Warwick Pro Fet II User manual

WarwickServiceManual
ProFetII
ProFetIIFront
ProFetIIRear
Subjecttoalteration
GermanyHDBelectronic
LetzteÄnderung
Lastalteration02.1999

TableofContents
Page
1.General
2.Testingandregulating
3.Diagrams
4.BoardLayout’s
5.Oscillograms
6.AnalyserCurves
1.TechnicalSpecifications3.
2.Measuringdevices/methods3.
3.SafetyInstructions4.
4.Componentsandspares4.
5.Accuracyofmeasurements4.
6.Dismantlinginstructions4.
1.BasicConfiguration
2.Preamp5.
3.Poweramp6f.
1.Blockdiagram9.
2.Wiringdiagram10.
3.Circuitdiagrams
1.Preamp11.
2.Effects12.
3.13.
1.FET2VV114.
2.FETBU
3.
1.MP1-MP917.
5.
Protections
Parameters7f.
Poweramplifier
15.
PA400IR16.
⋅
⋅
1.FrequencyFilter18.
Page2

1.1TechnicalSpecifications
1.2Measuringdevices/methods
General
Mainsupply............................................................230V/115V
SpeakerOut............................................................250W/4Ohm
Input.......................................................................25mV
EffectsLoops..........................................................monoserial
send0dBu,600Ohm
return0dBu,10kOhm
Switches.................................................................groundlift
DIpre/post
Weight...................................................................11,5kg
Variabletransformer
Oscilloscop
Tongenerator
Multimeter
Stabilised-DCpwersupply(0V...10V)
Loadresistance(4ohms/250W)
⋅
⋅
⋅
⋅
⋅
⋅
⋅
⋅
⋅
⋅
FrequencyFilter
Headhpone..............................................................200Ohm,stereo
DirectOut...............................................................0dBu,600Ohm
Dimensions(W/H/D).............................................483mmx90mmx375mm
G
Page3
LOWBOOSTBASSPUNCHMIDLEVELATTACKTREBLEHIGHBOOSTMIDFREQ.
30Hz
+10dB75Hz -12,5...12,5dB230Hz -12...12dB250Hz bis7kHz-12,5dB bis+12.5dB2kHz -12...12dB6,5kHz -12...12dB25kHz -12...12dB

1.3Safetyinstructions
1.4Componentsandspares
1.5Accuracyofmeasurements
1.6Dismantlinginstructions
General
Pleasereadthesafetyinstructionsontherearpanelbeforeopeningthedevice.Aboveall,be
suretodisconnectthedevicefromthemainsbeforecommencinganyrepairwork.Special
caremustbetakenwhenworkinginthepoweramplifierareasasDCvoltagesinexcessof
>140V(poweramplifier)maybepresent.Thenormalprecautionsshouldbeobservedwhen
workingwithMOSelements
Anypartsthatprovedefectiveshouldonlybereplacedbyoriginalsparepartsastheuseof
substitutetypescouldresultinashiftingoftheoperatingpoint,withtheresultthatthecorrect
operationofthedevicecannolongerbeguaranteed.Thisisespeciallytrueintheareaofthe
poweramplifierwherecomponentshavebeenpreciselymeasured
Toremovethefrontpanel,firstloosenthe
screwshighlightedinblack.
Thenremovethepowersupplycableand
accompanyingcablefastenersfrom
insidethedevice.
Inordertodismantlethepoweramplifier,
loosenthescrewsmarkedingreyinFig.
2.Thenthecablesthatarepluggedin
shouldberemovedbeforethesoldered
cablesareseparatedfromtheircontacts.
Themeasurementsdocumentedinthecircuitspecificationsaretobeunderstoodas
approximatevalues.Anydeviationfromthestatedvaluesshouldnot,however,exceed10%.
Theoscillogramsforthemeasurementpoints(exceptMP7)beginatpage17.
FrontPanel
PowerAmplifier
Fig.2.:Positionofthesrews
a)frontpanel;b)base;c)rearpanel
a)
b)
c)
Page4

UsedMeasuredevices.
Generator:Wavetek
Model188-S-1257
4MHzSweep/FunctionGenerator
Oscilloscop:Goldstar
OscilloscopeOS-7040A40MHz
2.1BasicConfiguration
2.2Preamp
Testing/Regulating
Bild3.:ProTubeIIBasicconfiguration
Testingthefilter
Totestthefilters(LowBoost,Bass,Punch,Mid,
Attack,Treble,HighBoost)atonegeneratoris
connectedtotheinputandthecontrolsofthe
aresettotheirLINEARconfiguration.The
signalismeasuredusinganoscilloscopeatthe
output.
Thefiltertobetestedisfirstturnedallthewaytothe
right(seethe""table)andthenallthewayto
theleft(seethe""table).WhentestingtheMid
filter,youalsohavetosetthecutofffrequency(250,
7k).
Oncethefiltertobetestedhasbeenactivated,thefrequencywiththegreatestdegreeof
amplificationmustbedetermined.Thisisthencomparedwiththedataintheadjacenttable
andshoulddeviatebynomorethan15%.
Pro
FetII
EffectsSend
Boost
Cut
±
InstructionsconcerningtheLimiter,Gain
TotesttheseLEDs,thecontrolsofthemustbeintheirLINEARconfiguration.
TheswitchinglevelsoftheseLEDsaresetoutinthecircuitdiagramforthepreamp.
TotesttheGainandLimiterLED,asinewavesignalofapproximately1kHz,variableinits
amplitude,isappliedtotheinput.
Thesignalismeasuredusinganoscilloscopeatorof.Theinputsignalisthen
increaseduntiltheswitchingpointoftheyellowLEDisreached.Themeasurementtakenat
isthencomparedwiththelevelgiveninthecircuitdiagram.Theinputsignalisthen
increasedstillfurthersothattheOKandClipLEDscanbetestedinthesamemanner.
TotesttheLimiter,firstactivateitandthenproceedinthesamemannerasbefore.
ProFetII
PIN-76IC1
IC1
NOTE:Aneffectiveexaminationofthecanonlybe
carriedoutusingafrequencyanalyser.Thegraphs
neededfortheevaluationbeginonpage18.
ProFetII
ToconductatestonaWarwickwiththe
measuringdatagivenbelow,youmustfirstsetthe
variableparametersinthechannelstripstowhat
willhenceforthbedescribedastheirLINEAR
configuration.
ProFetII
Page5
Gain\Master
Limiter\Mute
LowBoost\HighBoost
Bass\Punch\MidLevel\
Attack\Treble
10
OFF
OFF
0
Input
Vss/mVFilter OptionsFilterFrequency f/HzBoostCut (+6)U/Vss(-6)
10
10
10
10
10
10
10
10
30
70
230
250
7,2k
2,1k
6,8k
25k
1,4/
1,592m
1,588m
1,880m
1,780m
1,5
1,6
1,8
96m
/
96m
LowBoost
Bass
Attack
Treble
HighBoost
Punch
MidLevel(250)
MidLevel(7k)

2.3
Short-circuitprotection
Poweramp/ProtectionsTesting/Regulating
Whenthedeviceisswitchedon,thereshouldbeanoticeabledelaybeforeitpowersup.
Youshouldbeabletoheartherelayoperating.Thelengthofthedelayshouldbeabout
twoseconds.
ThefollowingprocedureisusedtotestthecircuitthatprotectsagainstDCvoltageatthe
output:Switchoffthedevice
Removedfusesto()
ConnectamultimetertotheemitteroftransistorT17()
ConnectastabilisedDCsource()totheoutput
Switchonthe
NowslowlyraisetheDCvoltageatthe'soutput(positiveandnegativetests)until
thedeviceisseentoswitchoff(theMuteLEDwillilluminateandtherelaywillswitchoff).
Whentheswitch-offoccurs,thevoltageatT17shouldbec.0.6V.
IfthehasnotswitchedoffbythetimetheDCsourcevoltagereaches3V,thereisa
fault.
Notethatthereisanelectrolyticcapacitorintheprotectivecircuittoensureasluggish
response.Thatiswhyitisessentialtoincreasethevoltageslowly.TheexternalDCvoltageis
interruptedwhentherelayswitchesoffandafterashortinterval,duringwhichthepower
amplifierwillbeinStandbymode,itwillreturntoOperatingmode
Beforeperformingthistest,thestabilisedDCvoltagepowersupplyshouldbesetto+8V.
ThesimplestwayofconnectingtheEarthistoconnectit
tothe(Minus).Theotheroutputofthe
voltagesourceisconnectedtoNTC2.(
)
Whentestingtheshort-circuitprotection,a4ohm(250W)load
resistanceisattachedtotheoftheamplifierandan
additional1(250W)ohmloadresistancetotheearthofthe
output(seeFig.4)Asinewavesignalofc.1kHzshouldbe
appliedtotheandincreaseduntilthe
oscilloscopeattheoutputshows
DCVoltageProtection
Temperaturecontrol
⋅
⋅
⋅
⋅
⋅
Si1Si2
ProFetIIProFetIV
ProFetII
SpeakerOut
SpeakerOut
EffectsReturn
takecaretodischargetheinputcapacitors
1Vrange
setto0V
Attention:one
pinofNTC2isconnectedtoEarth
.
Thefollowingtableshowshowtheprotectivecircuit
reactsatvariousoperatingpoints.
Heretooitshouldbeborneinmindthatthestated
voltagevaluesareapproximationsandavariationof+
or-10%ispermissible.
Page6
FanON
StandbyON
StandbyOFF
FanOFF
6V
7,5V
3,5V
4,5V
Fig.4.:Short-circuittest
(SPEAKEROUT)
TTENTION:Ifitbecomesneccesarytoreplaceabrokenpoweramptransistor,it´sstrongly
recommendettouseoriginalsparepartssuppliedbythemaufactureronly.Also,
evenincaseofONEbrokenpoweramptransistor,youshouldreplacethewhole
set,whichmeans2xor2xIRFP9240IRFP240.

2.3Poweramp
2.3Poweramp/Parameters
Testing/Regulating
front
Master:10
Fig.5.:requiredsettings
72V(peak-to-peak)(Master:).Theoutputshouldthenbeconnectedwiththe1ohm
resistance.Directlyafterwards,theshouldswitchtoStandbymodeandremain
thereuntilitisswitchedoff.
ThequiescentcurrentisbalancedusingtheparallelconnectedresistorsR1||R2.
TosetthequiescentcurrentadigitalmultimeterisalsoconnectedtotheresistorsR1||R2to
measurethevoltagedrop.
Themeasuredvalueshouldfallatleastwithintherange1.0mV-2.0mV.Ifthisisnotthecase,
itcanbetrimmedusingthepotentiometerP1.
Whentakingthesemeasurements,takecarethatthereisnosignalattheinputandnoloadat
theoutput.Themeasurementsshouldbetakenatroomtemperatureandassoonaspossible
afterswitchingonthedevice,aswarmingofthepoweramplifiercouldcausedeviations.
10ProFetII
Trimmingthequiescentcurrent
Limitingtheoutputsignal
Forthistest4ohms(450Wshortterm)loadresistanceisconnectedtothe.The
inputsignal,asinewavesignalwithafrequencyof1kHzandanamplitudeof0...5V(peak-to-
peak),isappliedtothe.Forthesemeasurements,thenecessaryfrontpanel
settingsareasfollows
Thesignalattheisslowlyincreasedto1,6V(peak-to-peak).Seethetablefor
thereactionoftheinputsignal.
SpeakerOut
EffectsReturn
EffectsReturn
NOTE:I ftheloadresistancecanbevariedto2ohms,theoutputstabilitycanalsobe
tested.Forthispurpose,theoutputmustbeconnectedtothe2ohmsload
resistance,butthepoweramplifiermustnotbeallowedtoswitchoverto
Standbymodebefore15Veff.
Page7

2.3PowerampTesting/Regulating
Thereshouldbenolimitingoftheoutputsignaluntilthe
inputsignalreachesaround1,6V(peak-to-peak).
Iftheinputsignalisincreasedbeyondthispoint,somelimiting
oftheoutputsignalshouldbeobservableontheoscilloscope.
Frequencylinearity
Ground/Lift
Thefrequencylinearityistestedusingatonegeneratorandvoltagemeter.Theinputsignalis
connectedtothesocketontherearpanelofthe.Forthe
measurementtobecarriedout,itisessentialthatthesignalbevariablebetween
100Hz...1kHz...10kHz(switchedissufficient).Aloadresistanceof4ohms(250W)anda
voltagemetershouldbeconnectedtotheoutput.A1kHzsignalshouldthenbedirectedtothe
andthecontroladjustedsothatanoutputsignalof28V(peak-to-peak)(10
Veff)ismaintained.
Thefrequencyoftheinputsignalshouldbeswitchedto10Hzandthento10kHz.Thevalue
oftheresultantoutputsignalshouldnotdeviatebymorethan10%fromitsinitialvalue.
Finallythefunctionoftheswitchshouldbe
checked.Forthispurpose,amultimetershouldbeswitched
betweentheearthsofthechassisandthedevice(Interior
partition-(Minus)).Theresistancevaluesfor
thesettingofthearesetoutinthenearbytable.Thevalueintheposition
canvarywidelyasaresultofthetransientresistanceoftheswitchingcontacts.Consequently
valuesupto5ohmsarepossibleandnormal.
EffectsReturnProFetII
EffectsReturn
Ground/Lift
SpeakerOut
Ground/LiftGround
InputOutput
1,6Vss
1kHzca.:96Vss 34V
1kHz
4
eff
Ω
Ground
Lift
0Ω
1M Ω
Page8

3.1BlockdiagramDiagrams
Page9

3.2WiringdiagramDiagrams
Page10

3.3.1PreampDiagrams
Page11
221
LED
2k21
LEDMUTE
22k
MUTE
MUTE
10k
10k
10k
10k
10k10k
10k10k
10k10k
10k10k
10k
10k10k18k2
NE5532
22k1
1M
2k21
22p
100k
22k1
22k1
2k21
2k21
22k1
TL074
TL074
TL074
MUTE
475
10k
GND
PHONE
EFF RET
EFF SEND
LINEOUT
TUNEROUT
GND
-24V
+24V
GND/PAPAIN
LEDMUTE
33k2
15k
4k753k32
1M
5k62
2,2M
2k21
47k5
2k21
GND
GND
LP-Rand
2k21
SwitchMUTE
Switch
10k
MP2

3.3.2EffectsDiagrams
Page12
EFFECTSEND
EFFECTRETURN
EFFSEND
EFFRET
LINEOUT
TUNEROUT
LINEOUT
TUNEROUT
PHONE221
Rel
rel1
rel2
GROUNDFREE
100n
1M
X1
X1
X1
X1
X1
X1
GND
X1
PHONE
X2
+REL
REL
X2
GND
PCBEdgePCBEdge
Chassis

3.3.3PoweramplifierDiagrams
Page13
4k75
4k75
4,7
10k
47k5
10k
100n
22k1
475k
22k1
22k1
10k
47k5
1k
MUTELED
+24V
-24V
GND
INPUTGND
REL+REL
PHONE
4002
15k4
4k75?
4002
0,22
0,22
0,22
0,22
121
121
1k
121
825
475
27k48k25

4.1FET2VV1BoardLayout
Page14
------------
+
+
+
+47u47u
TL072
NE5532
kurz
BC558
4k75
10k
22n
100k
10k
10k
2k21
68n
10k22k1
1M
10k10k
10k
330n
10k
10k
------
2,2n10k10k
10k
1n10k10k
10k
2k21
1M
5k62
2,2M
------------
100k
4148
------------
------------
TL074
------
3k32
3k32
4148
4148
4148
22k1
100k10k
100k
100k
47,5
22k1
47,5
2k2122k14148
2k21
------------
1k1k
2k21
------------
------------
------------
100k
3k9k
2k21
------
2k21
2k21
221
22k1
------------
------------
22k1
1M
22k1
2k21
33k2
2k21
3k32
2k21
4k75
------------
3k32
3k32
3k32
4V7
4V7
4V7
3k32
4V7
IC1
IC4
IC5
LEDgn

4.2FET2BUBoardLayout
Page15
1M
100n

4.3FET2PABoardLayout
Page16
6,3AT
IRFP240IRFP240
+
+
NTC10k
IRFP9240IRFP9240
NTC100kCermet
4k75
47k5
------------
22k1
8k25 ------------
475k
1k22k1
1Ohm
4,7Ohm
0,22 Ohm
332
4002
22k1
100n
332
4002
10k
27k4
500
4093
1k4002
4002
100n
100n100n
0,22 Ohm
22k1
0,22 Ohm
0,22 Ohm
100
Philips
P1
SI2
NTC2
NTC1
T22 T23
T24 T25
IC9
[+]
+
-
+
-
AC
AC

Page17
5.1MP1-MP6Oscillograms

6.1FrequencyFilterAnalyserCurves
Page18