Model 304 Owner`s Manual - Photo.cdr

Model 304 Owner`s Manual - Photo.cdr
Model 304
Multi-Channel Power Amplifier
Owner’s Manual
Table of Contents
Introduction.......................................................................................................................................4
Product Features...............................................................................................................................5
Initial Inspection.................................................................................................................................7
Package Contents.............................................................................................................................7
Unpacking the Amplifier.....................................................................................................................9
Maintenance, Cleaning, and Protection..........................................................................................11
Installation, Use, and Care...............................................................................................................12
Front Panel Functions and Indicators...............................................................................................15
Rear Panel Power Connections........................................................................................................17
Rear Panel Signal Connections........................................................................................................19
Internal Adjustments........................................................................................................................20
Specifications..................................................................................................................................21
Dimensions......................................................................................................................22
Additional and Contact Information................................................................................................23
3
Introduction
Welcome to the Jeff Rowland Design Group “family ” and congratulations on your purchase of what is
unquestionably one of the world's finest audio power amplifiers. With its combination of features such
as numerous function control and interconnect possibilities, precision electronic circuitry, exceptional
efficiency, and accurately machined chassis components throughout, your Model 304 MultiChannel Power Amplifier 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
amplifier. 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 Model 304
Multi-Channel Amplifier serial number begins with the letters “MC.” This number is recorded below
and is also located on the rear panel of the chassis.
Please include this number with any
correspondence regarding your Model 304 Multi-Channel Power Amplifier. It has been my joy to
create an audio component of enduring value that reflects the higher ideals of musical and artistic
expression. It is my hope that these qualities will enrich your experience of ownership.
Enjoy the music!
Jeff Rowland
President,
Jeff Rowland Design Group
Jeff Rowland
Rowland Design
DesignGroup
Group
P.O. Box
Box 7231
7231 Colorado
ColoradoSprings,
Springs,Colorado
Colorado80933
80933
Tel: 719-473-1181
719-473-1181 Fax:
Fax:719-633-4158
719-633-4158E-mail:
E-mail:
jrdg@jeffrowland
jrdg@jeffrowland.com
.com Web:
Web:www
www.jeffrowland.com
.jeffrowland.com
4
Product Features
!
XLR input connectors for balanced system configuration.
!
RCA input connectors for unbalanced system configurations.
!
User selectable switching between balanced and unbalanced connections.
!
Transformer coupled inputs provide universal compatibility with other components and eliminate
ground loop noise and EMI.
!
Four channel capability allows use in multi-channel systems as well as providing four channels of
discreet amplification for multi-amped stereo systems.
!
Ultra-high efficiency output section generates high power output with very little heat.
!
Fully-balanced circuit topology implemented from input to output.
!
Power Factor correction in power supply reduces AC line harmonic noise pollution and increases
AC line power utilization to 99%.
!
Proprietary switch-mode power supply technology ensures consistent performance under all
operating conditions.
!
12V remote ON/OFF remote power switching via 1/8” jack on rear panel.
!
CE approved speaker output terminals require no tools for secure, low resistance connections.
!
Standby power mode reduces warm-up time.
!
Fail-safe operation provided by user-resetable thermal circuit breaker located on rear panel.
!
Quiet, transient-free operation during power ON/OFF and input configuration switching.
!
Selectable overall gain of 26 or 32 dB.
!
Ultra-low resonance, structurally rigid chassis constructed of precision-machined aircraft grade
6061-T6 aluminum.
!
3-point self-leveling chassis support.
5
Package Contents
WARRANTY REGISTRATION
Compliant Isolation
Pads
AC Power Cable
Warranty Card
Care
Care and Maintenance
Instruction Card
OWNER’S MANUAL
Owner’s Manual
Model 304 Multi-Channel Power Amplifier
6
Initial Inspection
Inspect the shipping container for damage.
If the shipping container, packing material, amplifier, or
accessories are damaged or missing, notify your dealer and the shipper (if a claim is to be made)
immediately. Note: Many shippers require notification and inspection within twenty-four hours of
delivery to determine the nature of damages incurred.
Your Model 304 Multi-Channel Power Amplifier has undergone extensive performance evaluations,
listening tests, quality control inspections, and a minimum seventy-two hour burn-in period prior to
shipment and should therefore be in perfect operating condition upon receipt. If the amplifier does
not operate correctly, please notify your dealer immediately.
We strongly suggest that you save all packing materials. If the amplifier is returned to your dealer or Jeff
Rowland Design Group, the original packing materials must be used for shipment to avoid damage.
Neither Jeff Rowland Design Group 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 Jeff Rowland
Design Group issue a Return Authorization (RA) number prior to shipment.
Contents
Ensure that all of the auxiliary components listed below are enclosed within the shipping carton and
accessory box. Refer to the diagrams illustrated on the adjacent page and verify that the proper
components are included.
1
One (1) AC Power Cable
2
One (1) Warranty Card (In some countries, warranties are provided by the respective importer.)
3
One (1) Care and Maintenance Instruction Card
4
One set of three (3) Compliant Isolation Pads
5
One (1) Owner’s Manual
6
One (1) Model 304 Multi-Channel Power Amplifier
7
Unpacking the Amplifier
1
2
4
3
5
8
Unpacking the Amplifier
Amplifier
The Model 304 is a large and heavy amplifier. Due caution should be taken when unpacking and
installing the amplifier to avoid injury or damage to the amplifier. The Model 304 should be unpacked
by at least two people, however it is possible for one person to unpack the amplifier safely. There
should be a portion of carpet or soft, padded cloth to stand the amplifier on when unpacking it from
the shipping box.
To unpack the amplifier:
K
Stand the shipping box vertically and open one end of both the inner and outer box.
L
Pull all box flaps back and turn the carton so that it is standing face-down onto the open end.
M
Carefully lift both boxes up and off of the amplifier and packing material.
N
Remove the packing material cap from the upper end of the amplifier and untie the
protective cloth bag. Pull the cloth bag back to expose the amplifier.
O
Lay the amplifier down on its feet. Remove the remaining packing cap and the cloth bag .
The amplifier is now ready for installation.
9
Amplifier Maintenance, Cleaning, and Protection
10
Amplifier Maintenance, Cleaning, and Protection
Maintenance and Cleaning
All Jeff Rowland Design Group products are designed to provide a lifetime of enjoyment and listening
pleasure. The chassis is sealed to prevent dust from entering and the interior of the chassis should not
need cleaning during the lifetime of the product. All internal circuitr y is self-adjusting such that no
adjustments or maintenance 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 Model 304 Multi-Channel Power Amplifier is uniquely constructed from a number of precision
machined aluminum subassemblies. The front panel of the unit is machined in a unique process that
incorporates a diamond tipped cutting tool. This process was refined over many years to produce an
artistic and attractive finish.
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 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 top cover, sides, and bottom cover can all be cleaned with a soft cotton cloth (such as an
optical lens cleaning cloth or fine furniture polishing rag) dampened with plain water. Water
should be applied directly to the cloth and not the chassis. If a mark has been left on the
chassis, do not use any type of abrasive or chemical cleaner to remove the mark. A ver y mild
plastic or glass cleaner that does not contain ammonia should be tried only as a last resort.
Please contact the factory before tr ying any type of cleanser on the chassis other than water to
clean the unit.
The front panel of the unit should never be cleaned with anything other than a very soft cotton
cloth and plain water or fine oil-based furniture polish. Because of the fine finish of the front
panel, small scratches from the use of any other agent to clean the front panel will become
very visible.
If you have any questions about the care or cleaning of your Model 304 amplifier, please contact your
dealer or the Jeff Rowland Design Group 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.
Protection Systems
The Model 304 Multi-Channel Power Amplifier is equipped with active circuitry and thermal circuit
breakers for protection against excessive AC mains voltage. 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 amplifier will not be
used for extended periods of time, the amplifier 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 travel throughout an interconnected
system.
11
Amplifier Installation, Use, and Care
Locate the amplifier as close as possible to its final installation point. Allow access to the rear panel for
making connections.
The Model 304 Multi-Channel Power Amplifier is extremely efficient and convection cooled,
eliminating the need for fans or forced-air cooling. Multiple chassis can be stacked vertically,
facilitating an upward flow of warm air currents throughout the vertical heatsink areas. This upward
flow must not be blocked or recirculated around the chassis if proper cooling is to be maintained.
Typical installations allow the amplifier to be rigidly coupled to a support structure or floor via optional
spiked coupling supports that are available separately from JRDG. In carpeted installations, these
supports provide excellent anchoring from the amplifier chassis to the rigid floor or sub-floor below. If
there is concern about damage to the structure or floor's finish, a coin can be placed beneath each
spiked coupling support. In installations where the resonant properties of the supporting structure are
poor or unknown, the amplifier chassis can be loosely coupled to the supporting structure via the
supplied compliant isolation interface pads. This will help to attenuate the transfer of vibration or
resonant energy from the support structure to the amplifier chassis.
For rack-mounted or custom applications, a rack-mountable faceplate can be ordered and
manufactured by Jeff Rowland Design Group. Please contact your dealer or distributor with questions
about custom rack-mountable faceplates and delivery times. Note: Please keep in mind that the
Model 304 is a very heavy amplifier and that additional support will be required from beneath the
amplifier. The faceplate alone is not sufficient support for total weight of the amplifier!
The Jeff Rowland Design Group Model 304 Multi-Channel Power Amplifier has been designed with
comprehensive protection circuits that allow the amplifier to operate at the highest level of efficiency
and performance in any normal operating situation. However, there are a few important use and
care principles that must be kept in mind when operating the amplifier:
!
!
!
!
!
!
12
Do not expose the amplifier to rain, moisture, or excessively damp conditions.
Do not disconnect the amplifier from AC mains unless absolutely necessary and without first
placing the amplifier in Standby mode.
The Model 304 Multi-Channel Power Amplifier must not be modified in any way, other than
according to official service bulletins from Jeff Rowland Design Group. Otherwise, the factory
warranty will be immediately voided.
The Model 304 Multi-Channel Power Amplifier can be operated at a nominal 100, 120, 220, or
240 volts AC. The amplifier must be wired for the correct AC input voltage before operation or
serious damage will result.
To clean the Model 304 Multi-Channel Power Amplifier, use a soft cloth moistened with plain
water. Never apply water, dusting sprays, solvents, abrasives, or cleaning fluids directly to the
chassis!
Be sure the amplifier is in STANDBY mode (front panel indicator light OFF) before connecting or
disconnecting any loudspeaker or interconnect cables.
Amplifier Installation, Use,
Use,and
andCare
Care(Cont.)
(Cont.)
!
!
!
When operating the Model 304, 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 output terminals or loudspeaker cables should never be shorted to each other or to
ground. Shorting of the outputs will result in damage to the output section.
The Model 304 is designed to perform optimally with no adjustments or maintenance. In the
event of servicing, do not attempt to open the top cover of the amplifier and refer all service
issues to qualified personnel. The voltages inside the Model 304 can be hazardous.
13
Amplifier Front Panel Functions and Indicators
Front Panel
Power/Standby Button
14
Front Panel
Power/Standby Indicator
Amplifier Front Panel Functions and Indicators
Before attempting any system interconnection, please familiarize yourself with the front panel control
of the Model 304 Multi-Channel Power Amplifier. The descriptions below refer to the illustration on the
adjacent page.
FRONT PANEL STANDBY/POWER BUTTON: Press this button to operate the amplifier. Press again to
place the amplifier in Standby mode.
FRONT PANEL STANDBY/POWER INDICATOR: This small, blue light will illuminate when the amplifier is
operational. When the light is not illuminated, all amplifier inputs are muted and internal circuitry
reverts to power-saving (Standby) mode.
To avoid spurious noises and possible damage to the amplifier's internal circuitry, the amplifier should
be switched to Standby mode when connecting or disconnecting any rear panel connections.
Note: All ON/OFF power switching should be initiated ONLY with this button. The amplifier should not
be disconnected from AC power without first placing the amplifier in Standby mode. Avoid the use of
switched AC power outlets to control or switch AC power to the amplifier.
15
Amplifier Rear Panel Power Connections
CH
4
CH
3
CH
2
CH
UNBALANCED
INPUTS
UNBALANCED
INPUTS
INPUT
1
INPUT SELECT
SELECT
SELECT
NEUTRIK
NEUTRIK
NEUTRIK
NEUTRIK
PUSH
BALANCED
INPUTS
PUSH
PUSH
PUSH
BALANCED
INPUTS
MODEL 304
MULTI-CHANNEL
POWER
AMPLIFIER
MADE IN U.S.A.
SPEAKER
OUTPUT
4
SPEAKER
OUTPUT
3
SPEAKER
OUTPUT
2
SPEAKER
OUTPUT
1
1200 W. MAX
VOLTS AC
SERIAL
NUMBER
MC0000
AC MAINS
PUSH TO RESET
REMOTE
ON / OFF
12V
5
A
M
P
CAUTION
TO PREVENT FIRE OR SHOCK HAZARD, DO NOT
REMOVE COVER. DO NOT EXPOSE TO RAIN OR
MOISTURE. NO USER SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
REFER TO OWNERS MANUAL BEFORE OPERATING.
4
16
1
3
2
Amplifier Rear Panel Power Connections
Important: Please strictly follow the following steps outlined below in order before operating your
Model 304 Multi-Channel Power Amplifier.
K
Verify that the VOLTS AC input identified on the rear panel near the AC input socket is the
same as the AC mains voltage in your area. If the voltage does not match, DO NOT
CONNECT THE AMPLIFIER TO AC POWER and contact your dealer immediately.
L
Verify that the AC MAINS circuit breaker is closed (no white area visible on breaker).
M
Install the AC Power Cable between the amplifier and your AC mains outlet.
N
Connect the 12V Remote ON/OFF Mini-plug Connector (See Below).
Note: Due to the exceptionally low power consumption rating of the Model 304, it is recommended
that the unit not be disconnected from AC mains unless the amplifier is to be moved or reinstalled in
another location. It is recommended that the amplifier be placed in Standby mode rather than
disconnected from the AC mains power when the amplifier is not in use.
The 12V REMOTE ON/OFF 1/8” (3.5 mm) mini-plug connector (4) is provided on the rear panel of the
Model 304 for remotely switching the amplifier between Operational and Standby modes. When
connected to another component with the proper circuitry, the amplifier standby function can be
turned ON and OFF remotely in a custom installation, theater, or automated system setup.
Connection requirements are illustrated below.
Please be aware that the remote feature simply places the amplifier in STANDBY mode and does not
disconnect the unit from power or AC mains.
Please contact your dealer for further information about the use and configuration of this feature.
Constant 3V
3Vto
to15V
15VDC
DCSignal
Signal
(12VDC Typical)
Typical)
Ground
Detail of Mini-plug Connector
17
Amplifier Rear Panel Signal Connections
CH
2
1
3
4
CH
3
CH
2
CH
INPUT
1
UNBALANCED
INPUTS
UNBALANCED
INPUTS
INPUT SELECT
SELECT
SELECT
NEUTRIK
NEUTRIK
NEUTRIK
NEUTRIK
PUSH
BALANCED
INPUTS
PUSH
PUSH
PUSH
BALANCED
INPUTS
MODEL 304
MULTI-CHANNEL
POWER
AMPLIFIER
MADE IN U.S.A.
SPEAKER
OUTPUT
4
SPEAKER
OUTPUT
3
SPEAKER
OUTPUT
2
SPEAKER
OUTPUT
1
1200 W. MAX
VOLTS AC
SERIAL
NUMBER
MC0000
AC MAINS
PUSH TO RESET
REMOTE
ON / OFF
12V
5
A
M
P
CAUTION
TO PREVENT FIRE OR SHOCK HAZARD, DO NOT
REMOVE COVER. DO NOT EXPOSE TO RAIN OR
MOISTURE. NO USER SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
REFER TO OWNERS MANUAL BEFORE OPERATING.
7
18
6
5
4
Amplifier Rear Panel Signal Connections
The Model 304 Multi-Channel Power Amplifier offers unprecedented compatibility with associated
audio components. When connecting or disconnecting speaker or interconnect cables, the
amplifier must be placed in Standby mode (blue POWER INDICATOR LED on the front panel OFF).
If you are using balanced XLR interconnects from your preamplifier or source component, position the
INPUT SELECT switch (1) to BALANCED INPUT. If you are using unbalanced RCA interconnects, position
the INPUT SELECT switch to UNBALANCED INPUT.
Connect the corresponding interconnect cables to either the BALANCED INPUTS (2) or UNBALANCED
INPUTS (3) on each channel. Both RCA and XLR inputs cannot be used for the same channel
simultaneously. For example, an unbalanced output connection from a surround processor and a
balanced output connection from a CD player cannot both be connected to the same channel at
the same time.
A slight mechanical click may be heard when the balanced XLR interconnect cables are correctly
installed and locked. The unlocking tab (located on the input connector and labeled “PUSH”) must be
pressed to disconnect the XLR interconnect cable from the amplifier.
Unscrew the knob that secures the speaker output connectors on SPEAKER OUTPUT 1 (4), SPEAKER
OUTPUT 2 (5), SPEAKER OUTPUT 3 (6), and SPEAKER OUTPUT 4 (7) and pull the securing block out far
enough to allow access to the binding posts. Install the positive (usually red) loudspeaker cable spade
terminal to the positive (+) binding post and the negative spade terminal to the negative (-) binding
post on all four channels. Secure each loudspeaker connection by tightening the knobs securely with
your fingers.
The Model 304 will only accept spade terminations for loudspeaker cables. Banana plugs or bare wire
connections cannot be used and must be reterminated with spade connections.
The Model 304 has a single pair of output binding posts per each channel. All sets of binding posts are
active with no difference in signal quality.
+ Warning: Both positive and negative outputs are electrically active with respect to chassis
and/or system ground potential. Therefore, this amplifier cannot be used in certain loudspeaker
switching configurations, such as those used in retail demonstrations. Failure to avoid these
precautions may short the outputs to ground and can result in serious damage to the amplifier and
will void the warranty.
19
Internal Adjustments
Overall Gain
The overall gain of the Model 304 Multi-Channel Power Amplifier can be adjusted between 26 dB and
32 dB. The setting from the factor y is 26 dB, which is adequate for the majority of applications, though
some systems involving low efficiency loudspeakers may require the higher gain setting. There is no
sonic difference between the two settings.
Because of the potentially dangerous voltages inside of the chassis, it is recommended that you
contact your dealer for information regarding the overall gain setting adjustments.
Note: Do not attempt to disassemble the chassis of the amplifier and adjust the gain without explicit
instructions from your dealer or Jeff Rowland Design Group.
20
Model 304 Multi-Channel Power Amplifier
Output Power:
Continuous RMS watts, all channels driven
@ 8 ohms
@ 4 ohms
300 watts.
500 watts.
Power Bandwidth:
5 Hz - 60 kHz, -3 dB.
Peak Output Current:
>45 Amps.
Dynamic Range:
117 dBA.
THD + Noise, 0.1W-500W/4 ohm:
<.05%, typically .006 @ 1kHz.
CCIF Intermodulation Distortion, 19/20 kHz:
<.002%.
Damping Factor @ 1kHz:
275.
Overall Gain:
(Balanced or Unbalanced)
Selectable Internal Jumper,
26 or 32 dB.
Input Impedance:
40k ohms.
Common Mode Rejection Ratio:
>90dB, 20 Hz - 20 kHz
Absolute Phase:
Non-inverting, Pin 3 Positive.
Inputs:
User Selectable,
4 x Balanced XLR
4 x Unbalanced RCA.
Outputs:
1 Pair Binding Posts per
Channel.
Power Consumption:
Standby Switch OFF
Standby Switch ON (idle)
Maximum
45 watts.
55 watts.
1200 watts.
Amplifier Weight:
95 lbs./43 kg.
Shipping Container Dimensions:
27” (L) x 21” (W) x 16” (H)/
68 cm (L) x 54 cm (W) x 41 cm.
Shipping Weight:
103 lbs./47 kg.
21
Dimensions
A summary
summary of
ofthe
theamplifier
amplifierchassis
chassisdimensions
dimensions
is indicated
is indicated
below.
below.
18.3 in. (46.9 cm)
10.0 in. (25.4 cm)
14.5 in. (36.8 cm)
15.5 in. (39.4 cm)
16.0 in. (40.6 cm)
10.6 in. (26.9 cm)
22
Additional Information
If you have any additional questions regarding the installation or operation of the Model 304 MultiChannel Power Amplifier, please contact your authorized Jeff Rowland Design Group dealer or check
the Jeff Rowland Design Group web site at http://www.jeffrowland.com.
23
Post Office Box 7231 Colorado Springs, Colorado 80933 USA
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