Crown Crown k series User manual

102010-4

9/99

K-Series

Elkhart, IN 46515-1000 U.S.A. Telephone: 219-294-8000.

Fax: 219-294-8329. Trademark Notice:

Balanced Current

Amplifier

™,and

BCA

™are trademarks and

Crown

®is a

registered trademark of Crown International, Inc. Other

trademarks are the property of their respective owners.

Lightning Bolt Symbol:

This symbol is used to alert the

user to the presence of danger-

ous voltages and the possible

risk of electric shock.

Exclamation Mark Symbol:

This symbol is used to alert the

usertomakespecialnoteofim-

portant operating or mainte-

nance instructions found in the

reference manual.

Watch for these symbols:

Page 3

K-Series Balanced Current Amplifier™

Page 2

K-Series Balanced Current Amplifier™

Do not drop or

spill any foreign

(or domestic)

object or liquid

into the K-Series

amplifier.

Clean your

K-Series amp

only with a

damp cloth!

DO NOT BYPASS OR DEFEAT THE

GROUNDING OR POLARIZATION MEANS

USED ON THE K-SERIES AMPLIFIERS.

MAKE SURE ALL BLADES ON THE

POLARIZED POWER PLUG CAN BE

FULLY INSERTED INTO THE EXTENSION

CORD, RECEPTACLE OR OTHER OUTLET

THAT WILL BE USED WITH THE UNIT.

WARNING: Shock hazard. To reduce

the risk of fire or electric shock, do

not expose this unit to rain or mois-

ture. Do not immerse your K-Series

amplifier in any liquid. Do not operate

your amplifier near a pool, bathtub or

other standing water.

Read all safety and oper-

ating instructions before

operating the K-Series

amplifier. Follow all

instructions carefully and

heed any warnings given.

Hi! I'm Mick, Ill be

giving you the de-

tails about your

new K-Series mp!!

Obtain assistance from qualified ser-

vice personnel if any of the following

occurs:

• The power cord or plug has been

damaged in any way.

• Foreign objects or liquid has fallen

into the amplifier enclosure.

• The amplifier has been exposed to

rain or has been partially or totally

immersed in any liquid.

• The amplifier has been dropped or

the chassis has been damaged.

• You notice a marked change in per-

formance, or your K-Series amp oth-

erwise does not appear to operate

normally.

CAUTION:

Do not locate sensitive,

high-gain equipment such

as preamplifiers or tape

decks directly above or be-

low the unit. If an equip-

ment rack is used, we

recommend locating the

amplifier(s) in the bottom of

the rack and the preampli-

fier or other sensitive

equipment at the top.

Friendly Page

of Tips and

Warnings

Keep your K-Series amplifier

away from sources of heat,

such as a radiator or oven.

Do not cover or surround your

amp with material which may

retain heat, such as a

blanket or curtain.

Important:

Driving heavy loads for sustained periods of time

may cause parts of the amplifier’s case to reach

temperatures which will be hot to touch. But don’t

be alarmed.The amplifier’s internal protection

circuitry ensures maximum temperature levels will

remain well below any level that might be

harmful to the amplifier.

Protect the power

cord attached to

your K-Series am-

plifier. Route it to

avoid foot traffic

or other situations

where the cord

might be stretched

or pinched. Pay spe-

cial attention to the

cord connector and

attachment points.

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

Contents

Friendly Page of Tips and Warnings...................... 2

Important Safety Instructions ................................. 4

Unpacking Your

K-Series

Amplifier........................ 6

Quick Start ............................................................ 7

Features ................................................................ 9

1 Welcome............................................................. 10

2 Very Detailed Install............................................. 14

3 Operation............................................................ 21

4 Other Issues........................................................ 26

5 Specifications ..................................................... 31

6 Service................................................................ 36

Illustrations

Typical Stereo Hookup .......................................... 8

1.1 The

K-Series

Amplifier.................................... 10-11

1.2 The Big Picture: Controls, Indicators and

Connectors ................................................... 12-13

2.1 Mounting Dimensions.......................................... 14

2.2 Mono Mode Switches.......................................... 15

2.3 Input Sensitivity Switch........................................ 15

2.4 Typical Input Wiring............................................. 16

2.5 Stereo Output Wiring........................................... 17

2.6 Bridge Mono Output Wiring................................. 18

2.7 Stereo Hookup .................................................... 19

2.8 Bridged-Mono Output Hookup ............................ 19

2.9 “Y” Mono Input Hookup....................................... 20

2.10 “Y” Mono Input / Bridged Output ......................... 20

3.1 Front Panel Indicators & Controls ........................ 21

3.2 Back Panel Controls............................................ 23

3.3 Back Panel Fuse Location................................... 25

4.1 Balanced & Unbalanced Input Wiring ................. 28

4.2 Balanced Input Wiring......................................... 29

4.3 Unbalanced Input Wiring .................................... 30

5.1 Awesome Frequency (Amplitude) Response ...... 35

5.2 Superior Damping Factor .................................... 35

Important Safety Instructions

1) Read these instructions.

2) Keep these instructions.

3) Heed all warnings.

4) Follow all instructions.

5) Do not use this apparatus near water.

6) Clean only with a dry cloth.

7) Do not block any ventilation openings. Install in accor-

dance with the manufacturer’s instructions.

8) Do not install near any heat sources such as radiators,

heat registers, stoves, or other apparatus that produce

heat.

9) Do not defeat the safety purpose of the polarized or

grounding-type plug. A polarized plug has two blades

with one wider than the other. A grounding-type plug has

two blades and a third grounding prong. The wide blade

or the third prong is provided for your safety. If the pro-

vided plug does not fit into your outlet, consult an electri-

cian for replacement of the obsolete outlet.

10) Protect the power cord from being walked on or pinched,

particularly at plugs, convenience receptacles, and the

point where they exit from the apparatus.

11) Only use attachments/accessories specified by the

manufacturer.

12) Unplug this apparatus during lightning storms or when

unused for long periods of time.

13) Refer all servicing to qualified service personnel. Servic-

ing is required when the apparatus has been damaged in

any way, such as power-supply cord or plug is damaged,

liquid has been spilled or objects have fallen into the ap-

paratus, the apparatus has been exposed to rain or mois-

ture, does not operate normally, or has been dropped.

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

Quick Start!

First things first. We know you just

can’t wait to crank up your new

Crown®

K-Series

amplifier. And the

last thing you want to do is dig through

pages of tech-talk to find out where the

“ON” switch is. So that’s why we provided

you with this quick and simple page to get

you up and running right away. Just take a

fewminutestoreadthroughthis—nomorethan

five or ten, max—you’ll be glad you did.

1. Make sure the

K-Series

amp and all other equipment is

turned OFF before you begin wiring. The amp power switch,

which is located on the far right side of the front panel, is

“OFF” when pressed downward.

2. Mount your

K-Series

amp securely in the rack.

3. Connect the left and right inputs coming from your mixer,

preamp, or other processor. You can use either bal-

anced 1/4-inch phone or 3-pin XLR connectors. You

can also choose to run in MONO mode, with either

bridged outputs, “Y” inputs, or both. If so, see the sec-

tions starting on page 14 for further instructions.

4. Connect the output wiring (left and right speakers).

5. Connect your

K-Series

amp and other equip-

ment to the appropriate power source.

6. Turn on your mixer, preamp, signal

processor, or any other equip-

ment in your system EXCEPT

your

K-Series

amplifier. (Remem-

ber: save the best for last.)

7. Make sure the Channel 1 and

Channel 2 level (volume) controls

on your

K-Series

amplifier are

turned all the way down (counter-

clockwise), then flip the power

switch “ON” (press upward).

Unpacking Your

K-Series Amp

Please unpack and inspect your amplifier for any damage that

may have occurred during transit. If damage is found, notify

the transportation company immediately. Only you can initiate

a claim for shipping damage. Crown will be happy to help as

needed. Save the shipping carton as evidence of damage for

the shipper’s inspection.

We also recommend that you save all packing materials so

you will have them if you ever need to transport the unit.

NEVER SHIP THE UNIT WITHOUT THE FACTORY PACK.

FCC COMPLIANCE NOTICE

This equipment has been tested and found to com-

ply with the limits for a Class A digital Device, pur-

suant to Part 15 of the FCC Rules. These limits are

designed to provide reasonable protection against

harmful interference when the equipment is oper-

ated in a commercial environment. This equipment

generates, uses and can radiate radio frequency

energy and, if not installed and used in accordance

with the instruction manual, may cause harmful in-

terference to radio communications. Operation of

thisequipment in aresidential areais likelyto cause

harmful interference in which case the user will be

required to correct the interference at his own ex-

pense.

“The user is cautioned that any changes or modifi-

cations not expressly approved by Crown Interna-

tional could void the user’s authority to operate the

equipment.”

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

Typical Stereo

Hookup

Note: After a two-second delay, the “Enable” light will glow a

bright green to indicate power is on. If no audio signal is

present at the amp, the enable light will then switch to a dim

green.

8. (Now comes the fun!) Supply input, adjust amp levels

and enjoy.

CAUTION: Excessive output levels may toast your speakers.

Crown’s

-Series amplifier has such low distortion, you may

not realize the actual level being reached until it’s too late.

Please exercise caution and drive your speakers responsi-

bly, or at least warn your neighbors!

9. You may notice that your

K-Series

amplifier becomes warm

tothetouch after afewminutesofuse.Don’tbealarmed. This

is the normal operating condition for your

K-Series

amplifier.

The

K-Series

of amplifiers are designed to be convection

cooled, and therefore radiate heat passively to the

enviroment. Refer to page 26 for more details.

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

Fig. 1.1

The K-2 Amplifier

(K-1 Amplifier

appears the same

except for

nameplate)

The

K-Series

amplifiers are also highly energy-efficient—some

of the World’s first “green” amps. As a result, the

K-Series

amps use less electricity (reducing your utility bills) and save

the precious resources of our environment.

And that’s not all! Your

K-Series

amp can drive an amazing

range of loudspeakers, making it one of the most versatile

amplifiers ever. Plus, your

K-Series

has one of our most so-

phisticated (and totally automatic) protection systems, so your

amplifierwill keep working long after otheramplifiers have shut

down. It’s part of our philosophy:

Your show must go on!

This manual will help you correctly set up and use your new

amplifier—we strongly recommend you read all instructions,

warnings and cautions. Also, for your protection, please send

in your warranty registration card today. And save your bill of

sale—it’s your official proof of purchase.

Thank you for choosing Crown! Mick and his team of enthusi-

astic engineers have worked long hours to craft a totally new

kind of amplifier—the

K-Series.

These are the first amplifiers to

incorporate Crown’s patented BCA™ (Balanced Current Am-

plifier™) technology, and we are all very proud to have in-

vented them. Our Balanced Current Amplifier makes use of a

special type of circuitry which allows high levels of power out-

put without all of the associated heat you find in a conventional

amplifier. And that’s very good news for you!

How high is the power output? The

amplifier produces an

impressive 1,500 watts and weighs only 32 pounds, while the

produces a whopping 2,500 watts while weighing only 38

pounds; both without using a cooling fan!* Of course, the ab-

sence of a cooling fan means your amp runs quieter (no fan

noise) and cleaner (no need for filters) and requires very little

maintenance (we

thought

you’d like that).

* 1,500 watts and 2,500 watts total from both channels (for the

and

respectively; 750 and 1,250 watts per channel). See the Specifications sec-

tion for details.

1 Welcome

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

Note: K1 amplifier and CE (European) versions of both amplifiers feature identical front and

back panel layouts except for product nameplates and fuse specifications.

Fig. 1.2

The Big Picture:

Controls,

Indicators &

Connectors

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

3. Set the mono mode switches. Both the Bridge Output

and “Y” input switches should be in the OFF position

when you’re running in Stereo Mode (see Figure 2.2). Ste-

reo Mode allows independent inputs on the right and left

channels to feed separate speakers at the output. It’s the

configuration typically chosen for everyday audio appli-

cations.

Fig. 2.2

Mono Mode

Switches

Fig. 2.3

Input Sensitivity

Switch

Turn the Bridge Output switch to ON to have a single in-

put that feeds to a single output with twice the voltage of

Stereo Mode. Use this configuration if you want to give up

stereo capabilities in order to drive your speakers

louder.

(You might also choose to use this configuration if you are

running a distributed sound system from the

K-Series

amp

)

Turn the “Y” input switch to ON if you want both inputs to

be connected in parallel. Use this configuration if you

want a common audio signal to feed out to two channels,

each having its own level control. You might use this

setup if you’re running to a monitor speaker on one chan-

nel and a main speaker stack on the other channel.

You may also want to configure your system to take ad-

vantage of both the Bridge Output and “Y” input capabili-

ties. This would allow you to have daisy-chained inputs

fed to a double-the-voltage output. (See further instruc-

tions on daisy-chained inputs in the discussion on con-

necting the inputs in step 5 in this section.)

4. Set the Input Sensitivity switches of each channel to

the desired setting (see Figure 2.3). Two choices are

available: 1.4 V for full rated output, or a fixed voltage gain

of 26 dB. (The

K-Series

ship from the factory with default

settings of 1.4 V, which translates to approximately 33 dB

of gain.)

2 Very Detailed Install

Follow these instructions for a detailed explanation of

K-Series

installation procedures and options. If you just want to get up

and running as quickly as possible, see the Quick Start sec-

tion on page 7.

1. Begin with the amplifier turned off and disconnected

from the power receptacle. The

K-Series

power switch

is located on the right side of the front panel; it is OFF

when depressed downward. Equipment that will be con-

nected to the inputs of the amplifier (such as mixers or

preamplifiers) should also be turned off.

2. Mount the amplifier. Your

K-Series

amp is designed to

be mounted in a standard, 19-inch (48.3-cm) equipment

rack (see Figure 2.1). It has been furnished with a conve-

nient, 2-foot-long AC power cord. To meet system compli-

ance, this cord must be plugged into a local,

rack-mounted, commercial grade electrical outlet box.

Extension cords are not to be used. The amp has a

unique front-panel design which provides exceptional air

circulation between

K-Series

amps, which makes it easy

to keep your amplifiers cool. (See the section “You Gotta

Know When To Kool It!” on page 26 for hints on amplifier

cooling.)

Fig. 2.1

Mounting

Dimensions

When mounting your amp in a rack, you should secure

the back of the rack as well as the front. Even though the

amp’s center of gravity is toward the front, securing the

amp at both front and rear will assure that the amp stays

in place, even when the rack is transported.

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

If you are running with both the Y-Input and Bridge Output

switches “ON”, you may choose to make use of the un-

used input connectors as low-voltage daisy-chain out-

puts—perhaps to other amplifiers in your system. For

instance, if you’re running in “Y” mono mode and you

connect the input signal to the Channel 1 XLR connector,

you can use the Channel 2 XLR connector plus the two 1/

4-inch phone plugs for daisy-chained outs. This simplifies

your wiring needs, making good use of all the compo-

nents in your system.

Fig. 2.5

Stereo Output

Wiring

6. Connect the outputs of the

K-Series

amp to your loud-

speakers. If the Bridge Output switch is turned OFF, con-

nect the positive (+) and negative (–) leads of each

loudspeaker to the appropriate Channel 1 and Channel 2

output connectors as shown in Figure 2.5.

Output Wiring Tips

1. To prevent possible short circuits, wrap or otherwise insulate

exposed loudspeaker cable or cable connectors.

2. Donot use connectors thatmight accidentally tie conductors

together when making or breaking the connection

(for example, a standard, 1/4-inch stereo phone plug).

3. Neveruse connectors that could beplugged into AC power sockets.Accidental AC

input will be an electrifying experience for your equipment. But you will find out real

quick if your speakers are any good at 60 Hz!

4. Avoid using connectors with low current-carrying capacity, such as XLRs.

5. Do not use connectors that have any tendency to short.

If the Bridge Output switch is ON, only the Channel 1 in-

put connectors should be used. If only the “Y” input

switch is ON, then either set of connectors can be used.

5. Connect the inputs of the

K-Series

amp to your mixer,

preamplifier, or other equipment ahead of the amp. Two

types of balanced input connectors are provided, allow-

ing you to choose either 1/4-inch phone or 3-pin XLR con-

nectors (see Figure 2.4). You can also choose to use

either balanced or unbalanced wiring. (See the section

Balancing the Line on page 28 for an explanation of bal-

anced vs. unbalanced wiring.)

Input Wiring Tips

1. For all input connectivity, use shielded wire only. Cables with a

foil wrap shield or a high-density braid are superior. Cables with

a stranded spiral shield, although very flexible, will break down

over time and cause noise problems.

2. Try to avoid using unbalanced lines with professional equipment.

If you have no choice, keep the cables as short as possible. (Re-

fer to the section Balancing the Line on page 28.)

3. To minimize hum and crosstalk, avoid running low-level input cables, high-level output

wires and AC power feeds in the same path. Try to run differing signal-cable paths at 90°

to one another. If you must use a common path for all cables, use a star-quad cable for

the low-level signals.

4. Before changing input connectors or wiring, turn the amplifier level controls all the way

down (counter-clockwise).

5. Before changing output connections, a professional will turn the amplifier level down and

the AC power off to minimize the chance of short-circuiting the output.

Fig. 2.4

Typical Input

Wiring

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

Fig. 2.7

Stereo Hookup—

two stacks, one

amp, stereo in,

stereo out.

Fig. 2.8

Bridged-Mono

Output Hookup—

mono or stereo In,

mono out—great for

subs...or when you

want it LOUD!

If the Bridge Output switch is turned ON, connect a mono

load across the red binding posts of each channel as

shown in Figure 2.6. Do NOT use the black binding

posts when the Bridge Output switch is turned on.

Fig. 2.6

Bridge Mono

Output Wiring

Notice that the Channel 1 red binding post is positive (+)

and the Channel 2 red binding post is negative (–) when

the Bridge Output switch is turned on. The black binding

posts should not be used.

Never short or parallel the output channels of a

K-Se-

ries

amplifier to itself or to any other amplifier.

Detailed diagrams of the four possible input-to-output

configurations (Stereo, Bridged-Mono, “Y” Mono, and “Y”

Input to Bridged-Mono) are shown on the following

pages.

7. Turn on all equipment ahead of the amplifier such as

the mixer or preamplifier. Adjust their signal levels to their

optimum “signal to noise” settings.

8. Plug the amplifier into the power receptacle, turn on

the amplifier and adjust its level controls to a desired

setting. See instructions on page 22 if this is the first time

the amplifier is being turned on.

The Next Couple of

Pages Show Some

Typical Hook-up

Options...

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

3 Operation

Operating a

K-Series

amp is really fun!

Indicators

TLC: The TLC (thermal level control) indicators turn on with a

dim glow a little before the amplifier needs help dissipating

heat. This forewarning gives you a chance to turn on a fan or

other auxiliary cooling (if available) or turn down the level con-

trols of the amplifier. If you do neither, the amplifier will auto-

matically begin to protect itself with its TLC protection system

by subtly and dynamically reducing the gain as needed. The

TLC indicators gradually turn brighter as the TLC protection

becomes greater.

Clip: The orange Clip indicators turn on when distortion of any

type becomes audible in the amplifier output.

For the first time in its 50 year history, Crown has added clip

lights to an amplifier. We had resisted this feature in the past

because our IOC system was more sensitive than clip indica-

tors. We know that having good information at the right time is

vital for success in business, and so we felt an indicator telling

you the waveform had just been “clipped” was too little, too

late. But now you have a choice! If you want to know when

you are in trouble, look at the clip light. If you want to know

before you are in trouble, look at the IOC light.

Fig. 3.1 Front Panel Indicators & Controls

Fig. 2.9

“Y” Mono Input

Hookup—Great

for when you want

independent level

controls for

monitors and main

stacks

Fig. 2.10

“

Y” Mono Input to Bridged-Mono Output

Hookup—When you want plenty of power

such as running a sub-bass and you

need to daisy chain the input signal.

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K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

Note: Your amplifier is equipped with a state-of-the-art soft-

start feature so you do not need to delay the turn-on of K-

Series amplifiers in large installations.

4 After the Enable light turns on, test the operating range of

your input by turning up the level of your audio source to the

highest possible operating level.

5S-L-O-W-L-Y turn up the level controls on the front of the am-

plifier until the maximum desired loudness or power level is

achieved. Be prepared for astounding output!

6 Turn down the level of your audio source to its normal range.

InputSensitivity: Theinputsensitivitysettingdeterminestheover-

all gain of the amplifier. Although you might me tempted to config-

ure your amp to get as much gain as possible (after all, you just

paid

lots

of money for this little beauty), you should instead look

at your operating conditions and adjust the input sensitivity

accordingly.

First, check to make sure your mixer or console is being

operatedatoptimumsignal-to-noise,withoutclippingthe

output. (Refer to the owner’s manual for information on

how to check this.) Then, with your amplifier’s input sensi-

tivity set to the 26 dB position, turn up your amp’s level

controls until you achieve the desired level (loudness). If

you turn the level controls all the way up, and it’s still not

loud enough, check the following:

Fig. 3.2 Back Panel Controls

IOC:

The yellow Input/Output Comparator indicators are

super-sensitive distortion indicators that turn on long before

distortion is audible (approximately 1¤30th the level that would

trigger one of the Clip indicators). This circuit compares the

actualwaveforms of the input and output. It immediately alerts

you of any distortion that exceeds 0.05% to provide dynamic

proof of distortion-free performance. The

IOC

indicators in-

clude a pulse-stretching feature that helps make them more

noticeable even with rapid transient signals.

Signal: The green Signal indicators flash dimly when a very

low-level signal (as low as 10 mW) is present in the output.

They flash brightly when a louder signal (at least 1 watt) is

present at the output.

Enable: The green Enable indicator turns on when your

K-

Series

amp has been turned on and has power. When first

turned on, there will be a brief (two second) delay while the

amplifier performs a quick start-up test. Then the Enable indi-

catorwill turn ontoits full brightness. If nosignalis present, the

Enable indicator will switch to a dimmer green.

Controls

Level: You can adjust each channel’s output using the cali-

brated level control on the front of the amplifier. To turn down

the level, rotate the control counter-clockwise. To turn up the

level, rotate it clockwise.

Power: The power switch is located on the front panel so you

can easily turn the amplifier on or off. When the switch is de-

pressed downward, the amp is off. If you ever need to make

any wiring or installation changes, don’t forget to also discon-

nect the power cord. Please follow these steps when first turn-

ing on your amplifier:

1 Turn down the level of your audio source. For example,

set your mixer’s volume to “¥” (off).

2 Turn down the amplifier’s level controls (counter-clock-

wise to 100 dB).

3 Turn on the power switch. The amplifier will go through a

start-up test that lasts just a couple of seconds. After-

ward, the enable indicator beside the switch will turn on

to full brightness.

Page 25

K-Series Balanced Current Amplifier™

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K-Series Balanced Current Amplifier™

Bridge Output (see Figure 2.8): This on/off switch combines the

twoamplifieroutputchannelsintoasinglemonochannelwithtwice

the voltage of the single channels. This means the output will be

much more powerful! It does this by bridging the outputs, and it

requires special loudspeaker wiring. Do not use the black bind-

ing post outputs when the Bridge Output switch is turned on.

Connecting anything to the black binding posts may result in a

visit by the Binding-Post Police. (See Section 2 for more informa-

tion.) When the Bridge Output switch is turned on, only the Chan-

nel 1 level control will work.

“Y” Input (see Figure 2.9): This on/off switch combines the two

amplifier input channels by “Y-ing” or paralleling them together

(See Fig. 2.9). When the “Y” Input switch is turned on, a signal fed

into either input channel will be fed to both outputs and the indi-

vidual level controls of each channel will continue to work inde-

pendently.

Fuses

A fuse is provided to protect the power supplies from excess cur-

rent. It is located on the back panel below the power cord.

K-Series

amplifiers that are configured to use 100-120 VAC power

should use the following fuses: A 20-amp fuse should be used for

K-2

amplifiers and a 15-amp fuse should be used for

K-1

ampli-

fiers.

K-Series

amplifiers that are configured to use 200-250 VAC

power should use the following fuses: A 10-amp fuse should be

used for

K-2

amplifiers and an 8-amp fuse should be used for

K-1

amplifiers.

Fig. 3.3 Back Panel Fuse Location

IMPORTANT: Contact a Crown Service Center or our

Technical Support Group for information on changing fuses.

K1 - Full Power into 8 Ohms

Sensitivity Power at 8 ohms Gain

1.4 V (+5.21 dBu) 350 W 31.55 dB

2.65 V (+10.7 dBu) 350 W 26 dB

K2 - Full Power into 8 Ohms

Sensitivity Power at 8 ohms Gain

1.4 V (+5.21 dBu) 500 W 32.88 dB

3.09 V (+12 dBu) 500 W 26 dB

Note: Bold type indicates selectable option on amplifier.

Note: 0 dB on the mixer = +4 dBu

1) Verify that the mixer is operating at its correct output

level. See if there is a +4/-10 dB switch on the output; if

so, set it to the +4 dB position.

2) Turn the amplifier level controls all the way down

(counter-clockwise). Then, move the sensitivity switch to

the 1.4-V position. This will increase the gain of the am-

plifier; 5.5 dB for the K1 and 7 dB for the K2. Now care-

fully turn the amplifier level controls up (clockwise) to

the desired level (loudness). Take care when you are

adjusting the level controls at this input sensitivity set-

ting. Increasing the input sensitivity of the amplifier may

cause the input stage of the amp to overload, so be pre-

pared to back down the output of the mixer by 1 or 2 dB

if you notice the amplifier’s clip indicators beginning to

flash.

Page 27

K-Series Balanced Current Amplifier™

Page 26

K-Series Balanced Current Amplifier™

Regardless of your operating conditions, the

K-Series

amplifier

only dissipates the same heat as two100-watt lightbulbs. This will

be hot to touch, but even in such extreme conditions, your

K-Se-

ries

amplifier will not suffer any ill effects. That’s because the

K-

Series

amplifiers contain TLC (thermal level control) systems that

willbegintodecreasethe gainoftheamplifieriftheTLCindicators

illuminate and no steps are taken to reduce the input signal or

attemptsmade toimproveaircirculation.Theamplifierwillnot shut

down, you’ll still be rockin’ with plenty of distortion-free decibility!

If you can’t, or don’t want to change the preceding conditions,

two possible alternatives are available to add the necessary

air movement. First, you can add fans to direct air onto any

surface of the amplifier. Second, you can space the amplifiers

in the rack, allowing the top and bottom covers to act as radia-

tors. In extreme conditions, a combination of these two meth-

odsmayberequired,as would beexpectedforproperthermal

functioning of any amplifier.

4 Other Issues

Ya Gotta Know When to Kool It!

Your

K-Series

amplifier has been designed from the

ground up to be a high-output amplifier that is totally

convection cooled—meaning no fan is required. This

goal was achieved through a variety of means:

First, we forgot to include the fan in the bill of materials.

Second, our balanced-current circuitry produces power

much more efficiently than conventional amplifier circuits.

Third, the amplifier case and front panel were designed

for increased airflow and superior heat dissipation.

The smoothly molded front panel was also designed to allow the

centerofgravitytobemovedforward,placingitclosertoitsmount-

ing axis. While providing strength and rigidity, the die-cast panel

also protects the front panel controls and indicators from inadvert-

ent abuse.

Until now, all professional audio systems had either internal or ex-

ternal auxiliary air systems facilitating the cooling of the electron-

ics. Withthe

K-Series,

wehavemadefansunnecessaryfornormal

operation!

If you are operating the

K-Series

amp

in very high ambient tem-

peratures, or if you notice theTLC indicators starting to illuminate,

do not despair! Typically, modest amounts of air movement will

enable your amp

to dissipate any excessive heat and regain its

normal composure.Due to the wide range of operating conditions

presentinthe field, each installationneeds to be consideredinde-

pendently for optimum thermal operation. If your TLC indicators

illuminate, consider the following possible causes:

1) Insufficient air movement.

2) Overdriving of the input stage (severely into clip).

3) Very low-impedance loads.

4) High ambient temperatures.

Normally, two or more of these situations must be present in order

to cause illumination of the TLC LEDs.

Page 29

K-Series Balanced Current Amplifier™

Page 28

K-Series Balanced Current Amplifier™

Fig. 4.2 Balanced Input Wiring

Hum and Buzz Tips

1. It is imperative that all of your electrical equipment share the

same power ground reference.

2. Unless you are interfacing to a microphone, the shield of the

cable should be connected only at one end. (See Fig. 4.2.)

3. Do not pass signal ground between electrical components in a grounded source

system

4. Ifyou wish to avoid groundloops, it doesn’t matter ifyoulift the input oroutputsignal

ground for your system topology, just be consistent. Personally I prefer to lift the

input signal ground and it has always been successful...so far!

5. NEVER use a ground lift adapter to lift the power ground on a 3-wire AC cord; this is

not its intended purpose. It is better to have it SAFE than SILENT!! Look for the true

source of the noise.

6. Even when interfacing to an unbalanced load, it is preferable to use two-conductor

shielded cable.

7. Get rid of the lighting company!

Check Figure 4.2 to see if your

cable has been wired with the

proper shield and ground connec-

tion. If the cabling is incorrect, you

may be able to avoid the ground

loop (and associated hum) by plug-

ging all of your equipment into the

same AC circuit (on the same

breaker). If this is impractical, you

will need to fix the cable to match

the appropriate illustration. Or you

may want to simply replace the of-

fending cable with a commercially

manufactured cable of the appro-

priate type.

Fig. 4.1

Balanced &

Unbalanced

Input Wiring

Balancing the Line

A balanced audio circuit typically will have both positive (+)

and negative (–) legs of the circuit that are isolated from the

ground circuit. These balanced legs exhibit identical imped-

ance characteristics with respect to ground, and may also

carry the audio signal at the same level, but with opposite po-

larities. This results in a line that offers excellent rejection of

unwanted noise.

On the other hand, an unbalanced circuit usually holds one

leg at ground potential, while the second leg is “hot.” Unbal-

anced line is less expensive, but is much more susceptible to

noise, and is not usually used in professional applications. For

the cleanest signal, without unwanted hum and buzz, bal-

anced line is always recommended. It is especially helpful if

you have a long cable run (over 10 feet (3 m)), since noise is

easily introduced into long, unbalanced lines.

Getting Rid Of Dr. Hum and Mr. Buzz

If you have noticeable hum or buzz in your system, you may

want to check your cable connections to see if the unwanted

noise is being introduced via a ground loop. To determine the

proper wiring, first check whether the output from your source

is unbalanced or balanced (if you don’t know, refer to the unit’s

back panel or instruction manual). If the source is balanced,

refer to Figure 4.2; if it is unbalanced refer to Figure 4.3. Next,

determine if the source’s power cable is floating (ungrounded,

2-prong) or grounded (3-prong). Finally, if the source in unbal-

anced, check the type of wiring: twin-lead or single coax.

Page 31

K-Series Balanced Current Amplifier™

Page 30

K-Series Balanced Current Amplifier™

5 Specifications

Note: All specifications relate to both the K1 and K2 amplifiers

in both 50- and 60-Hz versions, unless noted otherwise.

Performance...Just How Good Is It?

Frequency Response: ±0.25 dB from 20 Hz to 20 kHz. The

frequency response is band limited with an 8-Hz double-

integrated 3rd-order Butterworth high-pass filter and a 30-kHz

7th-order Gaussian low-pass filter. Optional Aqua-sediment fil-

ter available at your local hardware store. (See Figure 5.1.)

Power Output per channel at 1 kHz with both channels

driven to 0.1 % or less True THD:

K2: 1,250W @ 2 ohms; 800W @ 4 ohms; 500W @ 8 ohms;

Bridged Mono, 2,500W @ 4 ohms.

K1: 750W @ 2 ohms; 550W @ 4 ohms; 350W @ 8 ohms;

Bridged Mono, 1500W @ 4 ohms.

Signal to Noise (A-weighted): >100 dB below rated power.

Voltage Gain,

All Models: 20:1 at maximum level position (26 dB)

K1: 37.8:1 or 31.5 dB at 1.4-volt sensitivity (8 ohms)

K2: 45.1:1 or 33.1 dB at 1.4-volt sensitivity (8 ohms)

Damping Factor: GREAT! (>3,000 from 10 to 400 Hz).

(See Figure 5.2.)

LineVoltageRequirements:Universal power sup-

plycanbeconfiguredto operate with 100,120, 200,

220, 230, 240, 250 VAC at 50 or 60 Hz. Adapters are

acquired through an Authorized Service Center.

Controls...How To Turn It On and Off

Level: A calibrated rotary level control for each channel lo-

cated on the front panel.

Power: An on/off rocker switch located on the front panel.

Input Sensitivity: A two-position switch for each channel lo-

cated on the back panel near each channel’s input connec-

tors. Can be set to 1.4 V for full output into an 8-ohm load or a

fixed voltage gain of 26 dB.

Fig. 4.3 Unbalanced Input Wiring

A couple more

wiring iagrams...

Page 33

K-Series Balanced Current Amplifier™

Page 32

K-Series Balanced Current Amplifier™

Input Impedance: Nominally 20 k ohms, balanced. Nominally

10 k ohms, unbalanced.

Input Sensitivity: 1.4 voltsforstandard1-kHzpower, or26 dB

gain.

Output Connectors: Two sets of color-coded binding posts

for banana plugs, spade lugs or bare wire (European models

are fruit-phobic and do not accept banana plugs).

DC Output Offset: ±10 millivolts.

Output Signal

Stereo: Unbalanced, two-channel.

Bridge-Mono: Balanced, single-channel. Channel 1 controls

are active; Channel 2 should be turned down.

Protection, Dont leave home without it!

K-Series

amplifiersareprotectedagainst shorted, open ormis-

matched loads; overloaded power supplies; excessive tem-

perature, chain destruction phenomena, input overload

damage and high-frequency blowups. They also protect loud-

speakers from input/output DC, DC offset and turn-on/turn-off

transients.

TLC protection circuitry protects the amplifier from excessive

heat by subtly and dynamically reducing the gain only when

necessary to reduce heat levels. Transformer overheating (an

extremely unlikely event) will result in a temporary shutdown;

when it has cooled to a safe temperature, the transformer will

automatically reset itself. Controlled slew rate voltage amplifi-

ers prevent RF burnouts, and input overload protection is pro-

vided by the input current limit.

Out-of-band low-pass and high-pass filter protect the amplifier

and loads from subsonic frequencies below 8 Hz and ultra-

sonic frequencies above 30 kHz.

Turn On: State-of-the-art “soft start” feature prevents the am-

plifier from drawing a large inrush current when it is first turned

on and no dangerous artifacts are produced by the amplifier.

(However it is recommended that all equipment ahead of the

amplifier be turned on first since they may produce turn-on

transients.)

Bridge Output: An on/off switch located on the back panel

between the input connectors which, when turned on, bridges

the two output channels for twice the output voltage..WATCH-

OUT SPEAKERS!!

“Y”Input:Anon/offswitch locatedonthebackpanelbetween

the input connectors which, when turned on, parallels the two

input channels.

Indicators

TLC: ATLC(thermal level control) LED for each channel which

turns on with a dim glow shortly before the amplifier needs

help dissipating heat. (See Pg. 21.)

Clip: An orange LED for each channel which turns on when

distortion of any type becomes audible in the amplifier output.

(See Pg. 21.)

IOC:

A yellow LED for each channel which serves as a distor-

tion indicator. The

IOC

indicators include a pulse-stretching

feature that helps make them more noticeable even with rapid

transient signals. (See Pg. 22.)

Signal: A green LED for each channel which flashes dimly

when a very low-level signal (as low as 10 mW) is present in

the output. They flash brightly when a louder signal (at least 1

watt) is present at the output.

Enable: AgreenLEDthatturnsonwhenthe amplifierhasbeen

turned on and has power. When first turned on, there will be a

brief two-second delay while the amplifier performs a quick

turn-on diagnostic. Then the Enable indicator will turn on to its

full brightness. If no signal is present, the Enable indicator will

switch to a dim level.

Input/Output (Spaghetti Control)

Input Connectors: One balanced ¼-inch phone jack and one

3-pin female XLR connector for each channel.

Input Stage: Inputis electronicallybalanced and employspre-

cision 1% resistors.

Page 35

K-Series Balanced Current Amplifier™

Page 34

K-Series Balanced Current Amplifier™

Fig. 5.1

Awesome Frequency (Amplitude) Response

Fig. 5.2

Superior Damping Factor Provides

Best Bass Control in the Industry!

Test of K2 Amp

Serial Number 106390!!

0.0

6.0

-10.0

-20.0 10 100 1 K 10 K 100 K

FREQUENCY (Hz)

DAMPING

100 1000

100

1,000

10,000

100,000

FREQUENCY (Hz)

MA-2400

Brand X 001

Construction

Beautiful cast-aluminum front panel from hand-crafted mold.

Lovingly coated with the most durable powder coat. Front

panel labels are painstakingly printed in color on Lexan for

durabilityandfingerprint resistance(fullychocolateproof).Alu-

minum chassis with durable black finish.

Cooling: High-performance passive convection cooling sys-

tem allows the amplifier to drive 2-ohm loads to high music

sound levels (6 dB into clip) in a 40° C (104° F ) ambient envi-

ronment .

Dimensions:Standard 19-inch (48.3-cm) rack mount width

(EIA RS-310-B), 3.5-inch (8.9-cm) height and 16-inch (40.6-

cm) depth behind front mounting surface.

Weight: The K2 weighs a mere 38 pounds (17.3 kg). The K1

weighs a mere 32 pounds (14.6 kg). Center of gravity approxi-

mately 6 inches (15.2 cm) behind front mounting surface.

Page 37

K-Series Balanced Current Amplifier™

Page 36

K-Series Balanced Current Amplifier™

Your repairedunit will be returned via UPS ground.Pleasecon-

tact us if other arrangements are required.

Factory Service Shipping Instructions:

1 When sending a Crown product to the factory for service,

be sure to fill out the service information form that follows

and enclose it inside your unit’s shipping pack. Do not

send the service information form separately.

2 To ensure the safe transportation of your unit to the fac-

tory, ship it in an original factory packing container. If you

don’t have one, call or write Crown’s Parts Department.

With the exception of polyurethane or wooden crates, any

other packing material will not be sufficient to withstand

the stress of shipping. Do not use loose, small size

packing materials.

3 Do not ship the unit in any kind of cabinet (wood or metal).

Ignoring this warning may result in extensive damage to

the unit and the cabinet. Accessories are not needed—

do not send cables and other hardware. Do not send this

instruction manual, if we forget what we said, we have du-

plicates!

If you have any questions, please call or write the Crown Tech-

nical Support Group.

Always use the

original factory

packing to

transport

the unit.

CrownAudio

Technical Support / Factory Service

Plant 2 SW, 1718 W. Mishawaka Rd., Elkhart,

Indiana 46517 U.S.A.

Telephone:

219-294-8200

800-342-6939 (North America,

PuertoRico,and Virgin Islands only)

Facsimile:

219-294-8301 (Technical Support)

219-294-8124 (Factory Service)

Fax Back:

219-293-9200 (North America only)

800-294-4094 (North America only)

219-294-8100 (International)

Internet:

http://www.crownaudio.com

6 Service

Your amplifier should only be serviced by a fully trained techni-

cian at an authorized service center.

CAUTION: To prevent electric shock, do not remove covers.

No user serviceable parts inside. Refer servicing to a quali-

fied technician.

Worldwide Service

Servicemaybe obtainedfroman authorizedservicecenter.(Con-

tact your local Crown/Amcron representative or our office for a list

of authorized service centers.) To obtain service, simply present

the bill of sale as proof of purchase along with the defective unit

to an authorized service center. They will handle the necessary

paperwork and repair.

Remember to transport your unit in the original factory packing!

North American Service

Service may be obtained in one of two ways: from an authorized

service center or from the factory, but not your local quick-lube

center! You may choose either. It is important that you have your

copy of the bill of sale as your proof of purchase.

Service at a North American Service Center

This method usually saves the most time and effort. Simply

present your bill of sale along with the defective unit to an autho-

rized service center to obtain service. They will handle the nec-

essary paperwork and repair. Remember to transport the unit in

the original factory packing. A list of authorized service centers in

your area can be obtained from our Technical Support Group.

Factory Service

To obtain factory service, fill out the service information page

found in the back of this manual and send it along with your proof

of purchase and the defective unit to the Crown factory.

For warranty service, we will pay for ground shipping both ways

in the United States. Contact Crown Factory Service or Technical

Support to obtain prepaid shipping labels prior to sending the

unit. Or, if you prefer, you may prepay the cost of shipping, and

Crown will reimburse you. Send copies of the shipping receipts

to Crown to receive reimbursement.

WORLDWIDE

SUMMARY OF WARRANTY

The Crown Audio Division of Crown International, Inc., 1718 West Mishawaka Road,

Elkhart, Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL PURCHASER and

ANY SUBSEQUENT OWNER of each NEW Crown1product, for a period of three (3)

years from the date of purchase by the original purchaser (the “warranty period”) that

thenew Crown product is freeof defects in materialsand workmanship, and we further

warrantthenew Crownproductregardlessof thereasonfor failure,exceptas excluded

in this Crown Warranty.

Note: If your unit bears the name “Amcron,” please substitute it for the name “Crown”

in this warranty.

ITEMS EXCLUDED FROM THIS CROWN WARRANTY

ThisCrown Warranty isin effect only for failureof a new Crown productwhich occurred

within the Warranty Period. It does not cover any product which has been damaged

because of any intentional misuse, accident, negligence, or loss which is covered

underanyof yourinsurancecontracts.This CrownWarrantyalsodoesnotextend tothe

new Crown product if the serial number has been defaced, altered, or removed.

WHAT THE WARRANTOR WILL DO

We will remedy any defect, regardless of the reason for failure (except as excluded),

by repair, replacement, or refund. We may not elect refund unless you agree, or unless

we are unable to provide replacement, and repair is not practical or cannot be timely

made. If a refund is elected, then you must make the defective or malfunctioning

product available to us free and clear of all liens or other encumbrances. The refund

will be equal to the actual purchase price, not including interest, insurance, closing

costs, and other finance charges less a reasonable depreciation on the product from

the date of original purchase. Warranty work can only be performed at our authorized

servicecenters. Wewillremedythe defectandship theproduct fromtheservice center

withina reasonable timeafter receipt of thedefective product at ourauthorized service

center.

HOW TO OBTAIN WARRANTY SERVICE

You must notify us ofyour need for warranty service not later thanninety (90) days after

expiration of the warranty period. All components must be shipped in a factory pack.

Corrective action will be taken within a reasonable time of the date of receipt of the

defective product by our authorized service center. If the repairs made by our

authorized service center are not satisfactory, notify our authorized service center

immediately.

DISCLAIMER OF CONSEQUENTIAL & INCIDENTAL DAMAGES

YOU ARE NOT ENTITLED TO RECOVER FROM US ANY INCIDENTAL DAMAGES

RESULTING FROM ANY DEFECT IN THE NEW CROWN PRODUCT. THIS INCLUDES

ANY DAMAGE TO ANOTHER PRODUCT OR PRODUCTS RESULTING FROM SUCH

A DEFECT.

WARRANTY ALTERATIONS

No person has the authority to enlarge, amend, or modify this Crown Warranty. This

CrownWarrantyisnot extended by the lengthof timewhich youaredeprived of theuse

of the new Crown product. Repairs and replacement parts provided under the terms

of this Crown Warranty shall carry only the unexpired portion of this Crown Warranty.

DESIGN CHANGES

Wereservetherighttochangethedesignofanyproductfromtimetotimewithoutnotice

and with no obligation to make corresponding changes in products previously

manufactured.

LEGAL REMEDIES OF PURCHASER

No action to enforce this Crown Warranty shall be commenced later than ninety (90)

days after expiration of the warranty period.

THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERS

CONTAINED IN THIS MANUAL FOR CROWN PRODUCTS. 9/90

THREE YEAR

FULL WARRANTY

YEAR

Telephone: 219-294-8200. Facsimile: 219-294-8301

NORTH AMERICA

SUMMARY OF WARRANTY

The Crown Audio Division of Crown International, Inc., 1718 West Mishawaka Road,

Elkhart, Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL PURCHASER and

ANY SUBSEQUENT OWNER of each NEW Crown product, for a period of three (3)

years from the date of purchase by the original purchaser (the “warranty period”) that

the new Crown product is free of defects in materials and workmanship. We further

warrantthenew Crownproductregardlessofthe reasonfor failure,exceptas excluded

in this Warranty.