50 in an enclosed cabinet.
The ‘ambient’ operating temperature should never exceed 120° F or 49° C. Improper installation will cause premature tube failure and will
aect your warranty, as well as the service life of the unit.
It is normal for a vacuum tube amplifier to run quite warm, and if used for prolonged periods, hot to the touch. All components within are,
however, operated at safe, conservative levels and will not be improperly aected thereby, providing the requirements outlined above
are adhered to.
A Note about Vacuum Tubes
The vacuum tubes in your I/50 have been burned in, tested and electrically matched to provide the best performance and reliability of
your amplifier. That said, vacuum tubes must be replaced from time to time. The 6922 tubes in the I/50 should have an expected life of
approximately 4,000 hours, while the 6550WE tube in the power amplifier should have a life expectancy of approximately 2,000 hours.
These life expectancies are only approximate. The damper rings on the 6922 tubes may be reused.
Important: When replacing vacuum tubes, please seek assistance from your dealer or local service shop. The bias will need to be
readjusted for the new set of installed tubes.
INSTALLATION
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