Q. The remote control on the Synergy has quit working. I've replaced the battery and it's still not working.

A. To restore the remote's operation, remove the battery and wait a few hours until reinstalling the battery to the remote. This should fix the problem.

Q. What are the Different Generations of the Synergy Preamplifier? What Upgrades are Available?

A. There have been three different generations of the Synergy Stereo Preamplifier, The original Synergy preamplifier (1/1996 through 3/1997), the Synergy II Stereo Preamplifier (3/1997 through 12/2000), and the Synergy IIi (1/2001 through present). All Synergy and Synergy II units have a RED volume display. Synergy IIi units may have a GREEN or BLUE volume display.

The Series II Synergy added a set of output transformers to the original Synergy to lower distortion, perform impedance matching between preamp and amp, and decrease noise significantly, and also included a second set of Main Outputs and Record Outputs to allow for bi-amplification and multiple tape or recording systems. The additional outputs are connected in parallel to the original outputs and cannot be controlled separately or independently.

The Series IIi Synergy replaces the original amplifier board within the Synergy and Synergy II with a new, surface mount designed amplifier board and green or blue displays and indicators. This new amplifier board substantially lowers noise and distortion within the preamplifier and increases detail, transient response, and dynamic capabilities dramatically.

The original Synergy can be upgraded to Series II status by installing the output transformers and performing a few modifications to portions of the circuitry. The dual outputs are available as an additional option (the unit must be returned to the factory for the dual output option). Any Series II unit can then be upgraded to IIi status with the installation of the new amplifier board and a new display. A unit must be upgraded to Series II before it can be upgraded to Series IIi. Please contact your local dealer or distributor for upgrade pricing.

Q. What is the difference between the Synergy Series I and Series II?

A. The Synergy Series II preamplifier began production February 1998. The Series II includes dual outputs for increased versatility, as well as output transformers to bring it sonically closer to the Coherence preamplifier.

Q. Can I use my Synergy preamplifier in a home theater set-up?

A. Yes, simply route your processor front right and left channels into the Synergy bypass inputs. When the bypass switch is depressed, the bypass inputs are routed to the Synergy main outputs at unity gain. All controls on the preamp are disabled. Your processor center and rear outputs go to your center and rear amplifiers directly for surround operation. For 2 channel stereo use, simply select any regular input.

Q. Does the red record lamp always stay on when I have my Synergy preamp in the listen mode?

A. Yes.

Q. How do I know if my Synergy is a Series I, Series II, or Series IIi with the new Amplifier Board?

A. The original Synergy had a red volume display and simply had the words "SYNERGY PREAMPLIFIER" printed on the back panel. The Series II version of the Synergy had a red display and the words "SYNERGY PREAMPLIFIER SERIES II"
printed on the rear panel. The majority of Synergy IIi preamplifiers have the words “SYNERGY PREAMPLIFIER SERIES IIi” laser engraved on the rear panel. 

The Synergy IIi units with the new amplifier board can be identified by the green or blue volume display.

Q. Is there an update for my Model 8 amplifier? What is the difference between Model 8 and Model 8T?

A. Yes, all Model 8 amplifiers are eligible for update. Model 8 amplifiers with "Model 8T" nomenclature on the rear panel, serial numbers B80001 through B80055, are also eligible (See Stage 3 update below).

All update stages require that the amplifier be returned, in the original factory shipping case, to the Jeff Rowland Design Group factory. A return authorization number must be issued by JRDG which will indicate the date on which the unit may be shipped to the factory. Jeff Rowland Design Group will arrange the freight forwarding carrier and instructions for the most efficient, cost effective transit both to and from the JRDG factory. All shipping and related charges will be the responsibility of the end user and/or dealer/distributor.

Stage 1:

Model 8 amplifiers between serial numbers A80001 and A80102 may need additional work involving the replacement of power supply components before the unit can be eligible for the Stage 2 update. These units were originally designed with a single "choke-input" power supply which simultaneously powered both right and left channels. The Stage 1 update provides a "dual mono" power supply which consists of totally isolated right and left channel power supplies which allow completion of the Stage 2 update. Since many of the original Model 8 amplifiers (serial numbers A80001-A80102) have already been modified to this stage, it may be necessary to inspect the internal layout of the amplifier in question. Original, unmodified units can be identified by two large black capacitors placed longitudinally from the front to the rear of the amplifier. All modified units can be identified by four large black capacitors placed transversely and clamped between two gold-colored brackets which span the entire length of the amplifier.

Stage 2:

Update is available to all amplifiers from serial number A80001 through B80055. This update can be performed independently from any other update, i.e. A80234 does not require the rear panel with battery power supply connections to be eligible for the Stage 2 update; however, unless the amplifier has connections for use with the battery power supply, the unit will not be able to be used with the BPS-8 battery power supply at a future date.

This update involves minor modifications to each right and left channel main circuit boards and the replacement of each right and left channel plug-in modules.

This update provides the greatest sonic performance improvement possible without utilizing the BPS-8 option.

This update involves minor modifications to each right and left channel main circuit boards and the replacement of each right and left channel plug-in modules.

This update provides the greatest sonic performance improvement possible without utilizing the BPS-8 option.

Q. What was the Latest & Greatest Model 8 available?

A. The Model 8TiHC. This is a high current version of the Model 8Ti; it has twice the number of output devices, therefore doubling available output current on demand.

Q. How do I get my display to turn off after 5 seconds?

A. Click Here.

Q. Will the optional phono stage of the Concentra accept both MC & MM cartridges?

A. Yes.

Q. What are the Differences Between the Concentra and Concentra II? How do I Tell Them Apart? Can an Original Concentra be Upgraded to Series II?

A. The original Concentra (9/1996 through 1/2001) was a 100 watt per channel integrated amplifier. The Concentra II (1/2001 through 10/2003) is a 150 watt per channel integrated amplifier, so the series II version has 50% more output power available. The Series II version of the Concentra also has a completely different power supply layout and design. The new layout is a much quieter source of power, and also has a separate front-end supply. The new layout is circuit board based and features increased common mode rejection as well as offering better isolation between different portions of the amplifier, lowering radiated fields and noise. This new power supply is the primary reason that the sound quality of the Concentra II is much improved. The two versions can be identified easily: the original Concentra has a RED volume display and indicators. The Concentra II has a BLUE volume display and indicators. There is an option to upgrade very early Concentra units with a “standby” mode that allows the unit to run cool and lower power consumption when not in use; however, the original Concentra cannot be upgraded to Series II status. Please contact your local dealer or distributor for upgrade pricing.

Q. Can the phono option be installed later (after I purchase the unit new), or must they be installed at the factory before shipping?

A. The phono option can be installed at the factory or by your local dealer if you choose to add it later. The unit does not need to come back to the factory to have the phono option installed. The phono option is also available for older (original Series I) Concentra units from all Jeff Rowland Design Group dealers and distributors.

Q. If I disconnect my Coherence Preamplifier from AC power, what is the proper procedure?

A. If you disconnect the Coherence Preamplifier from AC power, you must hold the "mode" button on the power supply for 10 seconds, or until a "click" is heard. If you do not perform this disconnect procedure, one of the two internal batteries will continue to discharge, causing a potential battery failure.

Q. What is the difference between Coherence Series I and Series II?

A. The Coherence Series II was released April 1997. The Coherence Series II upgrade involves the redesign of the attenuator amp circuitry. The actual circuit topology is similar; however, all of the circuit components were improved, taking advantage of recently available modern surface mount technology. The output amplifier is a newly developed, dual high-current transimpedance amplifier which handles both phases of the output circuit on one isothermic, copper lead frame power device. This output amplifier and all associated surface mount circuitry allow significant reductions in circuit loop area and path length yielding wider bandwidth, faster setting time, reduced dielectric absorption and greater thermal tracking stability. The overall sonic result is greater clarity during complex music passages and increased resolution of intertransient silence.

BPS Battery Life Expectations

Rechargeable batteries can give many years of faithful service or they can fail in an annoyingly short time. Rechargeable batteries can indeed last a long time if applied properly, however poor charge management, more than anything else, is responsible for the difference between laboratory life and life in the hands of the consumer. Many otherwise intelligent engineers do not appreciate the importance of accommodating the needs of a battery. The few who do are often forced to submit to the pressure of the marketplace for smaller, lighter, and cheaper products without regard for service life.

In the face of numerous challenges, why should you believe that Jeff Rowland Design Group’s Battery Power Supplies would provide a long and trouble-free life? As with all Jeff Rowland Design Group products, the same attention to detail that distinguishes our amps and preamps has also gone into the charge management of the BPS.

After taking care of all the elements of good charge management, battery life comes down to charge/discharge cycles and battery temperature. The sealed lead calcium batteries used in JRDG BPS supplies are normally good for better than 200 deep cycles (discharged fully and recharged). Even this large number is probably low for an SLC battery, since many more, shallower cycles represent typical amplifier use. It would seem that half the depth of discharge would yield twice as many cycles; actually it is even better than that: cycle life improves exponentially as the depth of the cycle is reduced, so most BPS supply owners will not “wear out” their batteries.

Heat is a battery’s worst enemy. Sealed lead calcium batteries are well sealed, as it is not practical to employ a true hermetic (impenetrable) seal. This means that over time water molecules slowly migrate through the battery’s case. After many years, failure occurs because of moisture loss. Failure is slightly quicker in ultra-low humidity environments, but it is temperature that exacts the greater toll. Every degree above the listening room’s ambient temperature lessens the battery’s life and quickens the eventual failure. Therefore, mounting a hot load such as the amplifier in the same chassis is highly undesirable. Normally this would also be the case for a heat source such as the charger, but the Jeff Rowland Design Group BPS uses the same type of machined chassis as the amplifier. Given the relatively small amount of heat generated by the charger and batteries, the temperature rise is relatively small. Keeping the BPS away from heating ducts, direct sunlight, fireplaces, and other heat sources will ensure a very long battery life. With proper care and treatment, it is not unreasonable to expect a battery life of approximately five to seven years.

Cables, Power Line Conditioner, or Other Equipment Recommendations

We are asked almost every day about what cables and AC line conditioners we recommend. To put it very simply: we don’t recommend anything. The reasons for this are simple: there are too many things that can affect the sound of your system that we do not know about or understand, we have a very limited experience with other products, we have never found the “best” possible component or product because every person has different favorites or preferences, and we do not “match” our units with those of other manufacturers.