Krell Industries Power Amplifier KAV-150a Quick start guide

TheLeaderin AudioEngineering KAV-150a
PowerAmplifier
Instructions for Use,v 98.0
Owner’s Reference

Contents
KAV-150a
PowerAmplifier
Krell®Industries,Inc.
45 Connair Road
Orange, CT 06477-3650 USA
TEL [phone]
FAX[phone]
E-MAILkrell@ krellonline.com
WEBSITE www.krellonline.com
INTRODUCTION
UNPACKING
PLACEMENT
CabinetryConsiderations
ACPowerGuidelines
CONNECTINGTHE KAV-150a
TO YOURSYSTEM
Input andOutputConnections
Configuring the KAV-150a
for BridgedOperation
AMPLIFIER OPERATION
On/Off andStand-byOperation
SystemNoise Considerations
WARRANTY
RETURNAUTHORIZATION
PROCEDURE
SPECIFICATIONS
Page
4
4
5
5
6
6
6
7
8
9
Back Cover
©1998byKRELL
®
Industries,Inc.All rightsreserved P/NI960101900088

CEMarking
This product complieswith the EMCdirec-
tive (89/336/EEC) and the low-voltage
directive (73/23/EEC).
Introduction
Thankyoufor your purchaseof the Krell
®
KAV-150a Power Amplifier. The name
Krell ®has alwaysrepresentedcomponents
that are the premier performersin their
product categories. TheKAV-150apower
amplifiercontinuesin this Krell®tradition
TheKAV-150ais a stereo amplifier that
maybe bridged into monauraloperation.
Designed as a compact componentwith
exceptional sound, the KAV-150amaybe
interfaced easily into multi-amplifier sys-
temsusingthe 12V trigger andthe bridg-
ing capability. TheKAV-150ausesproven
Krell®circuitsbuilt with thesamehighqual-
ity resistors, outputdevices,andinternal
electrical componentsusedin all other
Krell®products. Frominput to output, the
KAV-150ausesdiscrete, fully complemen-
tary circuitry. All circuits upto the driver
stage operate in pure Class A. The
KAV-150a employs a wide bandwidth
designwith a verylownegativefeedbackfor
sonic accuracy throughout the frequency
spectrum.
This owner’s reference manualcontains
important information on the placement,
installation, andoperationsof theKAV-150a.
Pleasereadthis information carefully. A
thorough understandingof these details
will helpinsuresatisfactory operationanda
long life for the KAV-150aandrelated sys-
tem components.
TheKAV-150ais backedby a comprehen-
sive customersatisfaction policy andone
of the mostadvancedservice facilities in
the industry. For detailed information on
the termsandconditions of service, please
consult your warrantyregistration card, or
contactyourdealer, distributor, or Krell
®.
Unpacking
1. Openthe boxandremovethe top layer of
foam.Youwill seetheseitems:
1 KAV-150a
1 ACpowercord
2sparespeakerfuses
1 packetcontaininganintroductory
letter fromDanD’Agostino,C.E.O.,
the Owner’sReferenceandthe
WarrantyRegistration Card
Note
ff anyof theseitemsarenotincluded,please
contactyourauthorizedKrel/~ dea/eror dis-
tributor immediate/yfor assistance.
2. Carefully removethe unit andacces-
sories fromthe box. Removethe protec-
tive plastic wrapfromtheunit.
Note
Saveall packingmaterials, ff youmust
ship your KAV-150ain the future, repack
theunit in its original packagingto prevent
transit damage.
THERE ARE NO USER-SERVICEABLE
PARTSINSIDE ANY KRELL
® PRODUCT
Pleasecontactyourauthorizeddealer,
distributor, or KrelP, if youhaveany
questionsnot addressedin this refer-
ence manual.
KRELL® KAV-150a English Page3 of 12

Placement
WARNING
Theamplifier mustnot be locatedwhereit
couldbe exposedto dripping or splashing
fluids.
Beforeyouinstall the KAV-150ainto your
system,reviewthe following guidelines to
choosethe location for the KAV-150a.This
will facilitateaclean,trouble-freeinstallation.
TheKAV-150adoesnot require any type of
specialrackor cabinetfor installation.Forthe
dimensions of the KA V- 150a, see
Specificationsonpage10.
PlacetheKAV-150aamplifier ona firm level
surfaceawayfromdirt or moisture.Ideally,
the amplifier shouldbeplacedasclose to
the speakersas possible. Runlong bal-
ancedinterconnect cablesto the amplifier
andkeepthe speakercablelength to a min-
imum.Speakercable adds impedanceto
theloadtheamplifier mustdrive, regardless
of thecable’sgauge.All KrelPamplifierswill
drive the lowestimpedanceswith ease,but
whenimpedance is added due to long
cablelengths, amplifier poweris wastedin
the cable. Longspeakercablesreducethe
maximumpowerthat can be delivered to
the speakers.
CABINETRY CONSIDERATIONS
TheKAV-150aamplifier can becomequite
warmundernormaloperation. Install the
KAV-150ain a location that providesunob-
structedventilation.
IMPORTANT
Theventilation grids ontopof theKAV- 150a
needto beunobstructedat all timesduring
operation. Donot place flammablematerial
on top of or beneath the KAV-150a.For
installation inside cabinet~extra ventila-
tion maybe necessary. Makesure the
KAV-150ahas adequateair circulation.
Generallytwo inchesof clearanceon each
side of the amplifier andeight inches of
clearanceabovethe amplifier will provide
adequate ventilation. In more extreme
instances, small fans can aid in removing
excessheat from internal spaces.Contact
yourdealer, distributor, or Krell®for more
information.
AC POWERGUIDELINES
For best performance, Krell ®recommends
using a dedicatedACpowerline rated at a
minimumof fifteen ampswith the KAV-150a
amplifier. TheKAV-150aamplifier should
only be operatedwith the powercord sup-
plied. Pleaseconsultyourdealer,distributor,
or Krell®beforeusinganydevicesdesigned
to alter or stabilize the ACpowerfor the
KAV-150a.
Page4 of 12 English KRELL® KAV-150a

Connectingthe KAV-150a
to YourSystem have6dBmoregain than single-ended
connections.Whenlevel matchingis crit-
ical, keepthis specificationin mind.
WARNING
Whenmakingconnections to this compo-
nent or any other, makesure the power
amplifieris off andthepreamplifieris in the
muteor stand-bymode.Makesure all cable
terminationsareof thehighestquality, free
fromfrayedends,shorts,orcoldsolderjoints.
INPUT AND OUTPUTCONNECTIONS
Topreventthe introduction of humor other
noiseinto the system,organizeall wiring
betweenthe KAV-150aand other system
componentsneatly. Separate ACwires
fromaudiocables.
1. Connectthe cablesfrom your speakers
to theoutputterminalsof theamplifier.
TheKAV-150aamplifier utilizes five-
waybinding post speakerterminals for
theleft andright channels.Thespeaker
terminalsacceptspadelugs, barewire,
bananaplugs, or pins. Thered termi-
nals are usedfor positive connections
andthe blackterminalsareusedfor the
negativeconnections.
2. Connectthe interconnect cables from
yourpreamplifierto theinputterminalsof
theamplifier.
TheKAV-150aamplifier is equipped
with balancedandsingle-endedinputs.
Thebalancedinputs usethree pin XLR
connectorsandthe single-endedinputs
use RCAconnectors. Krell ® recom-
mendsthe use of balancedintercon-
nects. Balancedinterconnectsnot only
havethe ability to minimizesonicloss
but alsohaveimmunityto inducednoise,
especiallyfor installations usinglong
cable lengths. Balancedconnections
WARNING
Useonlyoneset of inputsto theamplifierat
a time. TheKAV-150aamplifier is shipped
with shortingpins in the XLRinputs. These
pins shouldremainin the XLRinputs if the
KAV-150aamplifier is operatingin the sin-
gle-endedmode.Whenthe shorting pin is
inserted, pins 1and3 areshortedtogether.
Theshorting pins mustbe removedto con-
nect the KAV-150aamplifier for balanced
operation.
The XLR pin
below:Pin1
Pin 2
Pin 3
configuration is described
Ground
Non-inverting(0
°)
Inverting(180
°)
Connectthe receptacle endof the AC
powercordto the IECpowerconnectorin
the backpanelof the KAV-150a.Connect
the ACpowercordwall pluginto a stan-
dardACwalloutlet.
4. Theamplifier is nowreadyfor operation.
SeeAmplifier Operation, on page6.
12 VDCREMOTEPOWERIN
This input accepts 12 volt poweron/off
signals from other Krell ®components,as
well as from other devices that incorpo-
rate a 12volt poweron/off trigger output.
This allows for remoteturn on/off of the
KAV-150awith the poweractivation of
anotherKrell ®componentas well as with
other components used in a custom
installation.
KRELL®KAV-150a English Page5 of 12

12 VDC REMOTEPOWEROUT
Thisoutput sends12volt poweron/off sig-
nals to other Krell®components,aswell as
other devicesthat incorporate a 12 volt
poweron/off trigger input. This allowsfor
remoteturn on/off of the KAV-150awith the
poweractivation of anotherKrell®compo-
nent as well as with other componentsused
in a custominstallation.
Note
Consu/tthe owner’smanua/of any device
usedin a custominsta//ation to take furl
advantageof the remotecapabi/ity of the
KAV-150a.
CONFIGURING THE KAV-150a
FOR BRIDGED OPERATION
TheKAV-150amaybe configured to operate
in abridgedmode.Toimplementthis configu-
ration:
1. Turnthe KAV-150aoff.
2. Locatethe red switchonthe backof the
amplifier andslide it fromthe NORMAL
position to the BRIDGEDposition. The
numera/2 will appearonthe switch,when
theswitchis in the BRIDGEDposition.
3. Connectthe interconnect cable to the
BRIDGEDinput, either balancedvia the
XLRconnectoror single-endedvia the
RCAconnector. Donot use both inputs
simultaneously. Connectthe speaker
cablesto the speakerterminalslabeled
BRIDGED(-)and BRIDGED(+).The
lifier is nowreadyfor bridgedoperation.
Amplifier Operation
It is easyto understandtheoperationof the
KAV-150aamplifier. However,great care
needsto beexercisedwhenoperatinga sys-
temthat includes the KAV-150a,becauseof
the amplifier’s enormouspoweroutput.
Switching betweenactive sourceswithout
mutingthe preamplifier output, or bump-
ing/miscuinga cartridge, cangeneratelarge
transients at lowfrequencies.TheKAV-150a
amplifier maygenerateenoughpowerwith
thesetransients to .damagemostloudspeak-
ers. All switchingof sourcesshouldbedone
withthepreamplifierleveleithermutedorfully
attenuated.Donotchangeinputsto theampli-
fier whiletheamplifieris on.
Note
Caremustbe takenwhensetting high p/ay-
back leve/s. Becauseof their tremendous
reserve of c/ean power,Kre//~ amp/ifiers
can safe/y drive speakersto higher sound
pressure /evels than other amplifiers.
A/waysturn the/eve/downat the first sign
of speakerdistress.
ON/OFF AND STANDBY OPERATION
Whenpoweringup any system, amplifiers
shouldalwaysbeturnedonlast andturnedoff
first.
1. Pressthe powerbuttononthe front panel
of the KAV-150aPowerAmplifier.Youwill
heara click. Theamplifier is readyfor
operation.
2. Withthe systempreamplifier in the mute
position,orthevolumecontrolfully atten-
uated, select a source.Turnthe volume
controlupto thedesiredlisteninglevel.
3. When.turning the systemoff, lowerthe
volumeof the systempreamplifier com-
pletely or placeit into themuteor stand-
byposition. TurntheKAV-150aoff. It is
nowsafeto tumoff therest of thesystem.
Page6 of 12English KRELL®KAV-150a

SYSTEM NOISE CONSIDERATIONS
ACgrounding becomescritical whencon-
nectinghigh performanceaudiocomponents.
Whenmixing and matching audio compo-
nents,eachwith their owngroundpotential, a
low frequencyhummayoccurin oneor both
speakers.Thisoftenoccurswhenintroducing
a newcomponentinto a system.
If there is a low frequencyhumemanating
from the speakers whenthe KAV-150a
amplifier is placedinto the system,follow
these simpletroubleshooting steps before
contactingyourauthorizedKrelPdealer,dis-
tributor,orKrell®:
1. Checkall input andoutput connections,
makingsure theyare of soundconstruc-
tion. Withtheamplifieroff, removethein-
=
terconnectwiring andturn the amplifier
on.If thehumdisappears,turn the ampli-
fier off andreinsert oneof theintercon-
nectcables.Thenturn theamplifier back
on. If the humreappearswith oneor both
interconnectsreinserted, there maybea
defective cable. Havethe interconnect
cabling checkedbeforeproceeding.
If the interconnectsproveto be sound,
youmaybe experiencinga groundloop.
Thiscanoften beeasily eliminated.Con-
tact yourauthorizedKrelPdealer,distrib-
utor,or Krell
®.
KRELL®KAV-150a English Page7 of 12

Warranty
Krell® warrantsthis productto befree from
defects in material or workmanshipfor a
periodof five yearsfor circuitry andthree
years for all mechanicalcomponentsfrom
the original date of purchase.Shouldthis
productfail to performat anytime during
thewarranty,Krell®will repairit at nocost
to the owner,exceptas set forth in this
warranty. Transferof warrantyto a second
owneroccurs automatically. Pleasecon-
tact Krell ®to havethe nameon the war-
ranty changed.Transfer of warranty does
not extendthe durationof the original war-
rantyperiod.
Note
This warranty doesnot apply to damage
causedby acts of Godor nature.
Thewarrantyperiod beginson the date of
retail purchaseasnotedontheretail sales
slip providedbyanauthorizedKrell®deal-
er or distributor, or onthewarrantyregis-
tration cardsentto Krell®.In theeventthat
an adequateproof of purchase date is
unavailable,the warrantyperiodwill begin
on the date the product wasoriginally
shipped from the factory. Thewarranty
describedin this paragraphshall bein lieu
of anyother warranty,expressor implied;
including, but not limited to, anyimplied
warrantyof merchantabilityor fitness for a
particular purpose. There are no war-
ranties which exceed beyond those
describedin this document.If this product
doesnot performas warrantedherein, the
owner’ssole remedyshall be repair. In no
eventwill Krell®beliable for incidentalor
consequential damagesarising from pur-
chase,use,or inability to usethis product,
evenif Krell®hasbeenadvisedof the pos-
sibility of suchdamages.
Thewarrantyfor this Krell® productis valid
only in the country to whichthe product
wasoriginally shipped,throughthe autho-
rized Krell®distributor for that country,and
at thefactory. Theremayberestrictions on
or changesto Krell’s warranty becauseof
regulations within a specific country.
Pleasecheckwith your distributor for a
completeunderstandingof the warrantyin
your country.
Freightto thefactoryis yourresponsibility.
Return freight within the United States
(U.S.A.)is includedin the warranty.If you
havepurchasedyour Krell ® product out-
side the U.S.A. andwish to haveit ser-
vicedat the factory, all freight andassoci-
ated charges to the factory are your
responsibility. Krell®will payreturnfreight
to the U.S.A.-basedfreight forwarder of
your choice. Freight andother chargesto
ship the productfromthe freight forwarder
to youarealso yourresponsibility.
Theoperating voltage of this product is
determinedat the factory andcanonly be
changedby an authorizedKrell®distributor
or at the factory. Thevoltagefor this prod-
uct in the U.S.A.cannotbechangedfor six
monthsfrom the original purchasedate.
Anyunauthorized voltage conversion,
disassembly, componentreplacement,
perforation of chassis, updates, or
modifications performedto the product
will voidthe warranty.
Page8 of 12English KRELL®KAV-150a

ReturnAuthorization
Procedure
IMPORTANT
ff youbelievethere is a problemwith your
component,pleasecontactyourdealer, dis-
tributor, or theKrell®factoryto discussthe
problembefore you return the component
for repair. To expedite service, you may
wish to completeande-mail the Service
RequestFormon our website at:
ww~.krellonline. com
Toreturna productto Krell®,pleasefol-
low this procedureso that wemay
serveyoubetter:
1. Obtain a Return Authorization Number
(R/A number) and shipping address
fromthe Krell®ServiceDepartment.
2. Insureandacceptall liability for lossor
damageto the product during shipment
to theKrell®factoryandprepayall ship-
ping charges. Theproduct mayalso be
handdeliveredif arrangementswith the
Service Departmenthavebeenmadein
advance.Proof of purchasemaybe re-
quiredfor warrantyvalidationat thetime
of handdelivery.
3. Usethe original packagingto insure the
safetransit of theproductto thefactory,
dealer, or distributor. Theuseof any
packagingmaterialotherthantheoriginal
packagingmaterials is not recommend-
ed.KrelPmay,at its discretion, returna
product in newpackagingandbill the
ownerfor suchpackagingif the product
received by Krell ® wasboxedin non-
standardpackagingor if the original
packagingwasso damagedthat it was
unusable.If Krell®determinesthat new
packagingis required, the ownerwill be
notified beforethe productis returned.
To purchase additional packaging,
please contact your authorized Krell
®
dealer,distributor, or the Krell®Service
Departmentfor assistance.
Krell ®is not responsible for any damage
incurredin transit. KrelPwill file claimsfor
damagesas necessaryfor products dam-
agedin transit to the factory. Theowneris
responsiblefor filing claimsfor shippingdam-
agesthat occurduringthe return shipment.
Replacementparts and/or productswill be
furnished on an exchangebasis only; any
parts and/orproductsreturnedto Krell®for
exchangebecomethe property of Krell
®.
Noexpressedor implied warranty is made
for anyKrell®productdamagedby accident,
abuse,misuse,naturalor personaldisaster,
or unauthorizedmodification.
In theeventthat Krell® receivesaproductfor
warrantyservicewhichhasbeenmodifiedin
anywaywithoutKrell®authorization,all war-
ranties on that productwill be void. The
productwill bereturnedto original factory
layoutspecifications at theowner’sexpense
beforeit is repaired.All repairsrequiredafter
the product hasbeenreturned to original
factory specification will bechargedto the
customer,at currentpartsandlaborrates.
Tocontactthe Krell ServiceDe)artment
TEL [phone]
Monday-Friday
9:00 amto 5:00 PMEST
FAX [phone]
[e-mail]
KAV-150a
PRODUCT SERIALNUMBER
Toregister yourproductfor warrantybenefits,
completeandreturn the WarrantyRegistration
ICardenclosedin the shippingboxwithin 15days
of purchase.Thankyou.
KRELL
® KAV-150a English Page9 of 12

Krell®Industries,Inc.
45ConnairRoad
Orange,CT06477-3650USA
TEL[phone]FAX[phone]
E-MAIL[email protected]
WEBSITEwww.krellonline.com
KAV-150a
PowerAmplifier
Specifications
FREQUENCYRESPONSE
20 Hz-20kHz+0.0, -0.1 dB
.5 Hz-150kHz+0.0, -3.0 dB
OUTPUTPOWER,each channel driven
8 Ohms 600W(bridged)
8 Ohms 150 W
SIGNALTONOISERATIO
112dB,"A" weighted
DISTORTION
1 kHz 0.06% THD
20 kHz 0.25% THD
GAIN 25.8 dB
INPUTSENSITIVITY
1.8 Vrms
INPUT IMPENDENCE
100K Ohms
OUTPUTVOLTAGE
Peakto peak
RMS 116V
41 V
4 Ohms 300 W
POWERCONSUMPTION
Idle 40 W
Max. 600 W
DIMENSIONS
19wx 3.7hx 15.5din.
47.5wx 9.25h x 38.75dcm
WEIGHT
Shipped
Unit only
33Ibs., 14.9kg
25Ibs., 11.4 kg
All operationalfeatures,functions,specifications,and
policiesaresubjecttochangewithoutnotification.