Page 1
Table of Contents
Page
Product Concept and Description
.....................................................................................
1
Packaging and Features
.................................................................................................
1, 2
The Rationale for High Power Amplification
.................................................................
3
Compatibility
......................................................................................................................
3
Summary
.............................................................................................................................
3
Unpacking
..........................................................................................................................
4
Installation
..........................................................................................................................
4
Cable and Adaptor Selection
............................................................................................
4
Custom Made Cables
.........................................................................................................
5
Electrical Connections
.......................................................................................................
5
Operation
............................................................................................................................
5
Bridged Operation Diagram
.........................................................................................
6, 7
Cello Limited Warranty
.....................................................................................................
8
Warranty of Repair Work Performed
...............................................................................
8
Product Registration and Transferability
.........................................................................
8
Tampering/Abuse/Misuse
.................................................................................................
9
Service
................................................................................................................................
9
Maintenance
.......................................................................................................................
9
Specifications
...................................................................................................................
10
Page 2
1
INTRODUCTION...
Congratulations on choosing the Duet 350 Amplifier. Your unit has been individually
handmade from the finest parts and materials. The Duet 350 utilizes proprietary Cello
circuitry that represents true state-of-the-art in audio electronics and is designed to
perform to "as-new" specifications for decades of musical enjoyment. We want your
Duet 350 to provide you with complete satisfaction. Please read this manual carefully
and care for your Duet 350 so that it will retain its value, beauty and performance. If
you have any questions, contact your authorized Cello Designer or call the factory. It
is our wish to assist you in every way, now and in the future.
Product Concept and Description
In 1986 Cello introduced the Performance Amplifier, a no-compromise four chassis
set of two mono supplies and two mono amplifiers. The Performance Amplifier has
become a legend in its time because of its extremely natural sound, lightning-fast
response, almost unlimited power, and exceptional reliability. While the Performance
Amplifier was designed as a reference standard without cost restrictions, the more
affordable Duet 350 offers a similar combination of qualities in a single, stereo
chassis.
The principal difference between the Performance and the Duet 350 is that
the Performance, with 40 output devices per channel, has greater output current for
driving ultra-low impedance loads. For most 4 to 8 Ohms speakers, the Duet 350 is
the natural mate. Its twelve output devices per channel, coupled with the most
sophisticated circuitry, give it tremendous capabilities. In normal stereo mode, it has
more than enough power to drive most speakers to their limits with the kind of open,
clear, effortless sound coupled with high speed and powerful dynamics that are the
hallmark of Cello. In bridged mode, accomplished with the flick of a toggle on the
rear panel, the Duet 350 becomes a devastating 1.2 kiloWatt mono block power
station for those who have the speakers to withstand it. In stereo or bridged mode the
Duet 350 is the music lover's dream-come-true amplifier.
Packaging and Features
The Duet 350 chassis is an imposing 11 inches (28cm) high. The height is designed
to accommodate a number of vertically large subassemblies including circuit boards,
heatsinks, and power supply components. In particular, twelve large output devices
per channel require substantial heatsinking. As an alternative to fan cooling, large,
vertically-oriented passive heatsinks are provided for each channel.
