Audio Research REFERENCE PHONO 10 User manual

User Guide
H I G H D E F I N I T I O N ®
REFERENCE
PHONO 10
Phono Preamplifier

2Contents
Preface 3
Illustrations
Audio Chassis 4
Power Supply Chassis 5
Warnings 6
Installation
Installation of Vacuum Tubes 7
In Your System 8
Connections 9
Operation
Power-Up Procedure 10
Front Panel Controls 11
Remote Control Only Controls 12
Interactive Touch Screen Operation 13 - 15
Troubleshooting 15
Maintenance
Servicing 16
Cleaning 16
Disposal and Recycling Guidelines 16
Limited Warranty 17
Specications 18

3
Preface
Thank you for selecting the Reference Phono 10 as
part of your music listening system. The engineers and
designers at Audio Research have spent countless hours
of listening and testing to create a preamplier of the
highest caliber for music reproduction. The Reference
Phono 10 has been designed to provide you many years
of playback.
Please take a few minutes to read through this guide
to help you better understand and optimize your new
preamplier. If you have any questions regarding the
operational functions, contact your dealer or distributor
for assistance.
Sit back and enjoy your new preamplier and the
enhancements it will bring to your system. The
Reference Phono 10 will bring new life to your record
collection.
Happy listening!

4Illustrations
POWER MUTE
PLYMOUTH, MINNESOTA
MADE IN U.S.A.
REFERENCE PHONO 10
STEREO PHONO PREAMPLIFIER
WARNING
TO PREVENT FIRE AND SHOCK HAZARD, DO NOT
EXPOSE THIS DEVICE TO RAIN OR MOISTURE.
UNIT MUST BE OPERATED IN A HORIZONTAL POSITION.
-DO NOT OPERATE WITH COVERS REMOVED-
UNIT CONTAINS VOLTAGES WHICH MAY BE HAZARDOUS.
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
!
SERIAL
FROM POWER SUPPLY
CABLE "A"
FROM POWER SUPPLY
CABLE "B"
RIGHT
RIGHT
INPUT 1
INPUT 2
LEFT
LEFT
TURNTABLE
GROUND
SINGLE
ENDED
BALANCED
SINGLE
ENDED
BALANCED
LEFT OUTPUT
RIGHT OUTPUT
RS232
Audio Chassis

5
Illustrations
Power Supply Chassis
PLYMOUTH, MINNESOTA
MADE IN U.S.A.
REFERENCE PHONO 10
STEREO PHONO PREAMPLIFIER
WARNING
TO PREVENT FIRE AND SHOCK HAZARD, DO NOT
EXPOSE THIS DEVICE TO RAIN OR MOISTURE.
UNIT MUST BE OPERATED IN A HORIZONTAL POSITION.
-DO NOT OPERATE WITH COVERS REMOVED-
UNIT CONTAINS VOLTAGES WHICH MAY BE HAZARDOUS.
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
!
VOLTS
SERIAL
TO AUDIO CHASSIS
CABLE "A"
TO AUDIO CHASSIS
CABLE "B"
235W MAX 50/60 HZ
~
6A FUSE
SLO-BLO
T4A (230V)
CAUTION
FOR CONTINUED PROTECTION AGAINST
FIRE HAZARD REPLACE FUSE ONLY
WITH SAME TYPE AND RATING
Remote
HOURS
INPUT 1
INPUT 2
RIAA
DSP DN
POWER
HI GAIN
REFERENCE
PHONO
DSP UP
50
100
200
500
1K
47K
DECCA
CUSTOM
LO GAIN
MUTE
COLUMBIA

6Warnings
To prevent re, or shock hazard, do not expose your Reference Phono 10
to rain or moisture.
This unit contains voltages which can cause serious injury or death. Do
not operate with cover removed. Refer servicing to your authorized Audio
Research dealer, service center or factory.
The detachable power cord on your Reference Phono 10 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 Reference Phono 10 chassis to provide
absolute protection from electrical shock.
For continued protection against re hazard, replace the fuse only with the
same type and rating as specied at the fuse holder.
The appliance coupler at the rear of this unit must be accessible for
emergency power disconnect.
A note about packaging...
Save all packaging in a dry place away from re hazard. Your Reference
Phono 10 preamplier 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 Reference Phono 10 from unnecessary damage or delay.

7
Installation
Installation of Vacuum Tubes
Before operating the Reference Phono 10...
This unit has been shipped with the vacuum tubes installed in protective
foam in a separate box packed inside the shipping carton. Remove the
tubes carefully from the protective foam. Using a phillips-head screwdriver
to loosen the fastening screws, remove the top cover and set aside.
After removing the top cover and the vacuum tubes packed in protective
foam, see the accompanying illustrated sheet (g. 1 + 2) for instructions
on installing the tubes for your Reference 10 in their proper locations in the
power supply and audio chassis. Note that the numbers written on each
tube correspond to a ‘V’ number printed on the circuit board next to each
tube socket. Insert each tube rmly, carefully aligning the tube pins with the
corresponding socket holes.
V1V5
V7 V3
V2V6
V8 V4
TOP VIEW
AUDIO UNIT
L
R
g. 1
L
R
V9
TOP VIEW
POWER
SUPPLY
UNIT
V10
V11
V12
g. 2

8Installation
In your System
While the Reference Phono 10 does not dissipate an unusual amount of
heat, it is important that it be provided with reasonable airow to assure
long, trouble-free operation. In addition, the following installation guidelines
will help insure maximum sonic performance as well as reliable service:
Operate unit in upright and horizontal position, prefer-ably on solid, non-
metal shelving.
Do not stack the preamp on top of a power amplier: not only could this
cause overheating, but hum may be introduced into the preamp from the
proximity of the amplier’s power transformer.
Do not stack components or other objects directly on top of the Reference
Phono 10.
Do not place or operate your preamp on a soft or irregular surface such as
a rug. This will prevent proper ventilation.
Do not operate your preamp without the top and bottom covers installed.
These are required both for safety as well as shielding from interference
(except in service operations by qualied personnel).
Ensure a minimum of 8-10” clearance above the unit when placed on
shelving.

9
Connections
Input Connections
The Reference Phono 10 offers two sets of RCA input connectors, for
connecting multiple turntable/tonearm cables. There is a ground terminal
connection adjacent to the RCA input connectors to allow grounding of the
turntable(s).
Output Connections
There is one set of BAL and one set of RCA output connectors for connecting
to line inputs (Direct, Aux, Phono, Tuner, etc.) of your linestage/preamplier.
All input/output connectors are gold plated and connect ‘ground’ before
‘hot’. On disconnect, ‘hot’ is disconnected rst.
Note: A ‘passive’ line stage is not recommended for use with the Reference
Phono 10 as it may not provide the gain necessary to amplify the output of
the Reference Phono 10 to adequate levels to the power amplier.
It is recommended that all connections be made to the Reference Phono
10 with the power turned ‘off’.

10 Operation
Power-Up Procedure
Secure all rear-panel connections between Reference Phono 10 and the
preamplier. Connect umbilical cables between the Reference Phono 10
Audio and power supply chassis. Twist outer ring to secure.
Plug three-prong power cord from rear of chassis into grounded A.C. wall
outlet. The Power switch defaults to ’off’ when the unit is plugged into a
power receptacle.
Press power switch (either remote or front panel). The screen will initially
display ‘Now Loading’ for a few seconds, after which it will display the Audio
Research logo followed by ‘Reference Phono 10’ (g. 3 + 4). The main
display screen will then appear on the screen, and ‘MUTE’ will be ashing.
Once ‘MUTE’ becomes solid, depress the front panel MUTE button (right
button) or touch the word ‘MUTE’ on the screen to initiate normal operation.
Select input source, then make any other necessary adjustments.
Shut-Down
• Activate ‘Mute’ function.
• Turn off power amplier(s).
• Turn off preamplier.
• Press Reference Phono 10 Power switch to ‘off’.
g. 3 g. 4

11
Front Panel Controls
The front panel of the audio chassis of the Reference Phono 10 features
two buttons, and an interactive touch screen.
Power On/Off: (left button) Supplies power from A.C. wall outlet to preamp;
indicated by active display window.
The Reference Phono 10 requires approximately 40 seconds to warm up;
this time is required to stabilize the power supply. See ‘Power-Up Procedure’
on the adjacent page for details. The same cycle also occurs in the event
of a power interruption.
Mute: (right button) When activated, electrically mutes all output of the
phono stage; indicated by ‘Mute’ in display window. This control should be
activated before switching inputs, changing connections or shutting down
your audio system to help protect your components and speakers from
unexpected signal pulses. When deactivated, ‘Mute’ disappears from the
display window allowing normal operation.
The Reference Phono 10 also has automatic muting to help protect system
components during A.C. power interruptions or low line voltage. When
sensing these conditions, the preamp automatically goes into ‘Mute’ and
disables all outputs. The 40-second warm-up timer will restart and ‘Mute’
will ash in the display window when normal power conditions have been
restored.
Note that automatic muting is only designed to protect against power line
interruptions or severe voltage drop. It will not mute in the event of subsonic
transmissions from a faulty input source, component failure or speaker
malfunction.
Operation

12 Operation
Remote Only Functions
Load (50, 100, 200, 500, 1K, 47K, Custom): Select the appropriate load to
match the resistance of your phono cartridge. If not set with a specic value
when manufactured, the default value for the Custom setting is 47K (note
that the value for the custom setting can be adjusted by Audio Research or
an authorized Audio Research service center).
Input 1/Input 2: Selects the input for playback.
Lo Gain/Hi Gain: Selects the amount of gain for playback. Low Gain offers
51 dB of gain, and is intended for cartidges with high output, usually above
0.5 mV. High Gain offers 74 dB of gain is intended for cartridges below
0.5mV.
Display Down/Display Up (DSP DN/DSP UP): Decreases/increases
display intensity, offering 6 levels of brightness and display ‘off’. In display
‘off’ mode the display will illuminate for 10 seconds when any button (except
Power on/off) is selected, allowing for control function navigation.
Equalization Curves (RIAA, COLUMBIA, DECCA): Select between
different equalization curves for playback. RIAA equaliztion, introduced
in 1954, is the standard with which most records have been produced.
During the early era of stereo records, both Columbia and Decca Studios
used curves which varied from the RIAA curve. Check the record sleeve for
information which may indicate whether your record was recorded using
the RIAA curve.
Hours: When pressed, displays number of hours vacuum tubes have been
in service.
Note: After replacing tubes, this function should be reset to ‘0’. See further
instructions under ‘Hours Meter’ in the section ‘Interactive Touch Screen
Operation’ for details.

13
Operation
Interactive Touch Screen Operation
The Reference Phono 10 has been designed with a 7” interactive touch
screen for reliable and easy usage. The interface is programmed so that
the desired item for change simply needs to be touched to either toggle
between functions, or bring up a secondary menu for function selection.
Input Selection: To change inputs, touch the currently displayed input
name on the screen. The input bar will appear, listing both input options.
Touch the desired input to change (g. 5).
Equalization, Load, Gain: To change any of these functions, touch the
word you wish to affect and it will toggle between the different options for
each category (g. 6).
Mute/Operate: Toggle mute on and off by touching the screen where
‘MUTE’ or ‘OPERATE’ is displayed. You may also use the right button
beneath the rotary control to toggle between mute and operate.
g. 5
g. 6

14 Operation
SETTINGS MENU
Touching the settings icon located in the bottom right of the screen (it
appears as a gear) brings you to a submenu with different options related
to the setup and functionality of the Reference Phono 10 (g. 7).
Input Names: Selecting Input Names will allow you to customize the names
of each input on the Reference Phono 10. Once selected, the input bar will
appear at the top of the screen with an alphanumeric keyboard below it. To
change the name of any input, simply touch the input until it is highlighted
and type in the new name. When input naming is complete, select ‘DONE’
to go back to the settings menu.
Tube Hours: The Hours Meter displays the total number of hours the
Reference Phono 10 has been running. This is useful to gauge tube life
and prepare for eventual replacement. The hours meter may be reset after
the tubes have been changed by touching the ‘Reset’ button located in the
bottom right of the screen.
About: Touching the ‘About’ button displays a screen with the current
software version of the Reference Phono 10. This information can be useful
in the event the Reference Phono 10 needs troubleshooting. In the bottom
right of the About screen is a ‘Defaults’ button. Selecting the defaults
button will return all settings in the Reference 10 as they were shipped from
the factory.
Note: Resetting the Reference Phono 10 back to factory settings does NOT
reset the hours meter.
g. 7

15
Operation
Foreground/Background Color: The Reference Phono 10 has ten color
options for both screen background and text. Selecting either one of these
options from the settings menu will allow you choose a new color to
customize the display on your Reference Phono 10. Please note that the
currently selected color is not displayed in the choices shown, nor do you
have the option to choose the same color for both the background and
foreground (g. 8).
Display Intensity: Display Intensity adjusts the backlight for the screen
and its overall brightness. There are six levels plus ‘off’, with ‘6’ being the
brightest. When ‘off’ is selected, the display will remain on for 8 seconds
and then shut off. To return illumination to the screen, simply touch it or
press a button on the remote. When adjusting the brightness, the words
‘Display Intensity’ will reect the overall setting seleted. The display intensity
can also be adjusted from the remote using the ‘DSP UP’ and ‘DSP DN’
buttons.
Troubleshooting
It is possible for a static discharge to temporarily disable the microprocessor
that allows the controls to function. If this should occur, depress the ‘Mute’
button, then turn off the preamp and unplug the preamp from the A.C.
receptacle for 60 seconds. Reconnect the A.C. plug and turn the preamp
back on, along with other components. The controls should resume normal
operation. If the problem persists, contact your dealer or Audio Research
Customer Service at 763-577-9700.
g. 8

16 Maintenance
Servicing
CAUTION: Your Reference Phono 10 contains sufcient levels of voltage
and current to be lethal. Do not tamper with a component or part inside the
unit. Refer any needed service to your authorized Audio Research dealer or
other qualied technician.
The vacuum tubes inside your Reference Phono 10 are quality tubes and
with normal use should offer approximately 2,000 hours of use for the 6550
and 4,000 hours for the 6H30. Replacement tubes should be of equivalent
quality and are available from Audio Research. Note that tube numbers
(V1, V2 etc.) match printed numbers next to tube sockets on circuit board.
Should service be necessary, please contact your Audio Research dealer,
or Audio Research Customer Service at 763-577-9700 or service@
audioresearch.com.
Cleaning
To maintain the new appearance of this unit, occasionally wipe the front
panel and top cover with a soft, damp (not wet) cloth to remove dust.
A mild, non-alkaline soap solution may be used to remove ngerprints or
similar smudges. Cleaners containing abrasives should not be used as they
will damage the anodized nish of the front panel. A small, soft paintbrush
is effective in removing dust from bevels, the recessed nameplate and other
features of the front panel.
Disposal and Recycling Guidelines
To dispose of this electronic product, do not place in landll. In accordance
with the European Union Waste Electrical and Electronic Equipment (WEEE)
directive effective August 2005, this product may contain regulated materials
which upon disposal require special reuse and recycling processing.
Please contact your dealer or importing distributor for instructions on
proper disposal of this product in your country. Or, contact Audio Research
Corporation (763-577-9700) for the name of your importing distributor and
how to contact them.
Packing and shipping materials may be disposed of in a normal manner.

17
Limited Warranty
Audio Research Corporation products are covered by a 3-Year Limited
Warranty, or a 90-Day Limited Warranty (vacuum tubes). This Limited
Warranty initiates from the date of purchase, and is limited to the original
purchaser, or in the case of demonstration equipment, limited to the balance
of warranty remaining after original shipment to the retailer or importer.
In the United States, the specic terms, conditions and remedies for fulllment
of this Limited Warranty are listed on the warranty card accompanying the
product in its shipping carton, or may be obtained from the authorized retailer
or from the Audio Research Customer Service Department. Outside the
United States, the authorized importing retailer or distributor has accepted
the responsibility for warranty of Audio Research products sold by them.
The specic terms and remedies for fulllment of the Limited Warranty
may vary from country to country. Warranty service should normally be
obtained from the importing retailer or distributor from whom the product
was purchased.
In the unlikely event that technical service beyond the ability of the importer
is required, Audio Research will fulll the terms and conditions of the Limited
Warranty. Such product must be returned at the purchaser’s expense to
the Audio Research factory, along with a photocopy of the dated purchase
receipt for the product, a written description of the problem(s) encountered,
and any information necessary for return shipment. The cost of return
shipment is the responsibility of the purchaser.

18
Frequency Response: ± .2dB of RIAA, 10Hz to 60kHz; 3dB points below 0.3Hz and above 300kHz.
Distortion: Less than .002% at 1.0V RMS 1kHz output.
Gain: Selectable 51dB (Low), 74dB (High) at1kHz BAL; 45dB (Low), 68dB (High) at1kHz SE. (MC & MM compati-
ble).
Buttons: Front (2) Power, Mute
Input Impedance: 47K ohms and 100pF SE. Selectable loads: 1000, 500, 200, 100, 50 ohms and Custom.
Phono Equalization: (Selectable) RIAA, Columbia, Decca.
Output Polarity: Non inverting.
Output Impedance: 200 ohms SE, 400 ohms balanced. Recommended load 50K-100K ohms and 100pF. (10K
ohms minimum and 2000pF maximum.)
Maximum Input: 250mV RMS at 1kHz (680 mV RMS at10kHz).
Rated Outputs: 0.5V RMS 10Hz to 20kHz, 100K ohm load (output capability is 80V RMS BAL output at 1/2%
THD at1kHz, 40V SE.)
Power Supplies: Electronically regulated low and high voltage supplies. Automatic 40 sec. warm-up/brown-out
mute. Line regulation better than .01%.
Noise: 0.22uV equivalent input noise, IHF weighted, shorted(Low Gain) input (73 dB below 1mV 1kHz input).
0.055uV equivalent input noise (High Gain) (65dB below 0.1mV 1kHz input)
Tube Complement: (8)-6H30P dual triodes, plus (2 each) 6550C and 6H30P in power supply.
Power Requirements: 100-135VAC 60Hz (200-270VAC 50/60Hz) 235 watts maximum. Standby: 0.8 watts.
Dimensions: Width 19” (48 cm)
Height 7” (17.8 cm) (standard rack panel)
Depth 15.5” (39.4 cm)
Handles extend 1.5” (3.8 cm) forward of the front panels.
Weight: Audio Chassis: 22 lbs. (10 kg) Net; 34 lbs. (15.5 kg) Shipping.
Power Supply Chassis: 35 lbs. (15.9 kg) Net; 43 lbs. (19.5 kg) Shipping.
This unit is RoHS compliant
Specications
H I G H D E F I N I T I O N ®
Specications subject to change without notice.
©2013 Audio Research Corporation.
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