Audio Research REFERENCE PHONO 10 User manual

Owners Manual
H I G H D E F I N I T I O N ®
REFERENCE 10
Stereo Preamplifier

3
Contents
Illustrations: Audio Chassis 4
Illustrations: Power Supply Chassis 5
Preface 6
Warnings 6
Packaging 6
Installation of Vacuum Tubes 6
Front Panel Controls 7
Remote Contol only Functions 7
Connections 8
Installation Instructions 8
General Operating Procedure 8
Interactive Touch Screen Operation 9 - 10
Troubleshooting 10
Servicing 11
Cleaning 11
Disposal and Recycling Guidelines 11
Limited Warranty 11
Specications 12

4
Audio Chassis
RIGHT INPUTS
LEFT INPUTS
1
1
2
2
3
3
4
4
5
5
6
6
PROC
PROC
RECORD OUT
RECORD OUT
MAIN OUTPUTS
MAIN OUTPUTS
FROM POWER SUPPLY
CABLE "A"
FROM POWER SUPPLY
CABLE "B"
PLYMOUTH, MINNESOTA
MADE IN U.S.A.
REFERENCE 10
STEREO PREAMPLIFIER
RIGHT OUTPUTS
LEFT OUTPUTS
SERIAL
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
!
RS232
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

5
PLYMOUTH, MINNESOTA
MADE IN U.S.A.
REFERENCE 10
STEREO 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
~
REMOTE TRIGGER
+12V
6A FUSE
SLO-BLO
T4A (230V)
CAUTION
FOR CONTINUED PROTECTION AGAINST
FIRE HAZARD REPLACE FUSE ONLY
WITH SAME TYPE AND RATING
Power Supply Chassis

6
Preface
Please take time to carefully read and understand
the following instructions before you install or
attempt to operate your Audio Research Reference
10 preamplier. Becoming familiar with the product
and its correct operating procedures will help assure
you of maximum musical enjoyment and reliable
operation. The effort you invest now will be well
rewarded in the years ahead.
Warnings
1. To prevent re or shock hazard, do not expose
this product to rain or moisture.
2. This unit operates on voltages which can cause
serious injury or death. Do not operate with
covers removed. Any necessary servicing
should be carried out by your authorized Audio
Research dealer or other qualied electronics
technician.
3. The power cord supplied with this unit is safety-
tested and is equipped with a proper grounding
plug. If used normally, it will provide a safe
earth ground connection of the chassis. Defeat
of the grounding plug or use of a power cord
without a grounding plug, or any unauthorized
modication of the active circuitry or controls of
this unit, automatically voids warranty coverage,
and could cause injury or death.
4. For safe operation and protection against re
hazard, replace fuses only with those of the same
type and rating as those supplied with this unit.
Packaging
Save all packaging accompanying this product.
You have purchased a precision electronic
instrument, and it should be properly cartoned any
time shipment becomes necessary. It is very possible
that this unit could be damaged during shipment if
repackaged in cartoning other than that designed
for it. The original packaging materials help protect
your investment from unnecessary damage, delay
and added expense whenever shipment of this unit
is required.
DO NOT ATTEMPT TO OPERATE THIS EQUIPMENT
BEFORE INSTALLING THE NUMBERED VACUUM TUBES
IN THEIR RESPECTIVE SOCKETS.
Installation of Vacuum Tubes
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.
Do not attempt to install or remove any
vacuum tubes unless this unit is turned off
and disconnected from the A.C. power
outlet. Unit should be connected to the
A.C. outlet and turned on only after all vacuum
tubes have been installed and appropriate panels
have been replaced and fastened. See owner’s
manual for installation instructions.
Before replacing vacuum tubes, turn off unit,
disconnect from A.C. outlet and allow installed tubes
to cool before attempting to remove them. Hot
tubes may cause burns or other injury if not allowed
to cool before removal.
When removing or installing tubes, do not touch tube
socket contacts or other components as the circuit
may retain sufcient levels of voltage and current to
cause injury or death.
Contact your dealer or Audio Research Customer
Service (763-577-9700) if you have any questions
about installing or replacing vacuum tubes in this
unit.
V1V5
V7 V3
V2V6
V8 V4
TOP VIEW
AUDIO UNIT
g. 1
V9
TOP VIEW
POWER SUPPLY
UNIT V10
V11
V12
g. 2

7
Description of Controls
Front Panel Controls
The Reference 10 has one microprocessor-driven
rotary control and two buttons (Power and Mute).
Rotary control: Adjusts Volume (output level) up or
down for both L and R channels, and adjusts the
balance when the balance function is selected on
the main screen. Volume control is also selectable
via Vol UP and Vol DN buttons on the remote control.
Volume adjustment is indicated in the display window
by numeric digits on 0–103 scale.
Do not turn volume up beyond normal listening
levels when ‘mute’ is engaged to avoid unexpected
or possibly damaging sound levels. Reduce volume
level whenever changing input sources, even when
muted.
POWER ON/OFF: (left button beneath rotary control)
Supplies power from A.C. wall outlet to preamp;
indicated by active display window. Function also
on remote control.
For approximately 40 seconds after start up, ‘Mute’
appears in the display window and ashes until the
automatic muting cycle is completed. This also
occurs in the event of power interruption. Upon
completing the cycle, ‘Mute’ will cease ashing. The
preamp will remain muted until normal operation is
selected by pressing the ‘Mute’ button.
MUTE: (right button beneath rotary control) When
activated, electrically mutes all output of the
preamplier; 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 amplier and
speakers from unexpected signal pulses. When
deactivated, ‘Mute’ disappears from the display
window allowing normal operation. Function also
on remote control.
The Reference 10 also has automatic muting to help
protects 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, amplier
failure or speaker malfunction.
Remote Control only Functions
INPUT 1-6: Allows direct selection of each of the 6
inputs of the Reference 10.
PROCESSOR (Pass Thru): Selects external A-V (home
theater) processor as input source and controller of
volume level for R and L channels. Reference 10
provides Unity Gain when this input is selected.
When engaged, ‘Pass Thru’ will appear in the display,
and the gain is xed and not adjustable. The preamp
will also mute the input after ‘Pass Thru’ is engaged.
Before unmuting the ‘Pass Thru’ input,
be sure to turn the volume down on the
home theater processor. Never connect
a source with a xed level output (DVD
player, tuner, CD, etc.) to the ‘Pass Thru’ input or the
amplier(s) and speaker system could be damaged
when the Reference 10 is unmuted.
BAL/SE: Select as appropriate for each input.
For source components having balanced (XLR)
connections to the Reference 10, select BAL. For
single-ended (RCA) sources, select SE. Once
selected for an input source, the setting is memorized.
INVERT: Inverts absolute phase of the output signal.
MONO: Sums L and R input for mono output from
any source selected.
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.
BALANCE (BAL L/BAL R): Adjusts balance left or right.
Adjustment appears in display window as movable
marker on bar graph. Useful for compensating for
uneven speaker placement or imbalanced output
from a phono cartridge.
HOURS: When pressed, displays number of operating
hours vacuum tubes have been in service. WARNING:
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.

8
Connections
INPUT CONNECTORS: The Reference 10 provides
seven pairs of BAL/SE input connectors: 1, 2, 3, 4,
5, 6, and Processor. The BALANCED/SINGLE ENDED
selector (touch screen) or BAL/SE (remote) should be
selected to match the type of connection used (BAL
or SE) on each input.
Connect either the BAL or SE connectors for each
input. Never connect the BAL and SE connectors
simultaneously for each input.
OUTPUT CONNECTORS: Two pairs of BAL/SE main
outputs are provided.
RECORD OUTPUT: The BAL/SE tape outputs should
be connected to your recorder’s ‘Record’ or ‘Line’
inputs. These outputs provide a xed-level two-
channel signal (L, R) to your recorder from whichever
input is selected. The non-variable output level will
be the same as the output of the selected source.
It is possible to dub or copy from one recorder to
another by connecting the output of the source
recorder to an unused set of stereo inputs (e.g. 5 or
6). The signal will then be routed to the Record Out
connectors when that input source is selected.
RS-232 Connection: The RS-232 connection allows
for remote control via systems such as Creston or
other automation systems.
12V IN/OUT REMOTE START JACKS: The +12V DC
input/output jacks provide the ability to remotely
turn on and off other linked components such as
power ampliers having similar capabilities.
Installation Instructions
While the Reference 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:
1. Operate unit in upright and horizontal position,
prefer-ably on solid, non-metal shelving.
2. 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 10.
3. Do not place or operate your preamp on a soft
or irregular surface such as a rug. This will prevent
proper ventilation.
4. 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).
5. Ensure a minimum of 8-10” clearance above the
unit when placed on shelving.
General Operating Procedure
Start Up:
1. Secure all rear-panel connections between
Reference 10, power amplier(s) and input
sources.
2. 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.
3. 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 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.
4. Select input source, then BAL or SE as necessary.
Shut Down:
1. Activate ‘Mute’ function.
2. Set Volume level to 0.
3. Turn off power amplier(s).
4. Press Power switch to ‘off’.
5. Turn off input sources.
g. 3
g. 4

9
Interactive Touch Screen Operation
The Reference 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 all seven input options. Touch the
desired input to change (g. 6).
Balanced/SE, Stereo/Mono, Phase 0/180: To change
any of these functions, touch the word you wish to
affect and it will toggle between the two different
options for each category (g. 5).
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.
Balance: Touch the balance icon located in the top
right position of the screen (it appears as a double
ramp). The balance slider will appear beneath the
input name. Using the rotary control, adjust the
balance as needed to right or left channels. When
the balance is not at center, a ‘+’ sign will appear to
the right or left side of the balance icon indicating
to which channel the balance is offset. To re-center
balance, either use the rotary control to bring the
balance back to center or touch the inverted
triangle above the balance slider (g. 7).
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 10 (g. 8).
Input Names: Selecting Input Names will allow you to
customize the names of each input on the Reference
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.
g. 5
g. 6
g. 7
g. 8

10
Input Gain Offset: You may experience some
devices playing consistently louder than others (for
example, a CD player may always play louder than
a turntable). In this event, the Input Gain Offset can
be engaged to balance the overall volume between
the differing inputs, alleviating the need to adjust
the master volume when changing between inputs.
The Input Gain Offset screen is designed so you can
make adjustments easily to each input in real time.
For best results, play all devices connected to the
Reference 10 simultaneously, and from the Input
Gain Offset page, change inputs by touching the
input bar. If an input is louder or softer than another,
use the up and down arrows to adjust accordingly
(g 9).
Hours Meter: The Hours Meter displays the total
number of hours the Reference 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.
Foreground/Background Color: The Reference 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 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. 10).
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.
About: Touching the ‘About’ button displays a screen
with the current software version of the Reference
10. This information can be useful in the event the
Reference 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. Please note that resetting the Reference
10 back to factory settings does NOT reset the hours
meter.
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. 9
g. 10

11
Servicing
Because of its careful design and exacting standards
of manufacture, your Reference 10 should require no
routine maintenance. The remote control’s batteries
(AAA) should be replaced once a year.
CAUTION: Your Reference 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 10 are
quality tubes and with normal use should not need
to be changed for approximately 4,000 hours of use.
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.
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.
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.

12
Specications
FREQUENCY RESPONSE: +0 -3dB 0.1Hz to 200kHz at rated out-
put. (BALANCED, 200k ohms load.)
DISTORTION: Less than .006% at 2V RMS Balanced output.
GAIN: Main output (SE or BAL input): 12dB Balanced output,
6dB Single Ended output. Tape output: 0dB. (Processor
input: 0dB Balanced)
INPUT IMPEDANCE: 120K ohms Balanced, 60K ohms SE, Inputs
(7): 1, 2, 3, 4, 5, 6, PROCESSOR. (XLR and RCA connectors).
OUTPUT IMPEDANCE: 600 ohms Balanced, 300 ohms SE main
(2), 20K ohms minimum load and 2000pF maximum capac-
itance. Outputs (3): 2 main, 1 tape (XLR and RCA connec-
tors).
OUTPUT POLARITY: Non inverting.
MAXIMUM INPUT: 20V RMS maximum Balanced, (10V RMS SE).
RATED OUTPUTS: 2V RMS (1V RMS SE) into 200K ohm balanced
load (maximum balanced output capability is 30V RMS at
less than 0.5% THD at 1kHz).
CROSSTALK: -80dB or better at 1kHz.
CONTROLS: Volume (104 steps). Push Buttons: Power, Mute,
Interactive Touch Screen. Rear RS-232 control and IR input.
POWER SUPPLIES: Electronically regulated low and high voltage
supplies. Automatic 40 sec. warm-up/brown-out mute.
Line regulation better than .01%.
NOISE: 1.7uV RMS residual IHF weighted balanced equivalent
input noise with volume at 1 (109dB below 2V RMS output.)
TUBE COMPLEMENT: (8)-6H30P dual triodes, plus (2 each) 6550C
and 6H30P in power supply.
POWER REQUIREMENTS: 100-135VAC 60Hz (200-270VAC
50/60Hz) 220 watts. Standby: 2.2 watts.
DIMENSIONS: 19” (48 cm) W x 7” (17.8 cm) H (standard panel)
x15.5” (39.4 cm) D. Handles extend 1.5” (3.8 cm) forward
of the front panels.
WEIGHT: Audio Chassis: 23.6 lbs. (10.7 kg) Net; 33.3 lbs. (15.1
kg) Shipping. Power Supply Chassis: 37.65 lbs. (17.07 kg)
Net; 47.35 lbs. (21.48 kg) Shipping.
Specications subject to change without notice.
©2012 Audio Research Corporation.
This unit is RoHS compliant
3900 Annapolis Lane North
Plymouth, MN 55447
[phone]
www.audioresearch.com