Shure HTS50SPA User manual

HTSSOSPA
Power Amplifier

HTSSOSPA SIGNALPROCESSING STEREO POWER AMPLIFIER
INTRODUCTION
Congratulations!You have chosen the Shure
HTSSOSPA Signal Processing Stereo Power
Amplitier,speciallymade as an integralpart of
your Shure HTS Theater Reference System.The
other elementsof the Shure HTS Reference
system are the HTS5300Am-Vector
' wc
Decoder,HTSSOCF Center Front Loudspeaker,
HTSSOLRS Front and Surround Loudspeakers,
and HTSSOW SubwooferLoudspeaker.These
products of Shure'sHome Theater Sound
Division re-createin your home the same
realism and
immediacy you hear in the very best
motion picture theatersand production dubbing
stages.
The ShureHTS5300Am-Vector Decoder is
the
main control centerfor your Home Theater
System; the HTS5300employsthe latest
exclusiveShure-patentedtechniquesin
analog
and digitalsignalprocessingelectronics.
See the System Manual included with your
HTS Decoder for complete system installation,
connectionand operation information.
Theory of Operation
The HTSSOSPA amplifierprecisely matches
both the Shure HTS Decoder and ShureHTS
Loudspeakers.The output response of the
'U.S. Patent 4,696,036
HTSSOSPA is tailored to correspondto theparti-
cular Shure HTS loudspeakersystem selectedin
each of its HTSspeaker-correlatedswitch-
selectableOperationalModes. Through
extensivelaboratorytesting and many hoursof
program listeningthe ShureHTS Divisionhas
achieved
an optimum correlationbetween the
program materialand sound delivered to the
room.
As theprogram signal is traced through
the HTSSOSPA tothe output connectors,it
is
correctedfor the loudspeakernossover
interaction,loudspeaker-to-roomtransfer
functionand program-materialdependence
whether theprwm
is cinema or conventional
music audio.Multiple circuitfunctionscombine
to control thepr-ration of an accurate
soundfieldat the listenerpositionsin aroom.
Such attentionto detail
is present in onlythe
Enest audiosystems,and the Shure HTS Theater
ReferenceSystem setsthe new standard.
Consequently,the HTSSOSPA offers the user
an amplifier that
is outstandingfor highest
qualityhome theater audio-videopresentations
as well as one that providesunique signal
control in conventionalmulti-channelaudioonly
listening.
The
LRSx and CFxextended low-frequency
Operational Modes are intendedfor use
respectivelywith the HTSSOLRS and HTSSOCF
Loudspeakerswhen the HTS system
does not
includea subwoofer. In these two Modes,
amplifier low-frequencyoutput
is extended to
help compensatefor the lack of a subwoofer.
The LRS and CF modes are
also intended for
use with the HTSSOLRS and HTSSOCF loud-
speakers,but in a system that
does include the
HTSSOW Subwoofer.In these two Modes,
amplifier lowfrequencyoutputcutsoff at 80
Hz
to complement thefrequencyrange of the
HTSSOW Subwoofer.
When Channel
1 is in OperationalMode
SW, amplifier output extendsfrom 33 to 80 Hz
to match thefrequencyresponse of the
HTSSOW Subwoofer.
To further enhanceitsversatility, each
channel of the HTSSOSPA amplifier
also includes
a "Flat" output mode,
makmg it suitablefor use
with any loudspeaker.
An excursion lunitingcircuit in the
HTSSOSPA continuouslymonitorsthe audio
signal.
This circuitrymodifies the low-frequency
response only when necessary toprevent
overexcursion of the loudspeakerconnectedto
that channel.The characteristicsof
this circuiy
depend on the OperationalMode selected since
each Mode is correlatedto the HTS Loudspeaker

RISK OF ELECTRIC SHOCK
AmA
CAUTION.
TO REOUCE THE RISK OF ELECTRIC SHOCK
DO NOT REMOVE COVER
NO USER SERVICEABLE PARTS INSIDE
REFER SERVICING TO OUALFIED SERVICE PERSONNEL
The llghtnrng flash w~th
arrowheadsymbol, wlthlnan
equilateral triangle, IS rn-
tended to alert the user to
the presence of un~nsulated
"dangerous voltage" wlthtn
the product's enclosure that
may be of sufflcrent magnt-
tude to constitute a risk of
electrlc shock to persons
The exclamation point
within an equilateral trangle
is intended to alert the user
to the presence of important
operating and maintenance
(servicing) instructions in
the literature accompanying
the appliance.
attachedat the output terminals.
In addition,the amplifierfeaturesa clipping
protectioncud.
This circuit does not add
distortionto the signal,
as doordmry"soft
clipping"circuits.
Instead, it reducesthe gain of
the amplifieronlywhen necessary to avoid long
term hard clipping.
'lhis circuit can be
selectivelydisabledby pressing the Protection
Defeat switch for
each channel desired.
The slottedcontrolknobs on the HTS5OSPA
are intended to requireinsertion of a coin to
change their settings.These knobs resist
accidentalchangesof position.
Two
LED'S on thefrontpanel illuminateto
indicatethepresence of an audio signal,and
eitheroperationof the protectioncircuit or
clipping.Power on
is indicated by the
illuminatedpower button.
Amplifier Architectme
To interface with the outsideworld,the
amplifier input connectorsare gold-plated
RCA
type phono @; output connectorsare gold-
plated five-waybin@ posts suitablefor use
with most
high-performance audio cables.
To receive and generatesignalsat the input
and output connectorsrespectively,scrupulous
care has been exercised in design and construc-
tion of the HTS5OSPA with highest quality
components used throughout.The power
amplifier circuit of each channel uses ahybrid
audiopower module construction.
This compact
assembly techquecombines semiconductor
chips,normally used in amplifiers
as separate
dwrete devices,intoa tightlycoupledunit on a
multilayer high-thermal-conductivitysubstrate.
The
high thermal conductivityof the base
substrateresults in a close thermal match of the
amplifier output circuitsto the voltage and
current
gain driverstages.Each discrete device
now tracks the otherdependent on power
dissipationin the output stage.
This is not
possible
with the discrete separatedparts using
normal amplifier construction.
Thus the
HTSSOSPA takes advantageof one of the benefi&
of monolithic integratedcircuitswhile still
retaining a discrete componenttopology
as part
of the hybrid amplifier module.The total
amplifier circuit combinesthe hybrid module
and specialcontrol circuitryto deliverhigh
currentand voltagewith low distortionand
precise controlof the amplifier circuit in
overload conditions.The output amplifiersin
each channel are complemented by signal
processing circuitswhich match amplifier
operationto the HTS loudspeakers.The total
combineslow noise FET operationalamplifiers,
high qualitysmall signalcapacitorsand resistors,
multiple computergradepower supply
capacitors,
glass epoxy circuit boards, and a
high currentlow noise,instrumentationgrade
toroidalpower transformer.
The result of these circuitrytechniques is
an amplifier of exactingspecifications,precisely
processing the input signaland accurately
matchingHTS5O SeriesLoudspeakerstoproduce
many years of enjoyment of the finest
film and
music sound stages.
HTSSOSPA FRONT PANEL CONTROLS
@ LWEL: For both Channel 1 and Channel
2, thenormalposition for the Level
control
is 0 (no attenuationfor all loud-
speakers.)
In the HTS Theater Reference
System,totalVolume level and Surround
level are controlled at the HTS Decoder
or its Remote Control.
In certain cases, other level settings
can also be recommended
1. To compensatefor room variations,
seethe Balance and Phasing section
of the HTS5300 Manual for specific
instructions.
2. For amore visceral low end in
theatricalpresentations,either turn
all level controlsto -3except for the
HTSSOSW Subwooferor turn all
levelscontrols to -6 except for the
Subwoofer. In both setups,leavethe
Subwooferchannel level conmlat 0.
The additional ultra-lowfrequency

emphasisin either alternatelevel
settingcan provide exceptional
excitement and even greater enjoy-
ment in home theater sound.
These slotted controlknobs are
intended to require insertionof a coin to
change their settings;they resist
accidentalchanges of position.
@ OPERATIONALMODE: The Operational
Mode switchesselect the signal process-
ing characteristicsof each amplifier
channelindependentlyto complement
the responsecharacteristicsand excur-
sionlimits of the HTS Loudspeakers:
HTSSOCF Center Front, HTSSOLRS Front
Left, Right and Surround,or HTS5OW
Subwoofer (selectable in Channel 1
only).These slottedcontrol knobs are
also intended to require insertionofa
coin to change their settings;they resist
accidentalchanges of position.
An excursionlimitingcircuit
continuouslymonitorsthe audio signal,
and modifies the low-frequencyresponse
onlywhen necessaryto prevent over-
excursionof the particular HTS
loudspeaker connected to that channel.
The characteristicsof this circuitry
depend on the OperationalMode
selected.This limiter circuit is always
activefor loudspeakerprotection.
There are twopossible OperationalModes
for the CF and LRS Loudspeakers,selected
accordingto whether or not a subwoofer is used
in the Home TheaterSoundSystem.When the
selector is in the CF or LRS position, the
amplifierlowfrequencyoutput cuts off at 80
Hz
to match the HTS5OSW Subwooferresponse;
these OperationalModes should
be selected
when the HTS system does include the
HTSSOW subwoofer.
When the systemdoesnot include the sub-
woofer,the selectorshould be in the CFxor
LRS, Mode. In these Modes, the amplifier low fre-
quency output extendsdown to60 Hz: the ex-
tended low-frequencyoutput signal is intended
to help compensatefor the lack of a subwoofer.
@CHANNEL1
FLAT: Outputhas no signalprocessing in
the signal path other than the defeatable
clippingprotection circuit.In Flat Mode
the HTSSOSPA is suitablefor
use with any
loudspeaker.
LRS: Output is tailoredto match the
HTS50LRS Loudspeakerwith low-
frequency cutoff at 80
Hz for use in a
system that
does includea subwoofer.
LRSx: Output matches HTS5OLRS Loud.
speakerwith low-frequencyextension
down to
60 Hz foruse in a system that
does not includea subwoofer.
CF: Output matchesHTSOCF
I~udspeakerwith low-frequencycutoff at
80Hz for
use in a systemthat does
includea subwoofet
CFx: Output matches HTS5OCF
Loudspeakerwith low-frequencyexten-
siondown to 55
Hz for use in a system
that does not includea subwoofer.
SW: Output matchesHTS5OW
Subwooferwith controlled low-frequency
boost and responsefrom
33 to 80 Hz.
This Moak is availableonlyon Channel I.
IPERAT IONAL MO
3
'cF
PROTECT101
MFEAT
priate position to control equalizationof
the output to match HTSSO Loudspeakers
or set to Flat for any other loudspeaker;
use the Channel
1 Level control to
determine the Bridged output level. In
Bridged Mode,the protection circuitry
for both channelsshould have the same
status(Protection Defeatpushbuttons
both out or both in). Totaloutput is 250
watts into 8 ohmsfrom
1 volt input.Refer
to Bridge Connectioninstructionsfor
specificdetailson connectingloud-
speakersfor hsOperational Mode.
@ cHANNEI.2
Identical to Channel 1 except the
extreme clockwiseposition in Channel
2
is Bridge instead of W.Explanation
follows.
functionahen Mode &lector is in
Bridge.) Use the Operational Mode
selector of Channel
1 set to any appro-
@ PROTECTIONDEW: Individual
pushbutton switchesfor Channel 1 and
Channel 2 disengagethe built-in
protection circuitrythat prevents long-
term hard clipping at the output. Under
BRIDGE: Inputfrom Channel 1 appears
at both Channel 1 and Channel 2 plus (+)
ournuts(Channel 2 Input does not
POWER: The pushbutton switch turns
power on and off.
most ordmrycircumstances,the
protection circuitsshould
be engaged
(Protection Defeat switchout.)

INDICATORS
@ POPER; Red light in the pushbutton
Power switchilluminatesto indicate
power ison.
@ SIGNAL: Green light illuminateswhen a
signal ispresent in the channel.
@ OVERLOAD: Red light illuminatesto
indicatelimitingwhen the Protection
Defeat switch
is out, or to indicate clip-
pingwhen the ProtectionDefeat switch
is pushed
in. In normal use with HTS5O
SURROUND LEFT SURROUND RIGHT,
SUBWOOFER OR BRIDGED.)
If speakerlocationsare reassigned,
remove the tabs by carefully prying one
comerout of the slot with apointed
instrument.The tab
can then be removed
with the hgertips. Take care not to
scratchor damage the amplifier front
hishwhen removing the indicator tab.
BACK PANEL
lo;dspeakers, the overloadlight will turn
on occasionallyfor high-leveldialogueor
music
peaks.
bindingposts that will accept any of the
following methods
of connection:bare
wire wrapped aroundthe post,bare wire
inserted through the hole in the post,
spade lug around thepost,pin connector
through the hole in the post, or banana
plug inserted in the jack These output
connectors will accommodate most high-
performanceaudio cables. (Gold ,080-
inch diameterpins solderedto the loud-
speakercables and insertedunder the
bindingpost hex caps [fastenedfinger-
tight] are the most reliable connection.)
To maintain proper speaker polarity in
the completed HTS system, it is
extremely importantthat eachplus (+)
amplifier output tedis connected
only to aplus speakerted,and each
minus
(-) amplifieroutput terminal is
connected only to a minus speaker
terminal.
@ INPUT CONNECTOss: Chml 1 and
Channel
2 input connectors are heavy-
dutygold-platedphono (RCA
type) jacks.
@ ~IWOR TM 0 SLOB: snap
the suppliedIndicatorTabs into these
slotswhen the loudspeaker
is connected
to the amplifier.The tabsshowthe
speakerlocationcorrespondmgto each
@ CHANNEL 1 OUTPUT: Both plus
and minus terminals are used in
normal two-channeloperationto
drivean HTSSOCF, HTSSOLRS,
HTSSOSW or any other loudspeaker.
Onlythe plus terminal of Channel
1
is used as the plusor high side
output connection to a loudspeaker
when the HTSSOSPA is in the
BRIDGED MODE
' .
Use only-&el 1 input when
BRIDGED MODE output isselected.
@ OUTPUTCONNECTORS All output
connectors are five-waygold-plated
@ CIIANNEL 2 OUTPUT: Both plus
and minus terminalsare used in
channel (LEFT,
RIGHT, CENTER,
:swum= -
- - - -
-----
-----
- ---
-----
tllr-
-
normal two-channeloperationto
drivean HTSSOCF, HTSSOLRS,
HTS5OSW or anyother loudspeaker.
Only the plus terminal of Channel 2
is used as the minus or lowside
output connection to a loudspeaker
when the HTSSOSPA is in the
BRIDGED MODE
' .
@ EXTERNAL FUSE: The lOA, 250 V Slo-
Blo fuse accessiblefrom the rear panel is
user replaceable.
If the fuse should blow,
disconnectthe power cord, and remove
the fuseholderand fuseby pressing
inward and rotatingcounterclockwise.
Replace the
fuse onlywith one of the
same
type, sameamperageandvoltage
rating.
If the fuse should blow a second
time, do not replaceit
again. Contact the
ShureService Department or other
qualifiedservicepersonnelto correct
the problem.
'See Bridged Connection instructions.

BRIDGED CONNECTION
If the amplifier is used in the Bridged MtKie, to
prevent the risk of electric shock the following
instructionsdescribethe only acceptable
method of connection(see illustration).
Voltages in the Bridged Connectionate
hazardous to
life. Make all amplifier-to-
speaker connectionswith
AC power discon-
nected. Refer senicing to qualitiedsenice
~ewnnel.
1.
Thread the speakerlead through the hole
in the suppliedconnector cover plate.
2.
Loosen the insulated red lockingcap on
the bindingpost, strip the end of the
speakerlead (approximately19mm [3/4
in.] ), and insert the strippedwire into
the hole in the bindmgpost. Twist the
strippedwire aroundthe post and tighten
the lockingcap.
Attach the coverplate over the binding
post terminal and fastenit
with the
suppliedscrews.
NOTE: To ensure correct Bridged Mode speaker
polarity,connect the plus
(+) terminal of
Channel 1only to the plus speaker terminal and
connect the plus terminal of Channel 2 only to
the minus
( - ) speakerterminal.
CONNECTION DETAIL
BRIDGED CONNECTION
SPECIFICATIONS
Frequency Response (Flat Mode ' )
20 Hz to 20 kHz + 0.5dB
PowerOutput
100watts minimum per channel into 8 ohms with lessthan 0.1 % THD
Input Impedance
100kilohms
Recommended Minimum Output Load Impedance
4 ohms
Input Sensitivity (Full Power Output in Flat Mode')
0 dBV (1.0V)
Dynamic Range
Greater than 100 dB from noise level to clipping (300 Hz to 20 kHz)
Power Requirements
120Vac f lo%,60 Hz
CeMcations
Listed by Underwriters LaboratoriesInc.
Overall Dimensions
102mmHx429mmWx356mmD(4x 16%~14in.)
Weight
12.3kg (27 lb)
'In other modes Frequency Response
and Sensitivityare tailoredto complement the individual
HTS Loudspeakers' FrequencyResponse and Sensitivity

TYPICAL SYSTEM ARRANGEMENT
TYPICAL SYSTEM CONNECI'IONS

Copyr~aht1983. Shore BI-others Inc
27A8165 (IA)
SHURE HTS
The Home Theater Sound Division of Shure BrothersInc.
222 Hartrey Avenue
Evanston,
l L 60202-3696
Pr~ntedIn U.S.A.