JBL 5152 Manual

JBL
5152
INSTALLATION
AND SERVICE
MANUAL

ArchitecturalSpecifications
The preamplifiershallhavetwoinputchannelswith
separately adjustablegaincontrols accessible onthe
front panel. Each inputchannelshallaccommodate
an unbalancedhighimpedancemicrophoneorline
input,ora balancedhighorlowimpedancemicro-
phoneorlineinputwithanoptional accessory plug-in
transformer.Oneinputchannelshallalsoaccom-
modatea magneticphonocartridgeinput.
The preamplifiershallbecapableofoperatingin
eitheroftwomodes.IntheMIXmode, both input chan-
nels shallbemixedtogetherwith full gainavailableto
each atalltimes.Inthe OVERRIDE mode, CHANNEL
1 shallbeswitchedonand CHANNEL 2 shallbe
reduced ingainby15dBmwhenthe TRIP terminal
is connectedtoGND.
The preamplifiershallbecapableof+18dBm output
level into anunbalanced600Oload[directoutput}
and + 24dBm output level into a balanced600Oload
(transformeroutput].Frequencyresponseintheaudio
bandshallbeflatwithin±1dBanddistortionshallbe
<0.2%,30Hz-20kHz.Thepreamplifiershalloccupy
onestandardEIArack space andshalloperateon
100-120 VACor200-240VAC,50/60Hz.
Installation
The 5152issuitableeitherforrackmountinginone
EIA standardrack space (12%2"3 withoutadditional
bracingorventilation,orforcounter-topplacement.
Allexternalconnections, MIX/OVERRIDE switchand
matching/bridgingtransformeroptionsareavailable
ontherearpanel,Figure1.
NOTE: Alllow-levelamplificationcircuitrycanbe
adversely affectedbystrongmagneticfields.Forthis
reason, itisrecommendedthattheunitbelocatedat
least seven inchesfromanypoweramplifieror
similar sourceofelectromagneticradiation.
Ventilation
The 5152generatesminimalheatduringnormal usage.
However, becausetransistorsareheatsensitive,the
5152 shouldnotbeplacedadjacenttoheat-generating
equipmentorin areas wheretheambienttemperature
exceeds 50°C(122°F)withoutadequateventilation.
Figure 1
PRODUCT SPECIFICATION
DirectOutTransformerOut
Gain
Low Impedance62dB68dB
Microphone
(with5195transformer]
HighImpedance45dB51dB
Microphone
[notransformer]
Line 25dB31dB
[with 5195transformer]
Line 21dB27dB
(notransformer]
Phono47dB@1kHz53dB@ 1 kHz
Maximum Output Level
Balanced +24dBm@
600 a
Unbalanced+18dBm@
600 O
Frequency Response20Hzto20kHz,+0,-1dB
(@ +18dBm]
THD <0.2%,30Hzto20kHz
Equivalent Input Noise-125dBref.0.775V unweighted,low
impedancemicrophone input, 150O
source, eitherchannel,maximumvol-
ume,20kHzequivalentnoisebandwidth
Input Impedance
Low Impedance1 kO
Microphone
HighImpedance56kO
Microphone
Line 15kOOr600O with terminatingresistor
Phono56kO
(channel 2 only]
Power Requirements120/240V AC,50/60Hz
Power Consumption6 W,normal
MaximumAmbient50°C 122°F
OperatingTemperature
Clearance Dimensions
FrontPanel44mmx483mm12%2inx19in
DepthofControls20mm% in
DepthBehindPanel216mm8/2in
(notransformer]
DepthBehindPanel251mm9%in
(with5195transformer]
Mounting 1 EIAstandardrack
space
Weight
Net3.6kg8 lb
Shipping4.8kg10.51b
Accessory 5195
matching/bridging
transformer

InputConnections
Inputconnectionsmaybeeitherdirect-coupledor
transformer-isolatedattheinputterminal strip,TB301,
orthetwo RCA-type phono jacks, J301 and J302,
Figure 1.Directcouplingisaccomplishedbyconnect-
ingtheinnerleadofa shieldcabletoHIof INPUT 1
or INPUT 2 andtheshieldleadtoLOof INPUT 1 or
INPUT 2,Figure3.Fortransformer-isolatedinputs,
JBL 5195matching/bridgingtransformersmustbe
plugged into the9-pin sockets, XT301 or XT302.
An assortmentofjumpersisincludedwiththeunitto
facilitateallinterconnectionsshownin Figures 3 and6.
ModeSelection
The preamplifierisdesignedtooperateeitheroftwo
modes, selectablebymeansofthe OVERRIDE/MIX
switch, asshowninFigure1.
MIX-INPUT 1 and INPUT 2 aremixedasdetermined
bysettingsoftheirlevelcontrols,with full gain avail-
able at each input.
OVERRIDE-INPUT 1 isnormallymutedand INPUT
2 isfullyoperational.Whentheoverrideistriggered
bygroundingthe TRIP terminalof INPUT 1, INPUT 1
becomes fullyoperationaland INPUT 2 isreducedin
gainby15dB.
Balanced
Low Impedance
Microphoneor
HighImpedance
Line
Unbalanced
HighImpedance
Microphone
or Line
Figure 2
Figure 3
Balanced
Low Impedance
Line
Balanced
Low Impedance
Line with14dB
Extra Gain
[Input Level less
than-20dBm]
Figure 4
Figure 5
Figure 6
Phono Jack
May be Used
forUnbalanced
HighImpedance
Microphone, Line
orMagneticPhono
[channel 2 only]
Figures 7aand7bshowtheoptional output wiringconnections.
DIRECT OUTPUT
OutputConnections
Either transformer-isolatedordirect output connec-
tionsareprovidedatthe OUPUT terminal strip,TB302,
Figure 1.
Figure 7a
BALANCED OUTPUT
Figure 7b

The following proceduresaredesignedto assist inthe
isolationofmalfunctions.Theoperationsdescribed
shouldbeundertakenonlyafteraninvestigationofall
external connectionsandadjustmentshasindicated,
beyondreasonable doubt, thattheproblemisactually
within the unit.
Component Access
The 5152containsonlyoneprintedcircuitboard.All
componentsaremounteddirectlyonthecircuitboard
with theexceptionofthe output transformer,power
transformer, on/off switch, pilot lamp,levelcontrols,
supplyvoltageselectswitch, input and output terminal
strips, mix/overrideswitchandthe 9-pin sockets.
To reachthecircuitboardfortesting,servicingor
input selection,onlythetopcovermustberemoved
(eightsheetmetal screws}. Removalofthecircuit
board from the chassis requires popping outsix snaps.
VoltageConversion
The 5152canbeoperated from eithera 100-120VAC
or200-240V AC,50/60Hzsource.The SUPPLY
VOLTAGE SELECT switch, S301, convertsthe unit
from oneoperatingvoltagerangetotheother.Usethe
following procedurestoconvertthepreamplifiertoa
differentvoltagerange:
1. Disconnectthe5152 from thepowersource.
2. Slidethe SUPPLY VOLTAGE SELECT switchtothe
appropriatelinevoltagerange.
WARNING
THIS SECTION OFTHEMANUAL
CONTAINS SERVICE INSTRUCTIONS
FOR USEBY QUALIFIED SERVICE
PERSONNEL ONLY.
3. Changethelinecordandattachmentplugtomatch
thepowersourcereceptacleorusea 120-to-240V
adapter(notprovided}.Theattachmentplugand/or
linecordusedfor240V ACmodeintheU.S.,
Canada and Japan shallbe both U.L.listedand
C.S.A. Certified.Foruseinothercountries,linecord
selection shouldbebasedonlocalregulations
governing240V AC50/60Hzsupplysource.
U.L. and C.S.A. VoltageWiringCode
Country Switch,Switch,Ground, Wire
S301, S201,E401Color
TerminalTerminal
U.S. and1 - - Black
Japan - 1 - White
-- YesGreen
Europe 1 - — Blue
-1 — Brown
-- Yes Green/-, oilow
CAUTION: This unit maybedamagedifoperated
with thesupplyvoltageselectswitchsetincorrectly
forthelinevoltageapplied.
Selector Switch
Table 1 showsthevarious input sources, terminations
and jumperoptionsforthe5152.SeeFigures2-6for
available interconnections.
TABLE 1
InputSelector
Transformer
Switch Position
Accessory
Socket Jumper Termination
Input
Connector
(InternalAdjustment)
Transformer
Connections
Resistor
Balanced
Low Impedance
Terminal
MIC
5195
None None
Microphone
Strip
Unbalanced
HighImpedance
Terminal
MIC
None
4-5
None
Microphone
Strip
7-9
Phono Jacks
MIC
None 3-9 None
(Channel 2 only)
Balanced
HighImpedance
Terminal
LINE
5195
None None
Line
Strip
Balanced
Low Impedance
Terminal
LINE
5195
None 620-ohm
Line
Strip
1/2-watt
Balanced
Low Impedance
Line with 14dB
Terminal
MIC
5195
None 1800-ohm
Extra Gain
Strip
K-watt
(Input Level Less
Than -20dBm}
Unbalanced
HighImpedance
Terminal
LINE
None
4-5
None
Line
Strip
8-9
Phono Jacks
LINE
None 3-9 None
(Channel 2 only)
Magnetic None
Phono Phono
Jacks
PHONO
None 3-9 None
(Channel 2 only]

OutputConversion
For 150O output, the following procedureshouldbe
used toparallelthewindingsofthe output transformer,
T402, Figure8.
1. Disconnectthe unitfrom thepowersource.
2. Clipthe BLUE and VIOLET output transformerleads
from theprintedcircuitboardatpoints#27and#28.
3. Solderthe BLUE transformerwiretothe GREEN
wireattheOUTPUTterminalstrip,TB302, markedHI.
4. Solderthe VIOLET transformerwiretotheG RAY wire
atthe OUTPUT terminalstrip, TB302, markedLO.
The 5152hasbeendesignedsothat both thedirect
andtransformeroutputsmaybeusedsimultaneously.
ProofofPerformance
Allperformancechecksarein-cabinetproceduresto
beusedforcheckingspecificationsafterrepairorfor
incomingqualitycontrolinspection.
NOTE: Allmeasurementsshouldbemade with the
unit andtestequipmentpowercordsconnectedtoa
normal120VACor240V AC50/60Hzlinesource.
WARNING
THISSECTION OFTHEMANUAL
CONTAINS SERVICEINSTRUCTIONS
FOR USEBY QUALIFIEDSERVICE
PERSONNEL ONLY.
FIGURE 10, REVERSE RIAA
EQUALIZATIONNETWORK
DONOTUSE SHIELDEDCABLE ATTHE OUTPUT OF
THE FILTER;STRAPDIRECTLY TOTHE INPUT OF
THE VOLTMETER,
ACVOLTMETER
ToMIC
CHANNEL
UNDER TEST
FIGURE 12,40dB,
600 n PAD
The following testequipmentisrecommended:
AUDIO TESTOSCILLATOR
HARMONIC DISTORTIONANALYZER
40 dBPAD[150O)
REVERSE RIAA EQUALIZATION NETWORK
20 kHz FILTER
ALTERNATE 40dBPAD[600O)
Krohn-Hite4100,orequivalent.
Hewlett-Packard model333A,orequivalent.
See Figure9
See Figure10
See Figure11
See Figure12
Figure 8.
FIGURE 9,40dB,
150 n PAD
HEWLETT
PACKARD
333A OR
331A
FIGURE 11,20KHZ FILTER
ALTERNATEOSCILLATORSETUP: Z=600n
20 KHZ FILTER
OSCILLATOR IN ToPHONOIN
150A BAL
KROHN-HITE
4100
To MIC
CHANNEL
UNDER TEST
OSCILLATOR
40 dBPAD
KROHN-HITE
4100
OSCILLATOR 40dB
PAD

Frequency Response
(20 Hz-20kHz,+0,-1dB@ +18dBm, into 600O
Ref. 1 kHz.)
Table 2 outlinesthetestset-upandsequencefor
measuringfrequencyresponseofthe5152.
JUMPERS
Figure13
WARNING
THIS SECTION OFTHEMANUAL
CONTAINS SERVICE INSTRUCTIONS
FOR USEBY QUALIFIED SERVICE
PERSONNEL ONLY.
4. Setthe CHANNEL 1 or CHANNEL 2 levelcontrol,
dependingonwhichchannelisundertest,to
maximum.
5. Settheoscillatorlevelfora +18dBm(directoutput)
or+24dBm(transformeroutput).
6. Measurethe distortion ofthepreamplifierat30Hz,
200 Hz,2 kHzand20kHz.
HEWLETT
PACKARD
333A
FIGURE 14,THD TEST
SET UP
MicrophoneEquivalentNoise
(-125 dBRef.0.775V unweighted,150Osource
20 kHzequivalentbandwidth).
Using thetestset-up,Figure11or12:
1. Setthe MIC/LINE or PHONO/LINE/MIC switch
toMICandthe MIX/OVERRIDE switchtoMIX.
2. Installa 5195transformer into INPUT 1 or INPUT 2.
3. Setthe CHANNEL 1 or CHANNEL 2 levelcontrol
tomaximumandthechannelnotundertestto
minimum.
4. Settheoscillatorto2 kHzandadjustthe output
level ofthe5152to0 dBm.
5. Measurethe input signal.Typicalreadingsare-71
dB, indicatinga gainof71dB.
6. Installthe20kHz filter, Figure11.
7. Disconnecttheoscillator from thepreamplifier.
8. Measurethenoiselevelatthe output ofthe5152.
Typical readingsare-54dBm.
9. Addthe input levelandnoisemeasurementto
calculate theequivalent input noise.
EXAMPLE -71dBRef.0 dBm INPUT LEVEL
-54 dBRef.OdBm NOISE LEVEL
-125 dBRef.OdBm EQUIVALENT
INPUT NOISE
10. Thecalculatedequivalent input noisefigureshould
be-125dB(Ref.0 dBm)orbetter.
DC VoltageMeasurements
AllDCvoltagemeasurementsare with respectto
groundandaremadeusinga Fluke8000A with a line
voltageof120V AC.
Voltages shown with tworeadingsontheschematic
indicatethetwostatesofthe TRIP DETECTOR and
FET GATE whenproperlyoperating.
EXAMPLE TRIP DETECTOR
+ 0.460V NOT GROUNDED
+ 86.9mVTRIP DETECTOR
GROUNDED
TABLE 2
AC VOLTMETER OR
HARMONIC DISTORTION ANALYZER
Figure 1 + THDtestsetup.
THD
(<0.2%,30Hz-20kHz).
Using thetestset-up,Figures9 and14:
1. Setthe MIC/LINE or PHONO/LINE/MIC switch
to LINE.
2. Setthe MIX/OVERRIDE switchtoMIX.
3. Installjumpersbetweenterminals#4and#5and
betweenterminals#8and#9ofeach 9-pin socket,
XT301 and XT302, Figure13.
NOTE: TouseTable2,read down and
across. Numbersunder LINE, MICand
PHONO representtestsequence.
Frequency ResponseTestand
OperationalSequence.
Line LineMic Phono
Connecttestoscillatorto input.
1 1
Connecttestoscillatorto input using
1
Figure9 orFigure12.
Connecttestoscillatorto input using
1
Figure10.
Set MIC/LINEorPHONO/LINE/MIC
2
switchtoMIC.
Set MIC/LINEorPHONO/LINE/MIC
2 2
switchto LINE.
Set PHONO/LINE/MICswitchtoPHONO.
2
ConnecttheAC voltmeter anda 620O,
3 3 3
1 W loadresistoracross output terminals
marked DIRECT andGND.
ConnecttheAC voltmeter anda 620O,
3
1 W loadresistoracross output terminals
markedHIandLO.
Set CHANNEL1 orCHANNEL2 level 4 4 4
control tomaximum.Setthetestoscillator
to2 kHzandadjustthe amplitude toindicate
+ 18dBmacrossthe DIRECT andGND
terminalsofthe OUTPUT strip.
Set CHANNEL1 orCHANNEL2 level 4
control tomaximum.Setthetestoscillator
to2 kHzand adjusttheamplitudeto indicate
+24dBmacrosstheHIandLOterminals
ofthe OUTPUT strip.
Voltagegainofthesystemcanbechecked
5 5 5 5
by substituting thevalueintheformula:
Av(db)=20Loq10ClO
Input voltageofthesystemcanbe
measuredbyconnectingtheAC voltmeter
6 6 6 6
attheINPUTterminals.

JBL
ProfessionalDivision
James B. LansingSound, Inc., 8500BalboaBoulevard, Northridge, California91329,U.S.A.
50705 PTM515211/78 PRINTED IN U.S.A.