JEFF ROWLAND CONCERTO User manual

OWNER’S MANUAL CONCERTO STEREO PREamPlifiER

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
TABLE OF CONTENTS
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER
Introduction 2
Product Features 3
Package Contents 4
Initial Inspection 5
Maintenance & Cleaning 6-7
Protection Systems 7
Installation, Use & Care 8-9
Remote Transmitter Operation 10-11
Front Panel Functions 12-13
Rear Panel Signal Connections 14-15
Rear Panel Power Connections 16-17
Specications 18
Dimensions 19
Optional Adjustments 20-25

PO BOX 7231, COLORADO SPRINGS, COLORADO 80933 USA E-mAIL: [e-mail] www.jEffROwLAND.COm TELEPHONE [phone]
2
If you have any additional questions
regarding the installation or operation
of the CONCERTO Stereo Preamplifier,
please contact your authorized Jeff
Rowland Design Group dealer or check
the Jeff Rowland Design Group web site
at www.jeffrowland.com.
Enjoy the music!
Jeff Rowland
President,
Jeff Rowland Design Group
CONCERTO
Stereo Preamplifier. A thorough
understanding of the operational features will
allow you to gain the maximum performance
and ease of use for which this amplifier was
designed. Please note that your CONCERTO
Stereo Preamplifier serial number begins
with the letters “PA.” This serial number is
located on the rear panel of the chassis.
Please include this number with any corre-
spondence regarding your CONCERTO
Stereo Preamplifier. It has been my joy to
create an audio component of enduring value
that reflects the highest ideals of musical and
artistic expression. It is my hope that these
qualities will enrich your experience and
pride of ownership.
Welcome to the Jeff Rowland Design
Group “family” and congratulations on your
purchase of what is unquestionably one
of the world’s finest preamplifiers. With its
combination of features such as numerous
function control and interconnect possi-
bilities, system configuration flexibility,
precision electronic circuitry, exceptional
efficiency, and accurately machined chassis
components throughout, your CONCERTO
Stereo Preamplifier will offer you many years
of musically satisfying enjoyment.
Please take a few minutes to read the
remainder of this Owner’s Manual before
proceeding with the installation of the
INTRODUCTION
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
3
• Two pairs XLR input connectors for
balanced system congurations.
• Three pairs RCA input connectors for
unbalanced system congurations.
• Two pairs of parallel, high-current,
balanced line level preamplier outputs
to allow driving of external ampliers,
subwoofers, zones, etc.
• Fully-balanced transformer-coupled
inputs provide
universal compatibility
with other
components and eliminate
ground loop noise and EMI.
• Fully-balanced circuit topology
implemented on all inputs and outputs.
• Bypass function allows for transpar-
ent use in combination audio/home
theater systems.
• Regulated, high-current, linear power
supply provides stable operating volt-
age with the lowest possible noise and
distortion artifacts under all operating
and line conditions.
• Low power consumption permits
constant power-up operation to
eliminate warm-up time.
• Optical encoder type volume control
maintains quiet, trouble-free perfor-
mance and accuracy over the entire
lifetime of the product.
• Dual range volume control allows
large volume level changes when
knob is rotated abruptly, yet allows
small, precise volume level changes
when knob is rotated slowly.
• Six function, hand-held infrared
remote transmitter.
• Ultra-low resonance, structurally
rigid chassis, precision-machined
from a solid block of aircraft grade
6061-T6 aluminum.
• Optional plug-in phono cards
(installed internally) convert Line
Input 2 to high performance phono
inputs. Three gain and loading
options can accommodate moving
magnet (MM), moving coil (MC)
cartridge types and high output
moving coil cartridge types.
PRODUCT FEATURES
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER

PO BOX 7231, COLORADO SPRINGS, COLORADO 80933 USA E-mAIL: [e-mail] www.jEffROwLAND.COm TELEPHONE [phone]
4
PACKAGE CONTENTS
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER
WARRANTY REGISTRATION
WARRANTY CARD
INPUT
MUTE
BAL L
BAL R
VOL
VOL
AC POWER CABLE
REMOTE TRANSMITTER OWNER’S MANUAL
CONCERTO STEREO PREAMPLIFIER

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
5
Inspect the shipping container for damage. If any portion of the shipping container, packing material,
preamplifier, or accessories are damaged or missing, notify your dealer and the shipper (if a claim
is to be made) immediately.
NOTE: Many shippers require notication and inspection within 24 hours of delivery to determine the nature of damages incurred.
Your CONCERTO Stereo Preamplifier has undergone extensive performance evaluations, listening
tests, quality control inspections, and a minimum 72 hour burn-in period prior to shipment and should
therefore be in perfect operating condition upon delivery. If the preamplifier does not operate correctly,
please notify your dealer immediately.
We strongly suggest that you save all of the packing materials. If the preamplifier is returned to your
dealer or JRDG, the original packing materials must be used for shipment to avoid possible damage.
Neither JRDG nor the shipper can be held responsible for damages incurred during transit if the
original factory packing is not used. All factory returns require that JRDG issue a Return Authorization
(RA) number prior to shipment.
INITIAL INSPECTION
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER

PO BOX 7231, COLORADO SPRINGS, COLORADO 80933 USA E-mAIL: [e-mail] www.jEffROwLAND.COm TELEPHONE [phone]
6
All JRDG products are designed to provide a lifetime of enjoyment
and listening pleasure. The CONCERTO Stereo Preamplifier is uniquely
constructed from a solid block of precision-machined aluminum.
It’s chassis is sealed to prevent dust from
entering the interior of
the chassis and thus should never need interior cleaning during the
lifetime of the product. All internal circuitry is maintenance-free such
that no adjustments of any kind are necessary over the lifetime of
the product. If the amplifier is ever in need of service, updating, or
upgrading, it should only be returned to an authorized repair facility
or technician for servicing.
The front panel of the unit is precision-machined in a unique process
that incorporates a diamond tipped cutting tool. This process was refined
over many years to produce an attractive and unique appearance.
Because the surface is not finished in the typical fashion of most
audio and video equipment, there are a few rules that must be kept
in mind when cleaning the equipment.
• Please allow the front panel, which is coated with an automotive-grade polyure-
thane nish, to cure for 6 months before attempting to clean it.
This will prevent
small scratches from marring the surface before the surface coating has had a
chance to harden completely.
• The front panel of the unit should never be cleaned with anything other than a very
soft cotton cloth and plain water or ne oil-based furniture polish. Because of the
ne nish of the front panel, use of any other cleaning agent may permanently
scratch the nish.
• The top cover, sides and bottom are protected by a durable black anodized nish
and can be cleaned with a soft cotton cloth (such as an optical lens cleaning cloth
or ne furniture polishing rag) dampened with plain water. Water should be applied
directly to the cloth and not the chassis. A very mild plastic or glass cleaner that
does not contain ammonia may also be used. If a mark has been left on the
chassis,
do not use any type of abrasive or chemical cleaner to remove the mark.
Maintenance & cleaning
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
7
Protection SyStemS
The CONCERTO Stereo Preamplifier is equipped with internal fuses
for protection against excessive AC current draw; however, since no
protection circuitry or system can completely protect a product from
every electrical hazard, certain precautions should be observed. In the
event of severe voltage hazards such as lightning or when the pream-
plifier will not be used for extended periods of time, the preamplifier
should be unplugged from the AC mains to avoid potential damage to
the internal circuitry. All other audio/video system components should
also be disconnected from AC mains power as hazardous voltages
can easily travel throughout an interconnected system.
If you have any questions about the care or cleaning of your
CONCERTO Stereo Preamplifier, please contact your dealer or the
JRDG factory before attempting to clean the chassis. The use of a
cleanser or abrasive to clean the chassis that has not been approved
by the factory will almost certainly damage the finish and will not be
covered under warranty.
NOTE: Cleaner/polish should be applied directly to the cloth and not the chassis.

PO BOX 7231, COLORADO SPRINGS, COLORADO 80933 USA E-mAIL: [e-mail] www.jEffROwLAND.COm TELEPHONE [phone]
8
Locate the preamplifier as close as possible to its final installation point. Allow access to the rear
panel for making connections. Due to it’s design, the CONCERTO Stereo Preamplifier is energy
efficient, eliminating the need for heatsinks or forced-air cooling. As a result, the CONCERTO
Stereo Preamplifier can be housed in a cabinet or custom enclosure with no fear of overheating.
The efficient and compact design of the CONCERTO allows it to be installed in any number of
music, film, and surround sound systems. For connection instructions for a typical two-channel
stereo system, please see page 15 of this manual. For instructions regarding the use of the BYPASS
INPUTS for surround sound or home theater system use, please see page 15 of this manual.
The main chassis of the CONCERTO is precision-machined out of a solid block of aluminum
to create as rigid an enclosure as possible, impervious to lateral and torsional forces. The
preamplifier is particularly non-resonant; however, various damping and resonance control
accessories may be used to yield greater audio performance in some audio systems.
RISK OF ELECTRICAL SHOCK!
WARNING : Do not attempt to access the interior of the CONCERTO STEREO PREAMPLIFIER by removing the bottom
cover. Doing so will void your warranty and could expose you to dangerous, potentially lethal electrical voltages.
InstallatIon, Use & care
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
9
The JRDG CONCERTO Stereo
Preamplifier has been designed
to operate at the highest level of
efficiency and performance in
any normal
operating situation;
however, there are a few impor-
tant use and care principles
that must
be kept in mind when
operating the preamplifier:
• Do not expose the preamplier to
rain, moisture, or excessively
damp conditions.
• Make sure that the voltage indicated
on the rear panel matches the mains
voltage in your area.
• The CONCERTO Stereo Preamplier
must not be modied in any way,
other than according to ofcial
service bulletins from JRDG.
Otherwise, the factory warranty
will be immediately voided.
• Be sure the preamplier is muted
(red front panel indicator light on)
before connecting or disconnecting
any interconnect cables.
• When operating the CONCERTO ,
a
properly grounded AC receptacle
should be used. A potential shock
hazard may result if the supplied
3-wire, grounded AC cable ground
terminal is defeated or lifted or
the unit is connected to a 2-wire
ungrounded AC outlet.
• The CONCERTO is designed to per-
form
optimally with no adjustments
or
maintenance for the lifetime of the
product. Do not attempt to open the
bottom cover of the preamplier and
refer all service issues to qualied
personnel. The voltages inside the
CONCERTO can be hazardous.
• Because of the energy efciency
of the CONCERTO, there is no need
to unplug the unit when not in use;
however, the preamplier can be
muted if desired.

PO BOX 7231, COLORADO SPRINGS, COLORADO 80933 USA E-mAIL: [e-mail] www.jEffROwLAND.COm TELEPHONE [phone]
10
INPUT
MUTE
BAL L
BAL R
VOL
VOL
1
2
3
4
6
5
The CONCERTO Stereo
Preamplifier is equipped with a
wireless, infrared (IR) remote
transmitter, allowing convenient
wireless control of the most
commonly used functions from
the listening position. An expla-
nation of these functions and
battery installation follows.
NOTE: Placing the preamplier in
extreme
ly high ambient light condi-
tions may
cause erratic remote control
operation. The IR sensor, located within
the volume level display,
must not be
exposed to direct
sunlight or spotlights.
(3) VOLUME : The VOLUME
UP
button will increase the output
level of the preamplifier in 0.5 dB
increments. Holding this button
down will cause the volume level
to continuously increase until the
button is released or until 99.5 is
displayed on the volume display.
(4) VOLUME : The VOLUME
DOWN button will decrease the
output level of the preamplifier
in 0.5 dB increments. Holding
this button down will cause the
volume level to continuously
decrease until the button is
released or until 00.0 is displayed
on the volume display.
(1) INPUT SELECT: This button
will select the desired input, the
input number corresponding to
the numbering of the inputs on
the rear panel. Each press of
this button will scroll to the next
successive input. Once Input 5
has been reached, the next press
of the INPUT button will select the
BYPASS input. Another press of
the INPUT button will return the
selection to Input 1.
(2) MUTE: This button will
immediately mute the outputs
of the preamplifier. The volume
display will continue to show the
present
location of the volume
control.
Pressing this button a
second
time will reactivate the
outputs of
the preamplifier.
Remote tRansmitteR opeRation
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
11
(7) BATTERY REPLACEMENT: When the remote begins to become
weak or will not function, it is likely necessary to replace the battery.
Access to the battery is gained by removing the two Phillips head screws
that secure the back cover of the remote transmitter unit. The old battery
can be removed from the snap-on BATTERY TERMINAL and a new
battery reinstalled. A standard alkaline battery is recommended.
NOTE: When removing the old battery, wait at least 30 minutes before installing a new battery
to allow the internal circuitry to discharge completely and reset.
(5) BAL L: This button will shift the output of the preamplifier towards
the left channel. Each press of the button will increase the output of
left channel by 0.5 dB and decrease the level of the right channel by
0.5 dB. A total shift of 6 dB is possible. The balance control is not
continuous; holding the button down will not continue to shift the
balance. The button must be repeatedly pressed to continue to
activate the balance shift towards the left channel.
(6) BAL R: This button will shift the output of the preamplifier towards
the right channel. Each press of the button will increase the output of
right channel by 0.5 dB and decrease the level of the left channel
by
0.5 dB. A total shift of 6 dB is possible. The balance control is not
continuous; holding the button down will not continue to shift the
balance. The button must be repeatedly pressed to continue to
activate the balance shift towards the right channel.
NOTE: To return the bal ance to the center or 0 dB position, press and hold the MUTE
button on the front panel of the preamplier for 3 seconds. This will reset all micropro-
cessor controlled functions and return the balance position to L/R +/-0 dB.
7

PO BOX 7231, COLORADO SPRINGS, COLORADO 80933 USA E-mAIL: [e-mail] www.jEffROwLAND.COm TELEPHONE [phone]
12
1 2 64 5 73
(1) INPUT INDICATORS: Inputs 1 through 5 have a small indicator light above the Input Selector
Buttons. An indicator will illuminate blue when selected to show that the input is currently active.
(2) INPUT SELECTOR BUTTONS: Pressing these buttons selects an input source (CD, tuner,
phono, etc.)
connected to the associated rear panel inputs (see Rear Panel Signal Connections
on page 14). To select a
desired input, press the corresponding Input Selector Button. When an
input is activated, the small, blue Input
Indicator above the Input Selector Button will illuminate.
Before attempting any system interconnection,
please familiarize yourself with the front panel
controls and indicators of the CONCERTO
Stereo Preamplifier. The descriptions refer to
the illustration below.
Front Panel Functions
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
13
If desired, the volume display can be config-
ured to turn off 5 seconds after receiving any
command from the front panel or the Remote
Transmitter. Please contact your dealer
about this function. The volume display
also contains the infrared (IR) receiver for
receiving remote commands.
(7) VOLUME CONTROL:
Rotation of the
volume control knob clockwise will increase
the output level of the CONCERTO. Rotation
of the knob
counter-clockwise will decrease
the output level. The CONCERTO
features
a dual-range volume control system: rotating
the volume knob
slowly will cause the volume
to increase or decrease in small, precise
steps. Rotating the knob abruptly will result in
large, immediate changes to the output level.
NOTE: When the volume control is set to 79.5, the
preamplier is set for unity (0 dB) gain from any input
to any output.
(4) PHASE : Pressing this button will invert the
phase of both channels
of the selected input
and illuminate the green indicator light above
the PHASE button. Pressing this button again
will turn off the light and return the phase to
uninverted polarity.
(5) MUTE MODE:
Pressing the MUTE button
will mute the speaker and line outputs of the
CONCERTO and illuminate the red indicator
light above the MUTE button. Pressing this
button again will turn off the light and restore
the output of the amplifier to the previous
volume setting. To avoid spurious noises and
possible damage to other system components,
the amplifier should be muted when connecting
or disconnecting any rear panel connections.
(6) VOLUME DISPLAY: This display shows the
current volume of the selected input numeri-
cally, from 00.0 to 99.5, in 0.5 dB increments.
(3) BYPASS MODE: The Bypass Mode
allows the CONCERTO to be installed in a
home theater or surround sound system for
optimal playback of stereo music sources
when the multi-channel system is not in use.
Pressing this button will allow a multi-
channel
processor to bypass the amplifier functions
of the CONCERTO, with the volume controlled
only by the external processor.
The indicator
light above the BYPASS button will illuminate
yellow to show that the Bypass function is
active.
NOTE: Do not connect a source component to the
BYPASS INPUTS if it does not have its own volume
control. The volume control of the CONCERTO is
inactive when Bypass Mode is selected.

PO BOX 7231, COLORADO SPRINGS, COLORADO 80933 USA E-mAIL: [e-mail] www.jEffROwLAND.COm TELEPHONE [phone]
14
(1) UNBALANCED INPUTS: If you are using unbalanced RCA interconnects from your source
components (CD player, tuner, etc.), they should be connected to unbalanced INPUTS 1 and 2.
If you have had the optional phono section installed in the CONCERTO, the interconnects from
the turntable should be installed into INPUT 2. For more information about the phono option,
please contact your dealer.
NOTE: An RCA “shorting” plug must be installed into PHONO/INPUT 2 if phono cards are installed and your phono
turntable is not connected. See phono card adjustments section.
The CONCERTO Stereo Preamplifier offers
unprecedented compatibility with associ-
ated audio and A/V components. When
connecting or disconnecting interconnect
cables, the preamplifier should be placed
in Mute Mode (red MUTE indicator LED
on the front panel ON).
ReaR Panel Signal ConneCtionS
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER
4 5 4
42
11 1 1
3 23
1
2
1
24

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
15
(3) BYPASS INPUTS: If the CONCERTO
is installed in a home theater or surround
sound system, the Left Front and Right
Front output connections from the surround
processor should be installed in the BYPASS
input connections. The CONCERTO will only
accept balanced XLR interconnects from
the surround processor. If an unbalanced
connection is required, install an XLR to RCA
adapter, available from your JRDG dealer.
(4) PREAMP OUTPUTS: The CONCERTO
has two sets of balanced line-level outputs
for amplification, powering of an active
subwoofer, or for feeding audio to a amplifier
in a separate room or zone. If your additional
amplifiers accept only RCA unbalanced
cables, it is recommended that the XLR
balanced outputs are converted to RCA
outputs with a balanced single-ended adaptor
box (Model PC-2XR) available from Jensen
Transformers, www.jensen-transformers.com.
(2) BALANCED INPUTS: If you are using
balanced XLR interconnects from your
source components, they should be
connected to balanced INPUTS 4 and 5.
A
slight mechanical click may be heard
when the balanced XLR interconnect cables
are correctly installed and locked into the
rear panel connector. The unlocking tab
must be pressed to disconnect the XLR
interconnect
cable from the preamplifier.
The XLR inputs
may be left open if unused.
Any XLR input can be converted to RCA
input by installing an XLR to RCA adapter,
available from your JRDG dealer.
NOTE: Pin 2 of each XLR connector is signal posi tive
with respect to each RCA input. Also, JRDG recom-
mends balanced cables as the
preferred method of
interconnection.
NOTE: Both sets of line level outputs have equal output
levels. Thus, if Preout B outputs are used to feed a
separate room or zone, they cannot be controlled
independently from the main room.
(5) GROUND LUG THUMBSCREW: This
connection is reserved for units with the
optional phono section installed. When
connecting a turntable, the ground or earth
lead should be connected to the Ground
Lug Thumbscrew to eliminate any ground
noise in the system.

PO BOX 7231, COLORADO SPRINGS, COLORADO 80933 USA E-mAIL: [e-mail] www.jEffROwLAND.COm TELEPHONE [phone]
16
B ADC
Please strictly follow the following steps in
order before operating your CONCERTO
Stereo Preamplifier.
WARNING: If the unit is plugged into a voltage
different from the range listed on the back
panel, serious damage to internal circuitry will result
and will void the warranty.
STEP 1: Verify that the VOLTS AC input (A) identified on the rear panel near the AC input
socket is the same as the AC mains voltage in your area.
STEP 2: Install the AC Power Cable into the AC input connector (B) between the preamplifier
and your AC mains outlet.
STEP 3: Turn on the master AC power switch (C).
ReaR Panel POWeR COnneCtiOns
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
17
POWER CONDITIONING: AC power conditioners and AC mains power cables are a common
accessory in many high performance audio and video systems and can be used to improve the
quality of reproduction in certain instances. We have tried to provide the best possible basic
power cord with the CONCERTO; however, many users may wish to use aftermarket AC power
cords available from many cable manufacturers . Since we have not found an optimal universal
power conditioner or cable we cannot recommend any particular type or brand for use with the
CONCERTO. Please use your dealer’s help and knowledge as a resource to select the proper
accessories for your individual system needs.
NOTE: Due to the exceptionally low power consumption rating of the CONCERTO, it is recommended that the unit simply
be left on when not in use. Also, the CONCERTO includes a user-accessible fuse (D) for added safety and protection. In
the unlikely event that this fuse has blown, it must be replaced with an exact match. (230V, 315A, or 100/120V, .630A)
WARNING: Serious damage to internal circuitry can occur if improperly wired or unapproved AC power cords are
used. Your dealer can be a helpful resource for selecting the proper accessories for your needs.

PO BOX 7231, COLORADO SPRINGS, COLORADO 80933 USA E-mAIL: [e-mail] www.jEffROwLAND.COm TELEPHONE [phone]
18
Overall Gain 20 dB
Gain Range 99.5 dB, 199 Equal Increments
Gain Resolution 0.5 dB, +/- 0.03 dB Over Entire Range
Frequency Response 10 Hz – 280 kHz, -3 dB
Maximum Input Level 15 volts RMS @ 0 dB Gain
Maximum Output Level 13.5 volts RMS
CCIF Intermodulation Distortion, 19/20 kHz < .002%
Output Noise Level 43 Microvolts, Unweighted
20 Hz – 20 kHz Bandwidth, 0 dB Gain
Common Mode Rejection Ratio > 90 dB, 20 Hz – 20 kHz
Input Impedance 40K ohms Balanced or Unbalanced
Channel Separation > 90 dB, 20 Hz – 20 kHz
Inputs
2 pair Balanced (XLR)
1 pair Unbalanced (RCA) Unity Gain (Bypass)
3 pair Unbalanced (RCA)
Outputs 2 pair Balanced (XLR) Line Level
Power Consumption 7 watts
Preamplifier Weight
21 lbs. / 9.8 kg
Overall Preamplifier Dimensions (H) x (W) x (D) 3.2” x 17.3” x 12.9”
80mm x 440mm x 328mm
SPECIFICATIONS
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER

© Jeff Rowland design gRoup 2007. all Rights ReseRved.
19
OWNER’S MANUAL CONCERTO STEREO PREAMPLIFIER
12.9 in. (328 mm)
3.2 in. (80 mm)
11.5 in. (292. mm)
2.6 in. (67 mm)
17.3 in. (440 mm)
DIMENSIONS