Carver Sonic Holography HR-732 User manual

HR-732
&HR-742
SonicHolognaphf
Receivens
with
ACCD
FMTuning
Section

/I\ m /l\
/ ,l \ RrsK
oF
ELEcrRrcsHocK / | \
/ t \"'-.-riorioioi'En"--'l
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CAUTION:
TOREDUCETHERISK
OFELECTRICSHOCK
DONOTREMOVE
COVER
(OR
BACK)
NOUSER.SERVICEABLE PARTSINSIDE
REFERSERVICING
TOOUALIFIED PERSONNEL
Safety
Instructions
1.Readlnstructions - All the safetyandoperation
instructions shouldbereadbeforethe Carver
Component isoperated.
2.RetainInstructions- The safetyandoperating
instructions shouldbekeptfor future reference.
3.HeedWamings- All wamings on the Compo-
nent and in theseoperatinginstructions shouldbe
followed.
4.Follow Instructions- All operatingandother
instructions shouldbefollowed.
5.WaterandMoisture- TheComponent should
not beused nearwater-for example,nearabath-
tub, washbowl,kitchen sink,laundrytub, in awet
basement,or nearaswimming pool, etc.
6.Ventilation - TheComponent shouldbe
situatedsothat itslocation or position doesnot
interferewith itsproperventilation. Forexample,
the Component shouldnot besituatedon abed,
sofa,rug or similar surfacethat may block any
ventilation openings; or placed in abuilt-in installa-
tion suchasabookcase
or cabinetthat may impede
the flow of airthrough ventilation openings.
7.Heat-The Componentshouldbesituatedaway
from heatsourcessuchasradiators,or other devices
which produceheat.
B.
Power
Sources
- TheComponent shouldbe
connectedto apowersupplyonly of the type
described
in theseoperationinstructionsor as
markedon the Component.
9.PowerCordI'rotection - Power-supply
cords
should berouted sothat they are
not likely to be
walkedupon or pinched by itemsplaced upon or
againstthem, paying particularattention to cordsat
plugs,conveniencereceptacles,andthe point where
they exit the Component.
Thelightningflashwitharrowheadsymbol
within
anequilateraltriangle
isintendedtoalert
theusertotheoresenceofuninsulated
"dangerous
voltage"within
theproduct's
enclosure,thatmaybeofsufficient
magnitude
toconstitutea riskofelectricshockto oersons.
The
exclamationooint
within
aneouilateral
triangle
isintendedtoalerttheuserofthe
presence
ofimportant operatingandmain-
tenance
(servicing)
instructions
in
theliterature
accompanyingtheappliance.
10.Cleaning- TheComponent shouldbecleaned
only asrecommendedin this manual.
11.Non-use
Periods
-The powercordof the
Component shouldbe unpluggedfrom the ouflet
when unusedfor along period of time.
12.Objectand Uquid Entry- Care
shouldbe
takensothat objectsdo not fall into andliquids are
not spilledinto the insideof the Component.
13.DamageRequiringService
- TheComponent
shouldbeservicedonlyby qualified service
person-
nelwhen:
A.Thepower-supply cordor the plW hasbeen
damaged;or
B.Obiects havefallen, or liquid hasspilledinto
theComponen! or
C.TheComponent hasbeenexposedto rain;or
D.TheComponent doesnot appearto operate
normally or exhibitsamarkedchange
in
performance;
or
E.The Component hasbeendropped,or its
cabinetdamaged.
PORTABLECARTWARNING
Cartsandstands
-The
Componentshouldbe
usedonly with acartor
standthat isrecom-
mendedby the
manufactirrer. A
Component and
cart combination
should bemoved
with care. Quick
stops,
excessive
torce,and uneven
sunacesmay cause
the Comoonent and
cart combination to
ovefium.

Can'tWait?
If you'resuper-impatient(and/or areexpertat
stereo
theaterinstallation, you canskipahead
to
the "nitty gritty" information which ismarked
with tabson the upperright hand cornerof
manual pages.
Otherwise,
wesuggestyou read
the entire
manual carefullybefore proceeding. TheHR-732
andHR-742offerawide varietyof connection
options which you shouldconsider
in advance.
14.
SeMcing-The usershould
not attempt
to
service
the Componentbeyond thosemeans
describedin this operatingmanual. All other
servicing
shouldbereferred
to qualified service
penonnel.
15.TopreventelecLric
shock,
do not usethis
polarLed plugwith anextensioncord,receptacle
or
other ouflet unless
the bladescanbeftrlly inserted
to
preventbladeexposure.
Pour preevenirles
chocs6lectriques
nepas
utiliser
cette
fiche polarised
av€cun prolongateuq,
un prise
decourant ou une autresortiedecourant, sauf
siles
lamespeuvent €treins6r6es
i fond sanslaisser
aucune
pariiedd6couvert.
1"6.Grounding or Polarization
- Precautions
should
betakensothat the grounding or polarization
means
of the Component isnot defeated.
17.Intemal/Extemal Voltage
Selectors
- Intemal or
extemalline voltageselector
switches,if any,should
onlybe reset
andre-equipped
with aproperplug for
altemate
voltageby aqualified service
technician.
See
anAuthorized CarverDealer
for more
information.
18.
Attachment Plugsfor AltemateLine Voltage
(Dualvoltagemodelsody)- Seeyour Authorized
CarverDealer
for information on the attachment
plug for altematevoltageuse.Thispertainsto dual-
voltage
units only.
19.Power Lines - An outdoor antenna should
be located away from power lines.
WARNING
- Toreduce
the riskof fire or electric
shoc( do not expose
this appliance
to rain or
moisture.
GROUNDCLAMP
EXAMPLE
OFANTENNA
GROUNDING
ACCORDING
TONATIONAL
ELECTRICAL
CODEINSTRUCTIONS
CONTAINED
INARTICLE
810
- ''RADIO
ANDTELEVISION
EQUIPMENT''
ANTENNA
LEADINWIRE
DISCHABGE
UNIT,
roN 810-20)
GROUNDING
CONDUCTORS
(NEC
SECTTON810-21) NEC - NATIONAL ELECTRICAL
CODE.
NOTETO CATVINSTALLER
Thisreminder
is
tocall
theCATVsysteminstaller's
attention
toArticle
g2O-40
of
the.NECthat
provides
guidelines
for
proper
grounding
andinparticular,
specrtres
thatthecabte
ground
shall
beconnected
tothe
grounding
system
of
thebuilding
asclosetb
the
point
ofcableentry
aspraciical.
POWER
SERVICE
GROUNDING
ELECTRODE
SYSTEM
(NEC
ART250.PARTH)

IMPORTANT
"FAST
TRACK'
INFORMI\TION
FORTHE
IMPATIENT
USER
Whilethe
HR-732andHR-742
ore
pretty
intuitiveintheirconnectionond
operotion,thereAREimportant
Wints
which
moynot
beapparent,uen toon
expeiencedaudiophile.
These
points
(including
differences
betweenthetwo
receivermodels)
orenotedinboxeslike
thisone.Soevenifyoujust
skim
the
monuol,make
suretoreodeoch
box,
Amessage
from
Bob
Caruer
Congratulationson purchasing
atruly top
quality stereoreceiver;
adesignthat combines
overallsonicexcellence,usefulfeatures
and
exclusive
Carvertechnology.
The basics
Attheheart
oftheHR-732/HR-742is
asuperb
audio/video switcher/preamplifierwith moving
magnetphono stageand inputs for threeaudio-
only sources
plusthree
audio/video
sources
(picture
andsound).
Distortion
and
noise
areexcep-
tionallylow.
Dynarnichead-
roomis
high
enough
to handle themostaggressivelyrecorded
CDorLaserDisc.Moreover,
wethink thatvou'll
beimpressedwith theHR-732/HR-742'soverall
musicality,asubjectivequality
thatdefiesquanti-
fication. Part
ofthisderivesfromoveralldesign.
Partis
attentionto detail. For
example,by
motorizingwhat isessentially
astandard,
low-
distortionvolumecontrolpotentiometer
suchas
isusedin our ReferencePreamplifiers,
wecan
eliminatepotential
overloadproblems
andsimul-
taneously
simplifythecircuitry.
SonicHolographf
Included
in theHR-732lHR-742'spreamplifier
sectionis
aSonicHologram
Generator.Sonic
Holograph/o isanexclusive
Carver
invention
thathelps restorethetruespacialcharacteristics
ofrecordings. It canbringyoua
morerealistic
listening
experiencethroughpyschoacoustic pro-
cessingofthestereosignals.Insteadoftheflat,
between-the-loudspeakerimaging
associated
with conventional stereo,
Sonic
Holographf
generates
asonicimage
- asoundstage - that's
remarkablybelievable
andconvincing. You'll
experienceanoticeableincreasein soundstage
depth aswell aswidth. Furthermore,
it works
with anystereoinput includingCD's,tapes,
records,FM
broadcastsandVHSHi-Fivideo
soundtracks,and
does
not requireadditional
speakers.It DOES,however,require
carefulsetup
andspeaker
placement.
In other words,
toget
thefull effect,
vou'll have to takesometimeand
read
the instructions carefullyto fine tune Sonic
Holographf to your room and speakers.
..but
theresults
canbeabsolutelyastonishing.Weget
many letters
from Carver
owners
who simply

cannot live without the improvements Sonic
HolographyP
makeson their favoritemusic.
Serious
power amplifier sections
TheHR-732provides60wattsperchannel
while the HR-742's
ratedoutput is80wattsper
channel. Both power amplifier sections
uselarge
powersupplieswhich giveyour speakers
the
"muscle" to fully realize
dynamic musicalpeaks.
Even
atmoderatelistening levels,
bass
will be
tighter andmore authoritative thanksto the high
current/high voltageoutput of the poweramp
section. Both receivers
canalsohandlelow im-
pedance
dipsaslow astwo ohmswhich can
occurwith many popular speakers
(see
page
15
and 18for morecompleteexplanationsof
speakerimpedances).
Asymmetrical Charge-Coupled FM Detection
Thiscircuitry (ACCDfor short)canimprove
FMreceptionon stationswhich areplagued
with
multipath distortion and noise. It worksby
dynamically evaluatingthreeaspects
of the in-
coming FMsignal: signalstrength,modulation
levelandmultipath content. Basedon the qual-
ity of the signal,ACCDusesasmuch of the
undistorted L/Rcomponent (stereo)
component
as
possible
to regenerate
accurate
stereosound.
ACCDcan'twork miracles
on reallyterriblere-
ception,but it canmakeasignificantdifference
on manystations.
Simplicity asadesigngoal
Frankly,thereare60andBO-wattreceivers
on
the marketwith more flashinglights,buttons
and
bellsandwhistles.Someof them aresocom-
plicatedthat they seem
to takeadegreein
computerprogramming to operate.When de-
signingthe HR-732andHR-742,
weincluded
only thosefeatureswhich weknew to betruly
useful
andthat would not degradethe overall
soundof the receiver.Our design
goals
are
reflectedperfectlyin the elegant
appearance
and
sonic
excellenceof thesereceivers.
Madewhere?
CarverisAmerican-ownedandbasedin
Lymnwood,
Washington. Of the almost250
people
who work here,
mostareengagedin
building Carverhome, mobile and professional
audioproducts. Carver'sgoalisandalwayswill
beto provide audiophile-quality productsat
affordable
prices.Thus,westrive
to takeadvan-
tage
of manufacturing economies
andmethods
wherever
it ispossible
without lowering product
quality. Asaresult,weuseoutsideandoverseas
production facilitiesfor some
productsandindi-
catedthis clearlyon the packingbox. Suffice
it to
say
that the HR-732andHR-742are
greatvalues
becausewehavechosen
the mosteffectivepro-
duction sourcefor theseparticularmodels.
Aboutthis manual
In response
to Carver
customer
suggestions,
we'retrying anew style
of manual that's de-
signed
to covermorepossible
hook-upsand
betterexplain the operation of the HR-732/HR-
742. As
aresult,
this manual may seemmuch
morecomplicatedthan thosewhich comewith
somereceivers.
If you're newto hooking up ste-
reoequipment, wethink that you will appreciate
our detailedapproach. However,we'vealsopro-
vided ameans
bywhich the advanced
usercan
quickly grasp
the keypoints and differences
of
theHR-7
32IHR-7 42. Important information is
enclosedin boxeslike the oneon the previous
page.Even
if you don't read
any other part of the
manual,please
checkout eachof these
boxesbe-
foreproceeding.
Onceagain,thankyou!
There
areamind-boggling number of receiver
brandsand models
on the markettoday. Weap-
preciate
your choiceof the CarverHR-732
or
HR-742.Their cleanappearance
belies
thewealth
of features
andgreat
soundthat eachiscapable
of. I hopethat you will have
many years
of lis-
teningenjoyment.
Sincerely,
W- G"*^
BobCarver

Hook-Up
Save
the packingbox and
your sales
invoice!
lp p1i; yegesnV
for
repocking
your
HR-732/HR-742
ffitever
needs
ie:ice
(orifyou
move).
Keep
thesoles
receiptfrom
thestore
where
you
boughtyour
HR-
7
32
/
HR-742.
.. |) toestablish
the
durotion
of
your
Wanonty;
2) forpenonol
nsuronce
purposes.
..,"Y1:l_9_p:li3g the box,please
check
for any
vlslDte
srg-n
otdamage
thatdid not appear
on the
ourslcle
ot thebox. If you DOencouhter
what
appears
to be
concealed
damage,
please
consult
your Carver
Dealer
before
furt[erinpacking or
installing
theunit.
Alongwith thesteps
noted
above,
take
a
mo_
ment andfill in the following information for
convenient
reference:
Model:
tl HR-732aHR-742
Sonic
Holographf Receiver
Serial
number
. Fln_ally,
takeamoment to fill out and return
the Warranty Cardthat came
with yo"i-i*".
receiver.
Placement
The
real
no-no,s
are
listedonthefirst
page
of
thjs manual. They,re
ba
sically
I
egall
f ;o'rded
warnings
about
common sense
sIuffiike,,don,t
usg
the
HR-732/HR-742
inyour
swimminN
piol,, and
"
don'ttake
thisreceiver
intimally withtouii ioctots
presciption"etc.
Assuming
youroverall
location
is
okay,
the
HR-732lHRll+2canU"
porttio""J ,, ouit'ofu
"stack".of
com-ponents.
However,
Ua
iura "ot to
DrocK
alrflow trom thereceiver,s
toppanel
venti_
lation-
areas.
Ifyouset
another
.o-'p5"L"i ""
l9potthe
HR-732
orHR-742,
make
iure
that
its
"feet"
provide
atleast
a l/4-inch gup
U"t*""" tfr"
component
andthe HR_732|HR_742.
Connection
tips
We'reaboutto launch into the actual
nitty
gltg -._.
" I "cting-cable
frenzy
that,s
neiessary
wnen
you install
a-new
component. First,
though,consider
thefollowingtips-
I Makesure
all componentsare
OFF
before
making any connections.
I Makesure
that ,,left
ishookedto left
andright is
hooked
toright,,
ateactr
connection. Theobvioui wayto assure
!!is is.tqa;lignone
hook_up
corOpiug
color
to leftandtheother
to rieht.'
_Generally
RED
isused
to signi# RIGHT.
White,grey
orblack
thenripresents
left.
I Wheneverpossible,
keep
powercords
away
from signal
cablesiiirputs
from
CDplayer,
tape
deck,
etc.)
to prevent
hum. This
is
especially
impoitant
for
phono cables
which cirry verv
weak
signals.
While hum is
lejs
ofi problem
today
than it was
in thepast,
nbise
can
still find itswayinto your system
if a
component,spowercordbecomes
too
intimatelyinvolved
with ahookup
. cable. Carver
components,power'cords
' andconvenience
outletsardail "; ih;
right side
of the chassis
(whenviewed
from the-back).Thisallows
you to
bundle all the component powercords
andkeep
them separate
frorn signal
connections.
t Type
ofhookup
cables.
Alsocalledinter_
connects,
patch cords
or RCA
cables.
There
are
lotsof different grades
of
hookup -cables.
you canpiy as
much as
$30
per
footforsome
ofthem! Whether
ornot youhear
animprovement
in
soundquality with ,,audiophile,,
inter_
connects
is
up toyourown ears.
l-towever,
really
CHEAp
oroldconnec_
tion cables
can
sometimes
DlS_connect
themselves
inside,
causing
hum oraloss
of soundin oneor both cfiannels. ne_
foreyou send
acomponent in for
s-eM9e,
swap
hook_up
cables
tosee
if
they're
theculprit. The
otherarea
of
concernare
videosignals.These
are
far
higher
in frequency
thanaudio
anO
cin
ottenbenefit
from ahigher
qualityin_
terconnect.
Several
companies
mike
sp.cialized
audio/video cables
with two
audioandonevideoconductor. Check
'emout.
I DON'TPANIC.While there
are
more
than thirty possible
connections
on the
back.
oftheHR-732lHR _7
42,matchinx
lhgm u.p
with yourexisting
equtpmerit
is
simple^.
_Besides,
youprobably
won,t
use
all of them anywav.
Purchased
at
Date
ofpurchase

Hook-up...an
overuiew
There
arebasically
threekinds of connections
on theHR-732/HR-742
(oranyotherA/V receiver
for that matter): one-wayincoming, one-way
out-going andtwo-way.
One-way
connectionssimply route the signal
from asoundor video sourceto the correspond-
ing input on the backof theHR-732lHR-742.
TheHR-732
IHR-7
42has
one-wayincoming
connections
for:
I CD Player
I Turntable
I TV (soundand picture)
I CDV (LaserDisc
or combi playersuchas
our.MD/V-S00)
I AM & FMAntennas
I Cable
FMinput
I Main In (HR-742
only. Rarely
used,see
page
14)
One-wayOUTgoingconnectionsare:
I Video
Monitor
I Loudspeakers
I Pre
Out (HR-742
only. Rarely
used,
see
page
14)
These
areeasyconnections. We discuss
each
in detailbelow. Just
makesurethat "leftsgoto
leftsand rights goto rights."
Two-wayconnectionscangetc6nsiderably
more
complicated.Theycenter
around
the
HR-732lHR-742's
audioandvideo
tape
functions
andare referred
to astapemonitor loops.
"Loops" because
asignalfrom the HR-7321
HR-742goes
out to another
componentandthen
back
to thereceiver.
Two-wayconnectionsareasfollows:
I Tape
(lN & OUT)
I VCR(lN and OUT)
Theaudiotapeloop iswhereyou would con-
nectacassette
deck,an equalizer
or other signal
processor
suchasourDPL-33
DolbySurround
Processor.
Ifyou're
connecting
anysort
of
externalprocessor
to yourHR-732/HR-742,
take
special
careto follow our instructions, illustra-
tions andgeneral
unsolicited advicein the
sections
thatfollow.
IndMdudConnections
Instead
of areallycomplicateddrawing with
allpossible
connectionscrammedinto it, wewill
discuss
andillustrate
each
possible
hook-up
indi-
vidually, sincethat's how you'll makethem: one
atatime. Figures7and2 on thenextpage
show
the rearpanels
of the HR-732andHR-742. Figure
3isageneral
overviewof what canbeconnected
to eitherreceiver.
PHONOand CD and AUX: Basic
audio
connections
PHONO.
Thisphono circuit isdesignedfor mov-
ingmagnet
cartridges
(Gain:
35dB;
impedance:
47K
ohmsresistance
in parallel
with 150 pF
capacitance).
If you areusingalow-output mov-
ing coil cartridge,you will needastep-up
device
suchasthe Carver
MCt.
If your turntable hasaground wire, makesure
to secureit to theHR-732IHR-742
groundpost
just
to theleftofthe PHONOinput sockets.
NOTE:Do not plug line levelinputs suchas
from CDplayers,
tapedecks,VCR's,
etc.to this
input. Severe
overloadinganddistortion result.
Receiver
CD PLAYER.
Just
grab
ahook up cable
and
connect.
What if you havetwo CD players?
Orthree
CDplayers
andanelectricglockenspeil
you want
to hook up? TheHR-732and.HR-742
reallyhave
four interchangable
line levelaudioinputs not
Make
sureto connect
turntable
oroundwire
Receiver

Hook-Up
Save
the packingbox and
your sales
invoke!
The
box
isnecessary
forrepocking
your
HR-732/HR-742
ffiteverneeds
service
(orifyou
move).
Keep
thesoles
receipt
from
the
store
whereyou
boughtyou
rHR-
732
/
HR-742.
.. I) toestoblish
the
durotbn
of
your
Wananty;
2) forpersonal
tnsuronce
putwses.
Ugon opening the box, please
checkfor any
visiblesignof damage
that did not appear
on the
outsideof the box. If you DO encouhlerwhat
appears
to beconcealed
damage,
please
consult
your Carver
Dealer
before
further unpacking or
installing
theunit.
Along with the steps
noted above,
takeamo-
ment andfill in the following information for
convenient reference:
Model:I HR-732
aHR-742
Sonic
Holographf Receiver
Serial
number
Purchased
at
Date
of purchase
Connection
tips
We'reaboutto launch into the actualnitty
gritty connecting-cable
frenzy
that,snecessary
whenyou install
anewcomponent. First,
though, consider
the following tips.
I Makesure
all componentsare
OFF
before
making any connections.
I Makesure
that "left ishookedto left
andright ishookedto right,, ateach
connection. Theobviouswayto assure
thisis
to assign
onehook-up
cordplug
colorto left andthe other to right.
Generally
RED
isused
to signify RIGHT.
White, greyor blackthen represents
left.
IWhenever
possible,
keeppower
cords
away
from signal
cables
(inputs from
CD player,tapedeck,
etc.)
to prevent
hum. Thisisespecially
impoitant for
phono cables
which carryveryweak
signals.
Whilehum isleis
ofi problem
todaythan it was
in the past,
noise
can
still find itswayinto your system
if a
component's powercordbecomes
too
intimately involved with ahook up
cable. Carver
components'powercords
andconvenience
outletsare
allon the
right side
of the chassis (whenviewed
from the back). Thisallows
you to
bundleallthecomponent
power
cords
andkeep
them separate
from signal
connections.
Type
ofhookup
cables.
Alsocalled
inter-
connects,
patch
cords
orRCA
cables.
There
arelotsof different grades
of
hookup cables.
Youcanpayasmuch as
$30
per
footforsome
ofthem! Whether
or not you hear
animprovement in
sound
qualitywith "audiophile"
inter-
connects
isup to your own ears.
However,
reallyCHEAP
or old connec-
tion cables
can
sometimes
DlS-connect
themselves
inside,
causing
hum oraloss
of sound
in one
orboth channels.
Be-
foreyou send
acomponent in for
service,
swap
hook-up cables
to see
if
they'rethe culprit. Theother area
of
concernarevideo signals.These
arefar
higher in frequencythan audioandcan
oftenbenefit from ahigher quality in-
terconnect. Several
companies
make
specialized
audio/video cables
with two
audio
and
one
video
conductor.Check
'emout.
DON'TPANIC.While there
aremore
thanthirty possible
connections
on the
back
of the HR-732/HR
-7
42, matching
themup with your existing
equipment
is
simple.Besides,
youprobably
won,t
use
all of them anyway.
T
Finally,takeamoment to fill out and return
the Warranty Cardth'at
camewith your Carver
receiver.
Placement
Thereal
no-no's
arelisted
onthefirstpage
of
thismanual. They're
basically
legally
worded
warnings
about
common sense
stufflike,,don,t
usethe
HR-732/HR-742
inyour
swimming
pool,,and
"
don'ttake
thisreceiver
intemally
withou{
adoctor,s
prescription"
etc.
Assuming
your overalllocation isokay,the
HR-732/HR-742canbe
positioned
as
pait ofa
"stack"
of components.
However,
be
sure
not to
blockair flow from the receiver's
top panelventi-
lationareas.
If you set
another
component
on
top of the HR-732
or HR-742,
makesure
that its
"feet"provide
atleast
a1/4-inch
gap
between
the
component
andtheHR-7321HR-742. t

I
mincluding the audiotapeloop (By
line levelwe
mean
any
signal
inputthat,s
NOT
from
a
micro_
pnone
ora
turntable).
The
otherlinelevel
audio
inputsare
labeled
TV,VCRand CDV. If you only haveonevideo
soundinput, the other two canbeused
for other
audio
components.
^_Naturally,
it'smost
convenient
to plugyour
CDplay_er
into theCDinput; stillif ybu i<ln,tyet
have
aCDplayer
but DOhave
othei,ou.ra
sources/
feelfree
to connectthem. We,ve
en_
c9ur1t91ed
tape
buffswith four or fiv-e
decks,
some
otwhich are
only forplayback,
people
who have
anextra
tuner,
orboth single
play
andcarousel
CDplayers,
etc. In these
cises,
simply
use
the
four linelevel
inputsasyou see
fit. ;tist remem_
Der
wnat you'veconnected
where,since
the front
panel
labels
andremote
controlinput buttons
maynot matchyourconnections.
Fig.l
-HR-732
FMandAMantennas
75-ohm
FMAntennaTerminal.you may attacl
a75-ohm antennadirectly,or use
the sm'all
:OO.
ohm dipole FMantennaand adaptors,rppileO
with theHR-732iHR-742.
If youifV caUte
Uox
ha;.a
snegigl
FMoutput,
youmay.orr.r".idi_
rectly
to it instead
of to anexternal
antenna
(consultyour localcable
operatorfor detaili).
CAUflON: EXTERNI|I
ANTENITU\Ii
CAtrt
ZApyOU!
Extreme
core
must
beused
when
conneding
your
receiver
toan
external
outside
TV/FM
ontenna.
See
theNotice
otthe
front
ofthis
monuol.
lfyou,re
not
100o/o
sure
ofthe
procedure,
consult
qua
lified
insto
llatbn
person
nel.
PHONO
&
GBOUND
Fig.2-HR-742
AUDIO
CONNECTIONS REI\4OTE
CONNECTIONS
VIDEO
CONNECTIONS
PRVI\,4AIN
CONNECTIONS
I
VIDEO CONNECTIONS
SPEAKER
OUTPUTS
AM/FM
INPUTS
PHONO
&GROUND
SPEAKER
OUTPUTS
REI\,4OTE
EXPANSION
FOR
FUTURE
USE
AI\,4/FM
INPUTS
o 6 ' o o 6'e-elJ16ro
,1,,R'9Pgpgpgl.F SMEA
MP€MT
SYStrSAS33
M]NMUM
SYSEMANDO6MtrMUil
AUDIO
CONNECTIONS

Fig.3 Turntable
(w/MMcartridge)
Cassette
Deck
l
VCR
1
, ,
Surround
Sound
processor
(wnrcn
does.
not have
amaster
volume
control.
Kear
channel
amplifier
and
speaker
connections
notshown)
o
0u";po1 l--r_
| | yooo@
0 trtrtrtrEffi
ol
ll i-l '*rl
U trtrtrtrtrtr
U
t+l++ttt+l
t+l++ttt+l
trtrtr
C{R\m.""rc Horos,aphy
A/v
aeceive,
HR-742
9_ 9 _99 o ".,@.
".,q .:@,
PNoNES sptrE's ffi H.L*FAM *;*
TB.BLE
* " -"8 -**E nsLA , ry cov vcq ,.\.or D,o LF,o r
ITI
w;T:4 ll r-r,-rr.
".€.:
" I : **,i_titij,5j_:i
i:i,yl]s'_ ffi
o
o
o
o
Second
Set
of
Smaller
Bookshelf
Speakers

"T"
Dipole
AMLoop HR-732 Receiver
AMAntennahook-up.
The
AM loopantenna
providedwill provide goodAM receptionin most
areas.Position
theantenna
forbest
sound. It
mayalso
bewall-mounted
with thesupplied
bracket.
$-v_vord
(actually
lots
ofwords)
about
FM
antennas
We suggestyou startwith the dipole included
with yourreceiver.
It's
designed
toworkwellin
many different places
and situationsandwill get
you started
enjoying FMright away,
before
set-
tling on another
antenna
system
orcommercial
cable.Professional
installers
we've
talked
to ob-
serve
that atleast
75o/o
of allreceivers
havea
dipole
attached
andtheowner's
are
quitesatis-
fied.
However,
under
certain
circumstances,
vou
mayneed
adifferent
kind of antenna.Because
even
thefinest
receiver
tuning section
can,t
do
much if it doesn't
get
astrong,
clean
signal.
If
you liveclose
to acityin asuburban
area,
chances
are
good
you canskip
thispart. But
if
you're
in arural
area,
theheart
ofa
citywhere
you're surrounded
by tall, steel-frame
buildings,
or want to receive
extremelydistant stations,
a
simple
FMdipole
antenna
llt<e
theoneprovided
with yourHR-732/HR-742might
not be
suffi-
cient,
even
with themagic
ofACCD.
In general,
the higher your antennais,thebet-
terit will perform, sinceradiowaves
travelin a
straightline. A properly positioneddirectional
antenna
minimizes
background
hiss
andis
less
likely to pick up multipath distortion andnoise
from carignitions. Conversely,
anon-directional
dipole
isn'tvery
directional
andcannot
beeasily
repositioned
Onepossibility
is
a
powered
indoorantenna.
Somenewdesigns
havegainboostingcircuitry
andadjustable
directivity, housed
in anattraclive
package.
Checkwith your dealer.
When mounted andconnected
properly,adi-
rectionaloutdoor FMantennacanprovidethe
best
signal
of all,with thelowest
interference
and
noisefactor. Butyou have
to do it right (see
the
warnings
andinformation atthebeginning
of
thismanual). Indeed,
theonly disadvantage
to
outdoorFMantennas
is
thecostoftheantenna,
mounting hardware,
andarotator if you want to
point these
highly directional
antennas
atsta-
tionsthatmaybein opposite
directions.
But
whenproperly
installed,
anoutdoor
antenna
can,in most
areaspull in anincredible
number
of
stations
fortheHR-732lHR-742's
ACCDproces-
sor
to clean
up. Which antennatypeisbestfor
you depends
onyourFMlistening
habits
and,
of
course,your location. Consultwith your Carver
dealerfor
more
antenna
information.
Feedlines
arealso
animportantpart
ofgetting
good
FMreception
from anoutdoor
antenna.If
the link from your antennato your HR-7321
HR-742
ispoor,you'll cancel
anyadvantage
from
its
height
orsignalgain.
There
aretwo basic
types
of feedlines.300-
ohm twinlead
is
inexpensive,
and
if conditions
arerightandit isproperly
installed,
signal
losses
arereasonable.
However,
if thetwinlead
isn'tin-
stalled
right,it can
actasits
own antenna,
degrading
the performance
of the HR-7321
HR-742
by picking up extraunwanted signals
andinterference
noise. Twinleadrequires
careful
routing
and
must
beinsulated
withspecial
"stand-offs"
from everything
made
ofmetal,
like
gutters,
other wires,
etc. Compared
to average
twinlead,
75-ohm
coaxial
cableis
more
expensive
andabit harderfor signals
to getthrough, but
hasreal
advantages,
too. It won't pickup extra
noise
andinterference
because
it'sshielded.
Also,
you don't haveto beascareful
aboutrouting, so
installing
75-ohm
is
much easier.

CATVinput
Thislabelispotentially confusing,sinceit's re-
ally justanother FMantennainput intended for
connection to cable
boxesthat haveFMoutputs.
cAw INPUT
FORFM
ONrY
NOTVIDEO
DONOT
usethisinput
asa VCR
connectbn.Connectinq
the
video
portbn
of
yourVCRtoihe
HR-.32/HR-
742
shouldbemode
usingRCAtype
cords
ondthecompositevideo
inputs
ma*edVCRVIDEO
lN.
TV & CDV (IN): One-way audio/video
connections
(Ifyou loatheTV or only haveaS-inchsetin
your sparebathroom, you canskipthis section
andgo
directly
to page 14. Otherwise...)
The
HR-732lHR-742
enables
youto connect
and selectfrom multiple video sourcesincluding
combi Laser players
and stereoTV's,with or
without videooutputs.
A "video source"isdefinedas
ofie having com-
posite
video
cable
plus
leftandright stereoaudio
cables.
Thusboth the TV and CDV video inputs
have
THREE
socketseach,
two for audio towards
the left hand sideof the backpanel,and and one
for compositevideotowardsthe right side.
What'scomposite?
A "composite" videoout-
put will havean RCAphono-type socket
(likethe
onesusedfor audioconnectionsbut with adiffer-
ent-coloredplastic
center),
rather
than a75-ohm
coaxconnection which sticksout andhasscrew
threadson it. All VCR,
CDV,"combi" and
LaserDisc
players
havecompositevideo outputs.
VCR:Two-way audio/video connection
Note that your receiver's
VCRconnectionsin-
cludeboth audio IN & OUT andvideo IN & OUT.
Thisallows you to recordfrom another videoin-
put routedthrough the receiver
to your VCR. It
also
enablesyou to useaVHS
Hi-FiVCR
asahigh
quality audiorecordingdevice.
Considering your audio/video options
First, you shouldhaveaclearideawhat it is
you want to dowith theHR-732lHR-742's
video
features.
.We
included
video
connections
fortwo maior
reasons.First,
soyou canhaveHomeVideo
Theater
soundwhen you watch VCR
movies.
Second,
so
you caneasilyswitchvideo sources
us-
ingtheHR-732iHR-742's
remote
andalsocopy
between
two video sources,for example,
aVCR
andaLaserDisc,
ortwo VCR's.
What follows areaseries
of connectionswhich
giveyou different audio/video options. We often
getcalls
from newCarverowners
who ask
"Well,
which isreallyRIGHT?". That completely de-
pends
on what kind of video equipment you own
andjusthow closelyyou intend to integrate
things. Lookthrough the hook upsonceandsee
which pertainto you.
A/V hook-up 1:R* for better movie sound
Canbeusedif you have:
t AVCRor other stereovideo source
I Anon-stereo
TVthat lacks
composite
videoinputs
Byrouting video soundtracks
through your
main speakers
(oranother sethookedto the
HR-732/HR-742's
Bspeaker
outputs),you can
dramaticallyenhance
the sonicimpact of video-
cassette
or LaserDisc moviesandconcerts.
Although this wasn't alwaysthe case,video
soundfrom current model VHS
Hi-FiVCR's
is
now as goodor betterthan most audio sources.
Virfually all newermovie releases
on tapeare
VHS
Hi-Fistereowhich has
excellent
dynamic
range,wide frequencyresponse
andlow noise...
And if you own aLaserDisc
player
with digital
soundtrack
capabilities,you haveagreat
oppor-
tunity to createahome video theater.
In anyofthese
cases,
you're
simplytreating
thevideo soundsourcelike another HR-732.
HR-742
stereo
audioinput.
Television/Monitor
(back
view)
75
VI-IFOUT
I
i iir NVCR
HR-742
Receiver

NOTE:
If yourvideo
sound
source
is
mono
(y_ou'll
see
just
one
socket
most
likely
labeled
AUDIOOUT),
add
a,,y-splitter,,,
aviilable
from
many audio
dealers
orradio
supply
stores.
R/V hookup 2:.Switchingand copying
betwe€n two video sources
Should
be
used
ifyou have:
I TwoVCR's
orone
VCR
andaLaserDisc
Player
I Anon-stereo
TV
Jfyou havetwo VCR,s
or other combination of
video
playback
gear,
connect
themas
shown
be_
Iow. NotethattheVCR
connected
to VCR
will be
thetargetdeck
for recordingandthe oneplugged
into TVor CDVwill be
thesource.
I Astereo
TVwith audio/video
outDuts
This
is
avariation
ofthelast
hookub. We
in_
clude
it because
even
really
killer
direci_view
and
big-screen
TV'shavespeakers
that are
rarelyup to
parwith your main stereo
speaker
system.An^d
there's
no reason
why youriavorite'sitcom or
soap
can't also
benefitirom ,,big,,
so,rna
tt rough
your loudspeakers.
Besides,
moie andmorepro_
grams
are
beingbroadcast
in MTS
stereo,
which
hasprettydecent
audio
specifications
_ atleast
no worse
than those
ofmost
prerecorded
cassettes.
- If you haveastereo
TVor remotecontrol cable
box
with audio
OUTputs,
you
can
treat,.21m
Droadcast
television
as
an
audio/video
inp-ut
and
switch
it through
the
HR_732iHR_742.
Thet.V
or
cable
box"tunes"thestation,
sends
thesound
to
thereceiver
andthen toyourmain,better_sound_
ing
stereo
loudspeakers.
_-]I yg" have
a
-"stereo-ready,,
TVbut anolder
VCR
that lacks
anMTSstereo
tuner,this connec_
tion has
another
benefit:you can
record
onto
theVCR
using
yourTVas
thesource.
VCR1CDV
(Source
for Dubbing)
OUT IN
Adb Vda Audb Vd@
a€:'l.r8:
Jt il-- +
-1
Itlllt
oll
oll
o @ll
e
kk p,'
Receiver
Q
I
Television/Monitor
(backview)
A/V hookup 3:Bettersound from TV
progmms
Can
be
used
if youhave:
One
VCR
orother
video
source
Television/Monitor
(back
view)

A/V hookup 4:Takingthis wholethingone
stepfarther
Canbeusedif you have:
I OneVCRor other video source
I A stereo TVwith audio INputs
Thishookup allowsyou to takeadvantageof
the speakersin the TV as well as your largermain
stereospeakers.Assuming
you only haveone
VCR,it will provideyou with evenbettermovie
sound,sincethe TV speakers providedialog
centering.
Television/Monitor
(back
view)
A/V hookup 5:Using aVHSHi-Fi VCRasa
recorder.
VHSHi-Fiiscapableof extremelyhigh quality
AUDIOrecording.
Youcan
get
theequivalentof
fourC-90cassettes worth ofmusicon asingle
T-72Ovideotape
- andwith specificationsthat
rival professional
tapemachines: TypicalVHS
Hi-Fi
specsare20Hz-2OkHz+0.1dB,90dBdy-
namicrange
and90dBsignal-to-noise.
Just
make
sureto useapremium videocassettetapetype,
don't record on the first two minutes of the tape
wheredrop-outsare mostprevalentandNEVER
lettheVCR'saudiolevelmeters
exceed0.
Thefollowing hookup may not beoneyou'll
wantto makepermanent,
but sincetransferof
records
to VHSHi-Fiisoften aone-time
"archiving" process,
reconnectionisworth the
troublefor anoccasionalsession.
TAPEMONITOR: A two-way audio loop
connection
Asweexplainedearlier,
tapehook upsaretwo-
wayconnections.A signalto betaped goes
out of
theHR-732/HR-742
to thecassettedeck;asignal
returns
to theHR-732/HR-742whenyoupress
the deck's
PLAY
button. As
you'll soonsee,this
loop canbeget itsown loopsfor signal processing
equipment,too.
Here'stheconnectionforacassettedeck.
CassetteDeck
&3:;b
*m3ffi.
Receiver
IFYOU
HAVETWO
CASSETTEDECKS
butnoVCR,
you
canusetheVCRoudio
inputs
ondoutputsososecondtape
monitorloop.
Adding sound enhancement components
There
areallsortsof "black
boxes"
which you
canaddto your system.Theseinclude equalizers,
dlmamic
expanders,
noise
reductionunitsand
multi-function units suchassurroundsound
decoders
andspecialequalizationboxeswhich
arerequired with somespeakersystems.
Any time the HR-7
32IHR-7
42'sTAPE
MONI-
TOR
button ispressed, the soundfrom any signal
c'@@s
cw#p
irir ,r ai:
Receiver
sSH.=@Ag@
*r"'GR v(F MoNl

_source
will beaffected
by the signal
processor.
Yetyou canstill recordd"a pfui Ui.i -i-tf, tn"
cassette
deck.
ThePRE-MAINloop (HR_742
only)
Your
receiver
is
really
three
compbnents
in
::_"',f,lll"r, a
preamplifier
and
upore, ampli_
ner. we've
provided
awayto sepaiate
the
ff::11l gq_pow:r
amp
sections-.
Traditionally,
rnls
nas
been
used
to ,,upgrade,,
asystem,s
power
outputby adding
ala_rger,
separate
power
ampli_
fier
such
as
our
rpv-25
"i rt'v_+s-.
ii;;;;"
Hl::l[119ry1wiilr,
the
HR742,stu"6,
*o pr._
ampttller
tunctions,
but
want
mega_power,
this
is
a
super
way
tofurther
enhance
yduriystem,
now
or
at
alater
date.
Remember
ttritttre
irne
--
OUTputs
are
affected
bytheUR_Z+Z;,
"oLm"
control.
Receiver
. Th9hookup above
turns the HR_742into
a
tuner/preamplifier
anddoesn,t
use
thereceiver,s
amplifier section
atall. Howe"e., if vo, uai u
Dolby SurroundSound
unit that do6sn;t
tiive its
own built-in amplifier,
youcan
make
use
of the
raK-
/+z'
,s
amp
to drive
two ofthefoursurround
sound
channels.
Speakerconnections
YourCarver
HR-232/HR
_742hastwo
sets
of
speaker
outputs
on its
back
panel. yo, _av.on_
,1::,t
tyg,puirs
of
speakers*
and
play
eirher
or
Dotn
ot them atthesame
timeusing
theSpEAK_
ERS
A& SPEAKERS
B
buttons
on th;fr;;i panet.
Use
thickwireforspeaker
connections.
your
Carver
dealer
can
recommend
abrand
ofhigh
quality,
oxygen-free
speaker
caUte.
Oicorr-o.
zrpcord" trom ahardware
store
canbeem_
ployedif care
istakento use
aheavy"rrougl,
$3lg_"^^I!1 will dependon the disiance
frtm the
HR-732/HR
-7
42toyourspeakers.
Ure
lt efolo*_
ingchart
as
a
guidei
WIRE
LENGTH GAUGE
OF
ZIP
CORD
J]n
toqrt l8 gauge
Up
to20
ft l6 fauge
Up
to50
ft l4 gauge
,""Y]:.^,H:f
qess
sRecification
s
or,,gauges,,
get
rarger
as
the
wire
gets
thinner:
Thus16_!auge
wire
is
thicker
than
22_gaug"
*ir"- ih. ii"l,.,
the
distance
berween
y5.,rftn_z:i Er*Tii u"a
speakers,
the
larger
the
diameter
the
wire
shoutd
be.
Use
thesame-length
of speaker
wire
forboth
speaKers/
even
if one
is
closer
to thereceiver
than
theother. Coil uptheexcess
andmake
sure
it,s
wel away
from theHR_732/HR_742turntable
inputs.
Polarity.
It is
important to make
sure
thatboth speakers
connected
to theAorBterminals
are
hook?d
up
thesame
way:
7 tt-"attheHR-23
2lHR-Tl}speaker
out_
puts
to "-,,on thespeaker
bick, and,,+,,
attheHR-732lHR_742
speaker
outputs
^ to
"+"
on
the
speaker
back...and...
'
z) Left
HR-732lHR-742
speaker
outputs
to
leftsp.eaker
inputs,
anilright HRi3ti-
r-rn-
/+zspeaker
outputs
to right speaker
inputs.
*See
Poge
1
8
*Speaker
im@ances
While
the
HR-732/HR-742
is
copobte
of
high.cunent
output
into
momentory
low-impedances,
we
do
not
recommend
ploying
twosets
of
4_ohm
speakes
simultoneously
othiah
volumes
(see
"Afufthei
notedbout
impedonces"
forther
on
in this
section).
O.fcourye,
you
con
certointy
hook
up
wo,p"iry
?f
1.ohm
speaken
ondpiay
eoch
poir
indMdually.
tfyou,re
not
sure
otthe
Roted
Nominal
lmpedonce
of
your
speoken,
consult
the
owner,s
monual
which
comewith
the
speokers,
or
call
the
manufacturer
oryoir deoler.
Wire.

If you're usingspecial
speakerinterconnects,
"
+" and"-" will beidentified. If you're using
plain appliance-type
zip cord,the two conductors
will bedifferentiatedin oneof severalways. They
maybedifferent colors(silver
vs.copper). One
may havefine grooves
on itsoutside. Or one
may haveapiece"of
yarn included in oneof the
conductors(visible
afteryou strip off the insula-
tion). It doesn'tmatter which oneyou decideto
call" +" or "
-" ,justbeconsistanton both speak-
ers.
Speakerhookup
The
HR-742
speaker
terminals
aredesigned
to
accept
bare
wire, spadelugsor banana
plugs. The
HR-732's
speakerterminals areintended only for
barewire.
1. Ifyou're
using
barewire,
strip712"of
insulation from eachwire and make
sureto carefullytwist all the fine strands
together. If evenoneisloose
andcan
touch the oppositeterminal, ashort
circuit may result.
2. UnscreweachHR-742
speaker
terminal
andinsertthe wire asshownuntil the
insulation
igcloseto theholeOR
press
thereleaselever
on theHR-732
speaker
terminal andinsertthe wire into the
centerhole,making surethat the wire's
insulation doesnot preventelectrical
contactwith itsconductior.
Tighten theHR-742connection or re-
lease
the HR-732
speaker
terminal lever.
Afteryou've hookedup oneor two sets
of speakers,
double-checkyour
connections.
3.
4.

Speaker
System
A
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HR-732
Receiver
Speaker
SystemB

Convenience
outlets
Wecovertheselastbecause
wedon,t want to
encourage
yoy to plug anything in or turn any-
thing on until all other connectionshavebeen
made.
. Thereare
two ACoutletson the backof vour
Carver
HR-732/HR-742.
The
onemarked '
SWITCHED
provides
poweronly when the
HR-732/HR-742is
turnedon andis
useful
for
componentswhich you useevery
time you play
your system
suchas
anequalizer,
aspeaker
equal-
ization box, etc.oryour most-used
soundsource
- aCD player,for example.
HR-732/HR-742spitched
outlet warning
Donotplug
opower
amplifier
intothe
HR-7
32
/HR-
742's
switched
outlet.
Make
sure
thottotal
power
consumptbn
of
anyother
components
plugged
intothis
outlet
doesnotexceed
|00wotts.
An UNSWITCHED
ACoutlet isalsoprovided.
It'salways
liveaslongastheHR-732lip,-Z+Zis
pluggedinto the wall. Adevice
connected
here
may beleft permanently on, or maybeswitched
off with itsown switch. NOTE: In orderto avoid
potential turn-on thumps, anything plugged
in
here
should
be
powered
up BEFORE
theHR-732l
HR-742
isturnedon.
The
fi
nal obvious
connection
Youguessed
it. Aftermaking sure
that the HR-
732lHR-742
isoff, plug itspowercordinto a
properly polarized
wall receptacle(see
Safety
In-
structions
77
and
18atthebeginningof
this
manual).The
HR-732lHR-742
maybeconnected
to anextensioncordor multiple outlet plug,pro-
vided they havethe properpolarization (one
wider andonenarrowerprong). If you are
using
anextensioncord,werecommend 16gauge
or
heavier.
*A
furthernoteabut speaker
impedances
(extra
infoimation
for
thosewhohdve
multiple
speaker
qystemt
like
to play
loird
music
with
lots
ofbass
init'orjust like
to read
owne/smanuals)
Why dowepublish specifications
for ,,2-ohm
dynamic power" andthen warn you aboutnot
usingtwo sets
of 4-ohm speakers
atthe same
time? Because
impedance
has
several
variables
andbecomes
afactoratdifferent times.
Speakers
arenot simply resistive
loads. Instead
they are
complex and reactive,
drawingdispro-
portionately large
currents
in reactionto
transientvoltagesignals.Because
musicisdy-
namic,with multiple instantaneous
peak
power
demands,
the speaker
isconstantly bbmbarded
with shorttransientvoltage
drivesignals
and
constantlydrawing short "in-rush" currents.The
overalllong-termvoltage
andpowerdraws
arenot
significantly higher than thoseof aresistive
load.
Butatanygiven moment, shortterrnpeak
cur-
rentsmustbedelivered
farin excess
of the
average,demands.
If these
cannot besupplied
by
anamplifier, distortion and reduced
dynamic
range
result. Impedance
isacomplexproduct of
factors
such
asresistance,
inductive reactance
andcapacitive
reactance.
Realistically,
it,sa
rating of how the speaker
will behavewhen con-
nectedto anamplifier and playing music. The
lowerthe impedance,
the moreamplifier current
will berequired.
Modern speaker
systems
mostoften have
NOMINALimpedance
ratings
of4,6,
or8ohms.
Thisrating canbefound in your speaker
hand-
book,isoften printed on the backof the
loudspeaker
andcanalso
befound in Audio
Magazine's
AnnualEquipment
Directory.
The
HR-732lHR-742
is
designed
for
CONTINUOUS
usewith 4-ohm or 8-ohm speaker
impedances.
If you'rejust
using
onesetof ipeak-
ers,
there's
no problem - virtually anything you
connect
to theHR-732/HR-742willhave
anomi_
HR-732/HR-742
unsryitched
outlet warning
lfyou're
using
oseporote
power
amplifierto
drive
sunound
sound
speakers,
asubwnfer
orinconjunctbn
with
theHR-732/HR-742's
PRE
OUT
connectbn,
takecare
whenplugging
stuffintotheHR-7
3
2
/H
R-742's
tJ
N-
switched
outlet.Thepower
ratingfor
this
outletis1
00wotts.Consult
the
power
amplifier's
owners
monuol
to
determine
its
overall
power
consumption
ifindoubt.

SpeakerPair
ASpeaker
Pair
BGombined
lmpedance 0Kor not
0K
nalimpedance
of4,6,or8ohms. Butif you're
connectingTWO setsof speakers,
the impedance
ofboth setsbecomesimportant - and
interactive.
Total impedance(Z)of suchasystemiscalcu-
latedwith the following formula:
7-=Z.XZ,
Zr+
Z,
WhereZ, andZ, aretheindividual impedances
of the two speaker-rystems.That leads
to the
following chart:
Simultaneous
speakeropelation
And yet itspublished "NominalImpedance"is6
ohms! Obviously, 6ohms isanoptimistic
average,NOT aqonstant.
Note also
that this popular,widely-distributed
speaker
takesitsmost seriousimpedanceplunge
in the lowestfrequencieswherethe mostpower
isrequiredfrom areceiver's
amplifier section.
This
design's
perilous
50Hzand100Hzdips
correspondwith many musicalinstruments
including kick drums,floor tom drums,tympani,
pluckeddoublebassviols andelectricbass
gui-
tars. Youcanimagine how anamplifier istaxed
on awell-recorded
CD atrealisticlistening levels
with this speaker.
In addition, becausemusichas
awide and
constantlyvarying frequencydistribution (and
listeners
havewildly different viewson whereto
setbassandloudness
controls),
problems
stem-
ming from intermittantly low speaker
impedances
cancropup unexpectedly.
Whether anything unpleasanthappens
when
aspeaker'simpedance
dipsinto the2-ohmrange
during asongdepends
on the amplifier design
-
particularly itsability to producelarge
amounts
of currentfor shortperiods
of time into low im-
pedances.
Wehave
designedtheHR-732
and
HR-742
to satisfysuchmomentary powerde-
mandsandthe receivers'
"2-ohm dynamic
power" rating reflects
this ability. Still,it doesn't
meanyou shouldoperatethe receiverinto acon-
stant2-ohmload.
Following ashort section
on the HR-7321
HR-742'sremotecontrol andaguidedtour of the
receiver's
front panelfeatures,you'll beready
to
startenjoying your new component.
8
6
o
A
4
8
8
o
8
i
4
3.4
J
2.7
2
OK
Maybe0K-
Maybe0K.
NO
NO
.lf
you
don't
play
the
speakersystemstooloudly
at
the
same
time
Asyou cansee,two sets
of B-ohmspeakersin
parallel
represents
a4-ohm total load,well within
the operatingparameters
of your HR-7321
HR-742.However,
two sets
of 4-ohm speakersisa
2-ohm loadand isnot recommended. All of this
ispredicated
on operatingboth setsof speakers
ATONCE. If you neverintend to operatetlvo
pairatthe sametime, both paircanbe4 ohms
nominal impedance.
Now what about "2-ohm dynamic power"?
First,it's important to understandthat
NOMINAL isafancyway of saying
"sortof".
While aspeakerisnominally ratedat asingleim-
pedance,
it usuallyvarieswidely overthe entire
frequenry range. Shownbelow isapopular
3-wayloudspeaker's
trueimpedance
curve. Note
that it varies almost 10
ohms acrossthe 20Hzto
20,000Hzmusicalspectrum.
8ohnrs
4ohnrr
2ohnrs
l
fi
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