Jeff Rowland Coherence 2 Pre, Coherence Pre Owners manual

JEFF ROWLAND

DESIGN GROUP

Coherence

Stereo Preamplifier

Owner’s Manual

Introduction

W

elcome to the Jeff Rowland Design Group “family” and congratulations on your purchase of what is unquestionably

one of the world’s finest audio preamplifiers. þ With its combination of industrial grade active and passive devices,

precision electronic circuitry and accurately machined chassis components throughout, your Coherence Preamplifier will

offer you many years of musically satisfying enjoyment. þ Please take a few moments to read the remainder of this

Owner’s Manual. þ A thorough understanding of the operational features will allow you to gain the maximum

performance and ease of use for which this Preamplifier was designed. þ Please note that your Preamplifier must be

used with its companion Power Supply. þ The serial number of each component is located on the rear panel of each,

and also recorded below. þ The Preamplifier serial number begins with the letter C and the Power Supply serial

number begins with the letter D. þ Please include these numbers with any correspondence regarding your Coherence

Preamplifier. þ It has been my joy to create an audio component of enduring value which will reflect a higher ideal of

musical and artistic expression. þ It is my hope that these qualities will enrich your experience of ownership.

Enjoy the music!

Jeff Rowland

President

þ Jeff Rowland Design Group, Inc.

2911 North Prospect Street

Colorado Springs, CO 80907

Phone: [phone]

Fax: [phone]

Product Features

þ Seven balanced XLR inputs per channel.

þ Two balanced XLR main outputs per channel.

þ Two balanced XLR record outputs per channel.

þ One balanced XLR “bypass” input per channel for use in home theater

installations.

þ All inputs and outputs can be used with single-ended RCA terminated

interconnects by using XLR/RCA adapters (one male stereo pair and
one female stereo pair supplied).

þ Independent Listen and Record functions on each input permit

simultaneous listening and recording from any two selected inputs.

þ Each input can be individually adjusted for R/L balance, mono/stereo,

absolute phase, input impedance, and gain, exclusively independent
of every other input. Individually adjusted input settings are
automatically memorized and recalled when returning to that input.

þ Built-in “pink noise” generator facilitates break-in of preamplifier

components and interconnected associated components.

þ Six-function hand-held IR remote control with separate IR sensor/

display unit for remote IR reception and volume level indication.

þ Chassis and all chassis components precision machined from 6061

aluminum plate provide maximum mechanical resonance control.

þ All operational functions are under microprocessor control. Within five

milliseconds of any function selected, the microprocessor reverts to a
non-clocking “sleep” mode which eliminates any possibility of digital
noise contamination.

þ Transformer-coupled inputs and main outputs provide maximum

immunity from RF contamination and system ground loops and enhance
compatibility with a wide variety of interconnected components.

Power Supply Features

þ Separate power supply provides a stable, low noise DC power source

utilizing reliable, long-life sealed lead-calcium batteries.

þ Microprocessor controlled charge-management system ensures optimum

battery operation under all conditions. The microprocessor is normally
in non-clocking “sleep” mode, except when servicing a short-term
operational command.

þ Two separate power supply outputs for powering additional

companion units such as an optional phono equalizer.

þ Front panel AC/DC mode switch disconnects AC power when DC

mode (pure battery) operation is selected.

þ Chassis and all chassis components precision machined from 6061

aluminum plate provide maximum mechanical resonance control.

Introduction / Product Features

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Contents

1

Initial Inspection

I

nspect 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). Note: Many shippers
require notification and an inspection within twenty-four (24) hours of
delivery to ascertain the nature of damages incurred.

Your Coherence Preamplifier has undergone extensive performance
evaluations, listening tests, quality control inspections and a minimum
seventy-two (72) hour burn-in period prior to shipment and should be in a
perfect operational condition upon receipt. If the Preamplifier does not
operate correctly, please notify your dealer immediately.

We strongly suggest that you save all packing materials. If the Preamplifier
is returned to your dealer or Jeff Rowland Design Group, the original
packing materials must be used for shipment. 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 a Return Authorization number be issued by Jeff Rowland
Design Group prior to shipment.

Contents

E

nsure that all of the auxiliary components listed below are enclosed
within the accessory box. Refer to the diagrams illustrated above and
verify the components included.

1 Remote sensor/display unit

2 Handheld remote transmitter

3 Remote sensor/display unit interconnect cable adapter

(DB-25 male to RJ-11)

4 Remote sensor/display unit interconnect cable

5 Eight (8) compliant isolation interface supports

6 Four (4) XLR/RCA adapters (one pair male input adapters and one

pair female output adapters)

7 AC power cable

8 DC power cable

9 One (1) warranty card (in some countries warranties are provided by

the respective importer)

Initial Inspection / Contents