Cello PERFORMANCE AMPLIFIER II Owner's Manual

PERFORMANCE AMPLIFIER II

OWNERS MANUAL

Serial Number

TABLE OF CONTENTS

Introduction

Product Concept and Description

Unpacking

Installation

Cable and Adapter Selection

Electrical Connections

Connection Identification Diagram - Supply Chassis

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Connection Identification Diagram - Amplifier Chassis

Choosing Associated Equipment

Operation

Bridged Operation

Maintenance Information

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Block Wiring Diagram for Bridged Operation

Additional Instruction

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Additional Accessories and Parts

Cello Limited Warranty

Service

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1

2

3

3

3

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4

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5

6

6

6

7

8

9

9

9

9

Electrical Specifications

Physical Specifications

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10

11

Introduction

PERFORMANCE AMPLIFIER

Congratulations on choosing the
Performance Amplifier. Your unit

has been individually hand-made
from the finest parts and materials.

The Performance Amplifier utilizes
proprietary Cello circuitry that

represents the true state-of-the-art in

audio electronics and is designed to
perform to specifications for decades

of musical enjoyment.

We want your Performance

Amplifier to provide you with
complete satisfaction. Please read

this manual carefully and if you

have any questions, contact your

authorized Cello supplier or call the

factory. It is our wish to assist you
in every way, now and in the future.

1

PERFORMANCE AMPLIFIER

Product Concept and Description

CONCEPT

The Performance Amplifier is a
no-compromise design for the

ultimate in residential music and
professional monitor systems. A

combination of musical clarity

, high

output voltage and current
capability enables the Performance
Amplifier to maximize the perfor­mance of all high quality speaker

systems. Comprehensively de­signed to be ultra-reliable and stable,

the Performance Amplifier will
satisfy the most demanding user
and provide decades of trouble-

free operation.

DESCRIPTION

The Performance Amplifier is a

stereo system of four chassis: one

mono power supply and mono

amplifier per channel. The power
supply is a dual choke input design.

Unlike capacitor input supplies
which

utilize

only the peaks of the
AC waveform, the choke input
system uses the whole AC waveform

and is much more efficient. Each
audio amplifier chassis employs 8

driver transistors and 40 250W
output devices per channel on two
electrically conductive heat sink tun-

nels cooled by two very quiet fans.

2

Instructions

PERFORMANCE AMPLIFIER

UNPACKING

Inspect the containers for signs of damage
in transit. Report any evidence of abuse
immediately. Open containers carefully

and remove contents from the packing.
Take care not to scratch the surfaces of the
units. Save all boxes and foam pieces for

reuse in the event that the unit must be
moved in the future. If the boxes should

become lost, replacement boxes are
available from the factory.

Contents:

■

2 amplifier chassis

■

2 power supply chassis

■

2 AC power cables

■1DC power cable

■

I set of fuses (5)

■

1 tool kit containing torx key and

'/s

-inch hex key

INSTALLATION

The four chassis can be stacked vertically,

arranged as a pair of supply/amps per
speaker, or arranged as four chassis in a
horizontal row.

When horizontal space is limited, the
units can be set on their front panels. In
this case, place a piece of thick (.2 inches)
cloth, felt or thin foam under each front
panel to prevent scratching its metal
finish.

When arranged in a set of two units
by two units or four horizontally, make
sure that fan exhaust from one amp does
not blow directly into the intake of the

other, or the second set may overheat and

shut off.

When stacked, you may wish to place

the supplies on top because the circuit
breaker/power switches are located on

these units. This is not important if a
remote A.C. switch is used.

Be certain that the amps 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.

CABLE & ADAPTER SELECTION

The Performance Amplifier has three-pin
Fischer connectors for highest quality

balanced line input capability. It is
recommended that input connections be
made using Cello Strings cable. Cello

Strings are stocked in lengths of 1, 2, 5, 8,

and 10 meters. Terminations are available

to suit the particular components of the

system. Custom lengths are available on
special order.

If it is necessary to convert Fischer

inputs to RCA, use the E3 adapters. The

best way to convert to single ended

operation is to use Cello Strings cable
(which has three conductors and a shield)
with Fischer male on one end and RCA
connector on the other. This preserves the
three-wire system from the amplifier to
the source unit and provides better

grounding and common-mode rejection.

To interface with XLR systems, it is
recommended that Cello Strings cable be
used with Fischer male on one end and
XLR female on the other end.

CUSTOM MADE CABLES
(NON-CELLO)

Three-conductor shielded cables should
be used to keep audio(+), audio(-), audio

ground and chassis earth separate.

If single-ended adapters are made, pins
one and three should be jumped and used
as ground, and pin two should be used as
the audio(+).

Connecting audio ground and chassis
ground may or may not cause or solve
grounding problems depending on the
system as a whole.

ELECTRICAL CONNECTIONS

Make sure the circuit breakers on the

1)

supplies are"off".

2)

Install the DC cables according to

the color codes using the DC cables

supplied.

3)

Install each terminal screw and tighten

until there is zero play, then apply an

additional 1/8th turn so that it is snug.

Be sure to keep the spade terminal
from rotating while turning the screw.

Do not over-tighten or you will break
the terminal strip.

4)

Install the terminal block covers.

Again, don't over- tighten.

5)

Verify that AC mains voltage is set

correctly.

6)

Connect the preamplifier or other

driving equipment.

7)

Connect speaker output cables.

8)

Be sure that the electrical service in the
building/house is up to the task,

especially if using two sets of bridged
amplifiers. The recommended ideal

situation is a dedicated line to each amp.

9)

Install AC cables into IEC mains
connector on rear of power supplies.

Connect AC cables to AC mains.

10)
NOTE: The power supply circuit

breaker will trip if the power supply is

not connected to the amplifier.

The Performance Amplifier can be used

as part of a complete Cello System, or in
conjunction with other speakers,
electronics, and cables.

3

PERFORMANCE AMPLIFIER

Instructions (cont.)

The performance Amplifier can be used
as part of a complete Cello System, or
in conjunction with other speakers,
electronics, and cables.

CHOOSING ASSOCIATED EQUIPMENT
The following should be kept in mind:

1)

Speakers should be of a design and
type capable of handling the extremely

high power levels produced by the

amplifier. This is especially important

if you plan to use the bridged amplifier
configuration.

2)

Use only with preamplifiers having

protection against turn-on/turn off
thumps, surges or noises. All Cello
equipment uses muting circuits to
guard against such problems.

3)

Make certain that units such as the CD,

tuner, tape and phono have no major
turn-on turn-off noises. If they do,
turn them on or off only while the
system is not operating.

4)

Any failure of Cello equipment due to
the improper selection and operation

of related non-Cello components shall

void the warranty.

OPERATION

The Performance Amplifier is capable

of producing extremely high voltage
and current levels. Be sure to observe
standard precautions when operating.
The following steps are recommended.

1)

Be sure all electrical connections are
correct. Triple check them.

2) Be certain that the terminal block
covers are installed. Do not run the

Performance Amplifier without these
covers in place.

3)

Do not run power supply cables, AC
mains or audio cables under rugs or

sharp objects.

4)

Turn peripheral source electronics on

first.

Avoid switching these on or off

while amplifiers are in use.

5)

Set volume controls on preamplifier

to minimum.

6)

Turn amp supply switches on.

7)

Bring the volume control up slowly

to the desired level. Use the amplifier
for musical enjoyment. Do not
overdrive to create distortion. The

Performance Amplifier is capable of
damaging loudspeakers if the volume
is up too high.

When you are through switch the
amps off first, before turning off the
peripheral equipment. Leaving the amps
on will not harm them, but be advised
that each unit draws approximately 400
watts at idle.

If physical damage has occurred to the
unit or it is exposed to water or other
liquids, do not use this device until proper
repairs and/or unit integrity tests have
been effected by authorized personnel.

BRIDGED OPERATION
One pair of Performance Amplifiers may

be used as a mono amplifier in bridged
mode. In this case, four times the power
is available.

should only be carried out with the recommen­dation of the speaker manufacturer.

A bridging kit (part number

75-BRDG-00) is required to operate
Performance Amplifiers in the bridged

mode. The kit may be purchased from

CAUTION:

Bridged operation

6

Instructions (cont.)

PERFORMANCE AMPLIFIER

your Cello Designer. The bridging kit
comes with the proper quantity of parts to
convert two sets of Performance Amplifi­ers (four supplies, four amps)to stereo

operation by combining one set of amps
for the left channel and one set of amps
for the right channel.

The following instructions are for
connecting only one set of amps (one
channel). To connect for stereo, simply
repeat the procedure on the second set of
amps. See the block wiring diagram for
bridged operation to identify these
connections.

1)

Connect all AC and DC cables as
instructed previously.

2)

Make all input connections to one
amplifier only.

3)

Connect the input jumper cable from
the bridging output connector of the
first amplifier into the input connector

of the second amplifier.

4)

Connect the speaker high lead to one
of the output terminals labeled "H"

(high) on the first amplifier. Connect
the speaker low lead to one of the
output terminals labeled "H" (high) on
the second amplifier.

5)

Connect the output ground jumper
cable from one of the output terminals
labeled "L" (low) on the first amplifier
to one of the output terminals labeled

"L" (low) on the second amplifier.

6)

Connect the DC bridging cable, using
the color code, from the supply
terminals on the first amp to the
supply terminals on the second amp.

After repeating the above procedure
on the second set of amps the amplifiers
are ready for use in stereo.

Make certain the preamp volume is turned
down to minimum. Turn AC power "on"

for operation.

MAINTENANCE INFORMATION

The Performance Amplifier is essentially a

maintenance-free device designed to last
for many decades of enjoyment. No
routine maintenance or adjustments are
required, however it is recommended that
you undertake two actions.

1.

Periodic cleaning of the foam fan-air
filters.

When these filters become clogged

with dirt and dust, the ability of the

CAUTION:

amplifier to dissipate heat is reduced. To
clean them, gently pull the plastic grille
covers off. Rinse foam filters in cold
water, allow to air dry, then re- install.

2.

Care of finish.
The finish of the Performance Ampli-

fier is of brushed and anodized alumi­num. Ammonia based glass cleaner or

alcohol works well to restore the shine
and remove fingerprints. Be sure that

the units are off and unplugged before
cleaning and that excess cleaning fluid
does not get inside the amplifier. Take

care when cleaning near printed words

not to rub so hard as to remove the
printing.

WIRING FOR DIFFERENT

LINE VOLTAGES

For voltage change information,

contact the factory.

240V OPERATION

Some 220V lines run high, in some

cases close to 240V. This may cause
mechanical noise in the supply chassis if it

is set for 220V. Changing to 240V
operation may solve this problem.

7

Instructions (cont.)

PERFORMANCE AMPLIFIER

ADDITIONAL ACCESSORIES
AND PARTS

Cello Strings

cables are available in pre-made or
custom lengths to provide the optimum in

signal transfer.

Adapters:

available to connect Fischer three pin

connectors (used on all Cello equipment)

to RCA, XLR and Camac as well as other

Fischer type connectors.

Replacement Foam Fan-air Filters

are available in the event yours should

become damaged or lost.

Custom Amplifier DC Cables

available if the supplied length of DC
cables is inadequate due to unusual
amplifier placement. Please be advised
that these are special order items and
subject to certain time and availability
constraints. Requested lengths should
not exceed 20 feet.

CELLO LIMITED WARRANTY
Parts:

Cello warranties all mechanical
parts for five years and electronic parts
for life.

Labor:

distributor except for the following:
Any defective product during the first

year shall be repaired by the distributor
with labor paid by Cello according to fac­tory rates for a given repair.

component interconnect

A full line of adapters is

are

Labor is the responsibility of the

At Cello's discretion, or if the distributor
is unable to perform the repair, the unit
may be returned to the factory for service
using agreed-upon air freight. After
repair, the unit will be returned by the

same carrier or equivalent. During years

2-5, if the distributor is unable to perform

the repair Cello will pay return air freight
from the factory by agreed upon carrier
provided the unit was shipped to the fac-

tory with air freight prepaid.
Cello will not pay freight if units are

returned without a Return Authorization
number (RA#). Cello will not pay freight
if units are found to be in perfect working
order.

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), except for electron-

ic parts which carry a lifetime warranty.

Product Registration & Transferability:

Distributors shall fill out the form on the
outside of the carton when the goods are
delivered to the retailer. The form should

be sent to Cello, Limited. Warranty cards

inside the box shall be completed by the
retailer and customer respectively and
returned to Cello, Limited within 30 days

from the date of the sale to the customer.

All products must be registered. When
sold, new owners must be registered for
the transfer of the warranty to be effected.
All warranties are transferable to any suc­cession of subsequent registered owners.
Please contact you nearest authorized
Cello supplier or the Customer Service
Department at the factory for details of
subsequent owner warranty registration.

Tampering/Abuse/Misuse:

thorized modifications, repairs or tamper­ing, and/or any indications of obvious
owner abuse, negligence or improper
usage, as determined by Cello Limited
shall be grounds to void the warranty.

Service: If you believe your Cello equip­ment is not functioning properly, please
call the Customer Service department at

the factory. If you need to return your
component, you will be given an R/A

(return authorization) number. This num­ber must appear on the outside of the

shipping boxes. Returns without R/A
numbers will not be accepted. Returns
received in original Cello packaging will
be returned in original packing. Returns

received in non-Cello packing will be

returned in new Cello packaging at the

owner's expense. If you need replacement

packing materials, please contact the

Customer Service Department at the factory.

Any unau-

9

PERFORMANCE AMPLIFIER

Electrical

Power Output

Single Amp

Load (Ohms)

8 200
4

2

1

Bridged Set

Load (Ohms) Watts (RMS)

8
4
2

* NOTE: Clipping levels obtained with 1kHz

necessary to alter the AC line in order to provide the current needed to reach

these levels for testing. This does not become a major issue when playing
music, even at continued high volume levels into low impedance loads.

I

MD SMPTE

60Hz & 7kHz
40V output

THD

20Hz - 20kHz
8 & 4 Ohms, 40V output
1

Ohm, 33V output

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Specifications

Rated

Watts (RMS)

400
800

1000

800

1600

3200

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* Clipping @ 1kHz

Watts (RMS)

> 350
> 700

>1000
>1300

Watts (RMS)

>1400
>2800
>4000

continuous sine wave. It may be

08%

<0.1%

<.3%

Frequency Response

Channel Separation

Signal to noise

Input Impedance

Input Sensitivity

Gain

NOTE: All measurements are for one supply, one amp.

(All specifications subject to change without notice)

10

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20kHz

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40kHz

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L - R

40V output

20Hz - 20kHz

Non-inverting

Inverting

40V output, 8 Ohms
200W(RMS)

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-0.8dB

-3.0dB

Infinite

<-105dB

1MOhm
5kOhms

1.485V

28dB

AMPLIFIER

PERFORMANCE AMPLIFIER

Physical Specifications

Height (chassis)
Height (max.)
Width (foothold)
Width (chassis)

Depth (foothold)
Depth (chassis)
Depth (max.*)

Weight: Net

Boxed

SUPPLY

Height (chassis)
Height (max.)
Width (foothold)
Width (chassis)
Depth (foothold)
Depth (chassis)
Depth (max.*)

Weight: Net

Boxed

ENGLISH

7.56 in.

8.44 in.

16.50 in.

17.50 in.

16.2 5in.

17.00 in.

18.05 in.

45 lbs.
60 lbs.

ENGLISH

7.56 in.

8.44 in.

16.50 in.

17.50 in.

16.20 in.

17.00 in.

18.50 in.

45 lbs.
60 lbs.

METRIC

19.2 cm

21.5 cm

42.0 cm

44.5 cm

41.2 cm

42.7 cm

47.1 cm

20.4 kg

27.2 kg

METRIC

19.2 cm

21.5 cm

42.0 cm

44.5 cm

41.2 cm

42.7 cm

47.1 cm

20.4 kg

27.2 kg

Boxed Dimensions:

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.

SUPPLIED CABLES AND CONNECTORS:

LENGTH

DC Cable
AC Mains Cable

NOTE: All measurements for Amplifiers and Supplies are for individual

chassis only.

14.0" H x 25.0" D x 25.0" W

36.5 cm x 63.6 cm x 63.6 cm

ENGLISH

3 ft., 3 in.
7 ft., 4 in.

METRIC

1.0m

2.24m

11

Cello, Ltd.

315 Peck Street, Bldg. 23

New Haven, CT 06513 U.S.A.

203 865-1237 • FAX [phone]