Jeff rowland CONCENTRA User Manual

JEFF ROWLAND

DESIGN GROUP

Concentra

Stereo Integrated Amplifier

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 amplifiers. þ With its combination of industrial grade active and passive devices,

precision electronic circuitry and accurately machined chassis components throughout, your Concentra Integrated

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

remainder of this Owner’s Manual. 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. þ Your Amplifier’s serial number is

located on the rear panel and also recorded below. Please include this number with any correspondence regarding your

Concentra Integrated Amplifier. 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. 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 Three balanced XLR inputs per channel plus three unbalanced (RCA)

inputs per channel.

þ Preamp Out in both balanced XLR output and unbalanced (RCA)

outputs per channel.

þ Tape input and output jacks allow tape recording from any source and

monitoring of tape recorder output.

þ Rear panel handles assist moving and transport of unit.

þ Chassis and all chassis components, precision machined from 6061

aluminum plate, reduce distortion resulting from mechanical resonance
and thermal instabilities.

þ All operational functions under microprocessor control. Within five

seconds of any function selected, the microprocessor reverts to a non­clocking “sleep” mode which eliminates any possibility of digital noise
contamination.

þ Non-multiplexed, zero electrical noise generating numerical display

indicates volume level over entire range of 99.5 decibels.

þ ‘Display off after five seconds’ option available for non-intrusive, low

light listening environments.

þ Dual range volume control allows large volume level changes when

knob is rotated abruptly, yet permits precise small volume level changes
when knob is rotated slowly.

þ Optional plug-in phono cards (installed internally) convert Line Input 1

to high performance phono inputs. Four gain and input loading options
standard for moving magnet and moving coil cartridge types.

þ Full electronic and thermal protection modes guard against output

overloads and short circuits.

þ High current preamp outputs (balanced XLR and unbalanced RCA)

allow simultaneous driving of external power amplifiers for subwoofers,
vertical bi-amping, etc.

þ All inputs are transformer-coupled to provide maximum immunity from

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

þ Speaker outputs are fully balanced to provide maximum sonic

performance and immunity from RF contamination due to high output
common mode noise rejection.

þ Optical encoder type volume control maintains quiet, trouble-free

performance and accuracy over entire lifetime of product.

þ Six-function hand-held IR remote control.

Introduction / Product Features

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Contents

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