Cello Encore Amplifier Owner's manual

Brand: Cello

Model: Encore Amplifier

Category: Musical Equipment

Type: Owner's manual

ENCORE AMPLIFIER

OWNERS MANUAL

Serial Number

TABLE OF CON

CONTENTS

Introduction

..........................................................................................

Product Concept and Description

........................................................

Unpacking

............................................................................................

Installation

............................................................................................

Selection of Audio Cables

....................................................................

Connection

...........................................................................................

Operation

..............................................................................................

Bridged Operation

................................................................................

Service

...................................................................................................

Warranty

...............................................................................................

Maintenance

.........................................................................................

Physical Specifications

.........................................................................

Electrical Specifications

........................................................................

Connection Identification Diagram - Stereo and Mono

.....................

Connection Identification Diagram - Bridged Mode

.........................

ENCORE TRUE DUAL MONO AMPLIFIER

Introduction

Congratulations on choosing the

Encore Amplifier. Your unit has

been individually handmade from

the finest parts and materials. The

Encore 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 musi-

cal enjoyment.

We want your Encore Amplifier

to provide you with complete satis-

faction. Please read this manual

carefully and care for your Encore

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.

ENCORE TRUE DUAL MONO AMPLIFIER

Product Concept and Description

CONCEPT

Cello developed the Performance

Amplifier (PA) to obtain the most natural

sound and widest dynamic range from

the finest speaker systems. The Encore

True Dual Mono Amplifier (ETDMA)

offers similar sonic qualities for music

listeners who require the ultimate in

medium power amplification.

DESCRIPTION

The ETDMA consists of two separate

mono amplifiers, each in its own chassis,

held together by a common front plate,

top plate, and rear serial number plate.

Each chassis has its own line cord and, if

separated from the other chassis, operates

as a mono amplifier. Unlike some. "dual

mono" amplifiers on the market which are

really stereo amplifiers with separate

power supplies in a single chassis, the

ETDMA offers true mono amplifier

performance in the size of a stereo unit.

The ETDMA incorporates a number of

engineering advances which allow high

performance in a compact and efficient

design, without fan cooling, providing a

practical and appealing product for

inclusion in music systems of the

finest quality.

■

Power Rating. 50 Watts into 8 Ohms.

20-20KHz with no more than 0.3% .THD

■

Gain.

28.50 dB, unbalanced source,

34.50 dB, balanced source.

■

Input Sensitivity.

752 mV

■

Input Impedance.,

330 KOhms, + Audio

5 KOhms, -Audio.

■

Fuse Type.

3AB 2.5A SB, 100V-120V.

3AB 1.5A SB, 200V-240V.

■

Dimensions.

Front Plate is 4.75" high

by 19" wide by .25" deep. Chassis 3."

high by 17.25" wide by 12" deep.

AUDIO CIRCUITRY

The heart of the ETDMA is the actual

driver board from the PA, without the

heatsink tunnels, driver transistors and

output transistors required for the highest

voltage and current (power) levels. The

ETDMA sounds like the PA because it

utilizes the same circuit board, parts, and

associated circuitry for medium power

performance. A solid copper, nickel-plated

heatsink bracket, specially designed for this

product, takes heat out of the transistors

and evacuates it into the entire chassis

including the top and bottom plates.

Balanced inputs are provided using Fischer

3-pin connectors.

Whether driven from

balanced or unbalanced outputs, the

3-wire input system offers sonic advan-

tages not to be missed by critical listeners

(see Balanced Lines, a paper by Mark

Levinson and Tom Colangelo, available

from Cello, Ltd.). The output power of

the ETDMA is rated at 50W @ 8 Ohms.

Speakers can be driven which present

loads as low as 1 Ohm. The ETDMA

circuitry is exceptionally stable and can be

operated 24 hours a day in residential and

professional applications.

POWER SUPPLY

The ETDMA utilizes a dual choke system

similar to the PA supply, but scaled down

for reduced power requirements of the

audio circuitry.

Most power amplifiers use a capacitor

input system which includes a power

transformer, bridge, and filter capacitors.

They deliver DC operating voltages to

the audio circuitry. Larger and larger

transformers are used to charge bigger

and bigger capacitors, but the peak

demands of musical signals exceed the

energy storage of the capacitors. Some

companies use active, regulated power

supplies for improved sonic quality, but it

ENCORE TRUE DUAL MONO AMPLIFIER

Product Concept and Description, cont.

is not practical to use this approach for

higher power amplifiers. A great deal of

money is spent on taking up space and

creating heat, without addressing AC

mains problems which affect sonic

quality.

Cello's dual choke power supply

system utilizes the entire AC waveform,

not just the peaks (like the capacitor input

system) and is very efficient so that no

cost, space, or heat is wasted (as in the

active regulator system). The high

quality, custom-made transformers and

chokes provide energy storage far beyond

the impression of their physical size. The

advantages of the dual choke input

system are quite apparent on a listening

basis, providing controlled, powerful,

deep bass and other sonic refinements.

SONIC

QUALITY

The first reaction of most listeners is,

"Flow can such a sound come from such a

compact package?" In fact, when Cello

engineers first connected the prototype of

the ETDMA for Mark Levinson to audi-

tion, he got up and checked to make sure

that it really was the ETDMA playing and

not his PA set. After auditioning the

ETDMA, one can appreciate and under-

stand the significance of the PA technol-

ogy better, since it is now available in a

power range that corresponds to what the

largest number of listeners need for their

music systems. The speed and clarity of

the ETDMA is astonishing, with no

hardness in the higher frequencies. The

sound presentation has effortless qual-

ities associated with amplifiers having

higher power ratings, yet with the sonic

refinements and transparency associated

with all Cello products.

CONSTRUCT

ION

The ETDMA utilizes bar-and-plate chassis

construction so that individual panels can

be replaced if necessary. Stainless steel

hardware, gold contacts, and many

premium parts ensure as-new sonic

performance for decades of trouble

free operation.

Most audio products use the same

family of circuits and parts, metalwork

and hardware. If you inspect Cello

products on the inside and outside, you

will find very few parts common to other

audio products on the market. Cello

products cost more because they are built

with superior circuit designs, parts, and

manufacturing techniques for those who

want higher performance, reliability,

freedom from obsolescence, and complete,

long term satisfaction.

SUMMARY

The ETDMA is a compact power amplifier

offering state-of-the-art performance and

construction in the medium power class.

Balanced line inputs, dual choke supplies,

mono construction, copper heatsinks, and

advanced engineering are combined to

offer Cello quality in an attractive and

elegant package.

ENCORE TRUE DUAL MONO AMPLIFIER

Instructions

UNPACKING

The packing box for the Encore Amplifier

should arrive in good condition. Please

look for damage to the carton, although

this is most unlikely due to the strength of

the carton construction. Cut and open

packing carefully and save all foam pieces

and boxes for reuse in the event that the

unit must be shipped in the future.

Should the boxes become lost, please

contact the factory for replacement

cartons.

The carton should contain:

■

Encore Amplifier

■

2 A.C. cables

■ torx wrench

INSTALLATION

Be certain that the amplifiers are installed

so that they have proper ventilation.

Placing the units in small, close-fitting

enclosures is not recommended. Room air

temperature should not exceed 122

degrees F./50 degrees C.

SELECTION OF AUDIO CABLES

Any high quality RCA cables may be used.

For balanced line connections, we strongly

suggest using Cello Strings cable made to

factory specifications. Improperly

constructed cables cause problems. It

takes equipment and experience to make

high quality balanced line terminations.

Cello Strings are available in any desired

length, with a variety of connectors, for

different system requirements.

CONNECTION

(See connection identification diagram

on page A1.)

Make sure the power switches located

on the rear panel of the amplifiers

are "OFF."

Verify that the amplifiers are set to the

same A.C. mains voltage as the A.C.

mains in your home or studio. (A.C.

mains voltage is labeled on the rear

panel of the amplifier.)

Connect the preamplifier outputs or

other driving equipment outputs to

the amplifier inputs located on the

rear panel.

Connect speaker cables to speaker

outputs on the rear panel. Be sure to

keep the spade terminal from rotating

while turning the the screw. Tighten

until there is zero play, then apply an

additional 1/8th

turn to make the

connection snug.

CAUTION: Do not over-tighten, as

you will break the terminal strip.

Install the A.C. cords into the I.E.C.

mains connectors located on the

rear panel.

Connect the A.C. cords to the A.C.

outlets in your home or studio.

NOTE: Do not run A.C. cords, audio

signal or speaker cables under rugs or

sharp objects where they may be damaged.

OPERATION

CAUTION: Do not operate this device if

physical damage has occurred to unit, or

if the unit has been exposed to water or

other liquids, until proper repairs and/or

unit integrity tests have been effected by

authorized personnel.

Be sure all electrical connections are

correct and secure. Triple check them.

Turn peripheral units on first. Avoid

switching these units on and off while

amplifier is on.

Set volume control on preamplifier to

minimum.

Turn amplifier switches to "ON"

position.

Begin source material (turntable, tuner,

CD, etc.) and raise preamplifier volume

control to desired listening level. Enjoy!

NOTE: To remove amplifier from

system, turn down volume then turn

amplifiers "OFF" and reverse steps for

connection.

BRIDGED OPERATION

(See connection identification diagram

on page A2.)

One pair of Encore Amplifier units may

be used as a mono amplifier in bridged

mode. This provides four times the

regular power.

CAUTION: Bridged operation should

only be carried out with the recommen-

dation of the speaker manufacturer.

A bridging kit (P/N: 75-3410-00) is

required to operate Encore Amplifiers in

bridged mode. The kit may be purchased

from your Cello System Designer or

ordered directly from the factory.

ENCORE TRUE DUAL MONO AMPLIFIER

Instructions, cont.

The following bridged operation

instructions are for connecting one pair

of amp units (one channel).

With power "OFF" connect AC cord

as instructed in Encore Amplifier

manual.

Connect input to one amplifier only.

We will call this amp unit "Amp 1."

The second amp unit will be called

"Amp 2."

Connect the input jumper cable,

included in the bridging kit, from the

bridging connector of

Amp 1

to the

input of

Amp 2.

Both are labeled on

the rear panel of your Encore unit.

Connect one speaker's positive (+) or

high lead (usually marked in red) to

the output terminal labeled "H"

(

High) of "Amp 1."

Connect the same speaker's negative

(-) or low lead (usually marked in

black) to the output terminal labeled

"H" (High) of "Amp 2."

Connect the output ground jumper

cable, included in the bridging kit,

from the output terminal labeled "L"

(Low) of "Amp 1" to the output

terminal labeled "L" of "Amp 2."

This channel is now ready for

operation.

To connect for stereo, simply repeat

the procedure in steps 1-6 on the second

set of amps.

CAUTION: Make certain preamplifier

volume is turned down before AC

power of bridged amplifiers is

switched "ON."

SERVICE

Do not attempt to modify the Encore

Amplifier. Should you have any ques-

tions or problems with your Encore,

please contact Cello's Customer Service

Department and allow us to assist

you.

If your Encore requires service, this

department will provide you with a

Return Authorization (R.A.) number and

instructions on how to return your unit

to the factory. All returns to the factory

require an assigned R.A. number.

Returns received without original

packing will be shipped out in Cello

cartons at owner's expense. Replace-

ment packing materials are available

by calling the Customer Service

Department.

CELLO LIMITED WARRANTY

Parts: Five years 100% coverage for

all parts.

Labor:

Five years 100% coverage for

all labor.

Shipping: One year 100% coverage for

all shipping and insurance charges pre-

paid to and from the factory from

anywhere in the world via reasonable

carrier. (Note: Special freight or rush

shipments will incur customer charge.)

After one year, units coming into the

factory must arrive with shipping

charges pre-paid. Return shipping

charges will be paid by the factory.

Warranty of Replacement Parts from

the

factory: The remainder of the

warranty period for the unit or one year

(

whichever is longer) shall be the

warranty applied to any replacement

part(s) issued.

Warranty of Repair

Work Performed:

Any specific repairs or modifications

effected by the factory or authorized

service facility shall be guaranteed for

100% parts and labor for the remainder

of the warranty period for the unit or

one year (whichever is longer).

Transferability:

All of the above war-

ranties are transferable to any succession

of subsequent owners. Please contact

your nearest Cello Designer or the

Customer Service Department at the

factory for details of subsequent owner

warranty registration.

Tampering: Any unauthorized modifi-

cations, repairs or tampering with any

Cello product will void its warranty.

Abuse/Misuse: Any indications of

obvious owner abuse, negligence or

mproper usage, as determined by the

factory, shall void the warranty.

MAINTENANCE

The finish of the Encore Amplifier is of

brushed and anodized aluminum.

Ammonia-based glass cleaner or alcohol

and a soft cloth work well to restore

the shine and remove finger prints. Be

sure that the unit is off and unplugged

before cleaning. Avoid getting excess

cleaning fluid inside the amplifier. Take

care when cleaning rear panel. Do not

rub so hard as to remove the silkscreen

lettering.

ENCORE TRUE DUAL MONO AMPLIFIER

Physical Specifications

ENCORE AMPLIFIER

ENGLISH

METRIC

Height (chassis)

MONO

3.0 in.

STEREO

3.0 in.

MONO

7.6 cm

STEREO

7.6 cm

Height (max.)

4.4 in. 4.9 in.

11.1 cm

12.4 cm

Width (chassis)

8.5 in.

17.0 in.

21.6 cm 43.2 cm

Width (max.)

9.5 in.

19.0 in.

24.2 cm

48.3 cm

Depth (foothold)

10.5 in. 10.5 in.

26.7 cm

Depth (chassis)

12.0 in.

30.5 cm

Depth (max.*)

13.3 in. 13.3 in.

33.7 cm

Box dimensions:

22.0" x 19.0" x 10.5"

55.9 cm x 48.3 cm x 26.7 cm

Weight: Net

28 lbs.

12.7 kg

Boxed

43 lbs.

19.5 kg

All weights are approximate and do not include exterior cabling.

Measurement from the rear of terminal strip covers to front plate.

Does not account for space cabling.

ENCORE

TRUE

DUAL

MONO AMPLIFIER

Electrical Specifications

ENCORE AMPLIFIER

Power Output

Single Amp

Rated

MP (Ohms)

Watts (RMS)

100

Bridged Set

MP (Ohms)

Watts (RMS)

200

MD SMPTE

60Hz & 7kHz

20V ouput

.................................................................

THD

20Hz - 20kHz

8 Ohms 20V output

...............................................

<0.3%

4 Ohms 20V output<0.3%

Frequency Response

20kHz

..................................................................

-0 .3d B

100kHz

.................................................................

-6.0dB

Channel Separation

L-R

.....................................................................

Infinite

Signal to noise

20V output

1kHz

.................................................................

<-100dB

Input Impedance

Non-inverting

...............................................

330kOhms

Inverting

...........................................................

5kOhms

Input Sensitivity

20V output, 8 Ohms

50W (RMS)

..........................................................

1.485V

Gain

......................................................

28.5dB unbalanced

34.5dB balanced

NOTE: All measurements are for one mono amp unless otherwise indicated.

(All specifications subject to change without notice.)

Cello, Ltd.

315 Peck Street, Bldg. 23

New Haven, CT 06513

203 865-1237 FAX 203 624-3679

Cello Encore Amplifier Owner's manual

Brand: Cello

Model: Encore Amplifier

Category: Musical Equipment

Type: Owner's manual

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Cello Encore Amplifier Owner's manual

Cello Encore Amplifier Owner's manual

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