Model 302 Stereo 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 302 Stereo 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 302 Stereo Amplifier serial number begins with the letter "T." 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 302 Stereo 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 Design Group Rowland Design Group P Box 7231 Colorado Springs, Colorado 80933 .O. Box 7231 Colorado Springs, Colorado 80933 Tel: 719-473-1881 Fax: 719-633-4158 E-mail: jrdg@jeffrowland .com Web: www .jeffrowland.com 719-473-1881 Fax: 719-633-4158 E-mail: jrdg@jeffrowland.com Web: www.jeffrowland.com 4 Product Features ! ! ! ! ! XLR input connectors for balanced system configuration. RCA input connectors for unbalanced system configurations. Dual Speaker Output Terminals on each channel for bi-wiring applications. User selectable switching between balanced and unbalanced connections. Transformer coupled inputs provide universal compatibility with other components and eliminate ground loop noise and EMI. ! ! ! 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 AC Power Cable Compliant Isolation Pads Warranty Card Care Care and Maintenance Instruction Card Owner's Manual Model 302 Stereo Power Amplifier 6 Initial Inspection 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 302 Stereo 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. Inspect the shipping container for damage. 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 2 3 4 5 6 One (1) AC Power Cable One (1) Warranty Card (In some countries, warranties are provided by the respective importer.) One (1) Care and Maintenance Instruction Card One set of three (3) Compliant Isolation Pads One (1) Owner's Manual One (1) Model 302 Stereo Power Amplifier 7 Unpacking the Amplifier 1 2 3 4 5 8 Unpacking the Amplifier Amplifier The Model 302 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 302 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 L M N O Stand the shipping box vertically and open one end of both the inner and outer box. Pull all box flaps back and turn the carton so that it is standing face-down onto the open end. Carefully lift both boxes up and off of the amplifier and packing material. 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. 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 302 Stereo 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 302 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 302 Stereo 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 302 Stereo 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 a ...