Rane FVL 22 Service manual

OPERATING/SERVICEMANUAL FVL22
REMOTEVCA/LIMITER
QUICKSTART
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There are two ways to connect audio to the FVL 22, #6 terminal strips or Patch I/O points. To
usetheterminals,attachthebalancedlinestothe“+”,“–”,andSHIELDGROUND terminals.
To run the FVL 22 unbalanced, attach the positive lead to the “+” terminal and leave the “–”
terminalopen. To use the FVL 22 as an external level control/limiterfor a mixer or other device
with tip = send,ring = return insert points, simple use the PATCHI/O ¼"TRSjack. Note:
PATCHI/Oisanunbalancedsignal.Usetwoconductorcablewithshield.
Installyourremotecontroldevice (5k to100klineartaperpotentiometer,voltageramp,or
switch) and run two or three wires to the FVL 22. If you are using an external voltage, run one
wire per Channel to the V1 terminal for Channel 1, V2 for Channel 2, and a ground wire to
COMMONGND.Touse theprovided10VDCreference,connectasecondwirefrom VREFl or
VREF2 toyour pot or switch. Refer to the wiringdiagrams on theback page ofthis manual.
TheVCA’s in theFVL 22provide maximumattenuation ofthe signal levelwhen agiven
voltageisdetectedbetweenVlorV2 and COMMONGND.Reducingthisvoltagewith a pot,
ramp,or switch increases the audiosignal level. (0volts or open= VCA fullon.)
Tocalibrate:settheremote pot,ramporswitchto it’smaximumvoltage.Adjustthe VOLT-
AGECALIBRATION controluntilthegreenCALindicatorislit.
RotatetheLIMITER threshold control tothe level younever wish toexceed at theoutput.
TheAUTO-SLAVE switchpositionlocksthelimitercontrolcircuitryforstereoapplications,
limitingbothChannelsequallywheneitherChannelgoesintolimit.
Uponcompletionofthesetupprocedures,usethesuppliedholeplugstopreventunautho-
rizedadjustments.
Neverconnect anything except an approvedRane AC Power supply tothe thing that looks
like a red telephone jack on the rear of the FVL 22. This is an AC power input and requires
specialattention if youdo not havea power supplyexactlylike theoneoriginally packed with
yourunit. Ranemodels FRS8, RAP10 orVC 18 power supplies areacceptable aswell. Please
seethefullexplanationofpowersupplyrequirementselsewhereinthismanual.
SYSTEMCONNECTION
WhenconnectingtheFVL22toothercomponentsforthe
firsttime, leave the power supply for last. This allows for
mistakestobeidentifiedbyvisualinspectionandcorrected
beforepoweris appliedand it becomestoo late.
INPUTSandOUTPUTS ontheFVL22areconnected
viaterminal strips or the PATCHI/O jack. Usingthe termi-
nals,attach the balanced lines to the “+”, “–”, and SHIELD
GROUNDterminals.ToruntheFVL22unbalanced,attach
the positive lead to the “+” terminal and leave the “–”
terminalopen. To use the FVL 22 as an externalprocessor for
a mixer of other device with tip = send, ring = return insert
points,use thePATCH I/O¼" TRSjack witha twoconductor
shieldedcable(thePATCHI/Oisunbalanced).
EXTERNALVCACONTROL.TheVCA’sintheFVL
22providemaximumattenuationofthesignallevelwhena
voltageisdetectedbetweenV1andV2andCOMMONGND.
Reducingthisvoltagewithapot,voltageramp,orswitch
increasesthe audiosignal level. (0volts oropen = fullVCA
on.)Thisvoltageis providedbytheVREF terminalonthe
FVL22or derivedbyexisting voltagesourcesat theremote
devicelocation.Refer tothewiring diagramsonthe lastpage
ofthismanual.
POWERINGUP.Agoodvisualinspectionoftenelimi-
natesdisastersbeforeapplyingpower.Itcannotbeoverstated
howimportant itis to usethe correctpower supply withthis
andall Flex products. The RS1 single ACpower supply
(includedwith eachmodule) as wellas theRane FRS 8,RAP
10and VC 18 power supplies are the only suppliescertain to
workproperlywiththe unit.Ifanothersupply isconsidered,it
must be an AC supply. It must have an 18 to 24 volt center-
tappedoutput and be wired to a 6-in mod connector in
accordancewiththerequirementsoftheRanestandard.

FRONTPANELDESCRIPTION
1.LOWCALIBRATIONLED. TheVCA’sintheFVL22attenuatethe
mostwiththehighestvoltageacrossV1andCOMMONGND.Setting
theremotepot, ramporswitch toprovideits highestvoltagereadies the
FVL22 forcalibration. Duringcalibration, ifthis LEDis on,adjust the
VOLTAGECALIBRATIONcontrolclockwise,untiltheCALindicator
comeson.
2.CALLED. ThisLEDilluminateswhenthemaximumvoltageispresent
betweenV1andCOMMONGNDandthecalibrationisjustright.
3.HIGHCALIBRATIONLED. Duringcalibration,ifthisLEDison,
adjustVOLTAGECALIBRATIONcounterclockwise,untiltheCAL
indicatorcomeson.
4.VOLTAGECALIBRATIONADJUST. Usethisscrewdriver-adjust
controltosettheVCAcircuitry calibrationwhentheexternalvoltage at
V1is set to its maximum level.
5.LIMITTHRESHOLDLED. WhenthisLEDilluminates,thepreset
levelthresholdofthelimiterhasbeenexceeded.
6.LIMITERADJUST. Rotatethisscrewdriver-adjustcontroltocalibrate
thepoint at which the output limits. Theinner ringof numbersshow the
angletorotate thiscontrol forbalanced operation,the outer ringfor
unbalancedoutputlevels.
7.AUTO-SLAVESWITCH. IntheINDEPENDEDENTposition,each
LimiterChanneloperatesseparately.IntheAUTO-SLAVEposition,
bothChannelsattenuatethesameamountwheneitheroneexceedsits
threshold.
8.POWERINDICATOR. IndicatesthepoweronconditionoftheFVL22.

REARPANELDESCRIPTION
1.AUDIOINPUTTERMINALS. Attachbalancedinputlinestothe“+”,“–”,and
SHIELDGROUND#6terminals.ToruntheFVL22unbalanced, attach the
positivelead tothe “+”terminal andleave the“–” terminalopen.
2.AUDIOOUTPUTTERMINALS. Attachbalancedoutputlinestothe“+”,“–”,
andSHIELDGROUND#6terminals.ToruntheFVL 22 unbalanced,attachthe
positivelead tothe “+”terminal andleave the“–” terminalopen.
3.PATCHI/OJACK provides aconvenient methodto usethe FVL22 asan
external processor for a mixer or other device with tip = send, ring = return insert
points.UseatwoconductorshieldedTip-Ring-Sleevecable.Use of thePATCHI/
Ojackautomaticallydisconnectstheterminalstripinput.
4.VOLTAGECONTROL. TheseterminalsareyourgatewaytotheVCAcontrol
circuitry.TheVREFterminalprovidesaprecise10VDCreferencevoltageoutput.
TheV1terminal acceptsa givenvoltage (+5 to24VDC), whichwhen properly
calibrated,providesmaximumattenuation.Asthisvoltagedecreases,theaudio
levelincreases.Decreasethisvoltagewithwhatevermethodsuitsyourapplica-
tion(Potentiometer,switch,orvoltageramp—seebackpagefordetails).
5.GROUNDLIFTSWITCH providestheabilitytoseparatechassisgroundand
signalground.Normally,thisswitchshouldbeintheLIFTposition.Insome
circumstancesitmaybenecessary to moveittotheoppositepositiontoeliminate
stubbornhumandbuzzproblems.SeetheCHASSISGROUNDINGnotebelow
fordetails.CAUTION: Ifyou are temptedto trymoving thisswitch with your
amplifierlevelsturnedup,don’tbe.Alwaysturnyouramplifierlevelsdown
beforechangingyourgroundsaroundandthenbringthemupslowly.
6.POWERINPUTCONNECTOR. Thisisthespotwherethe“appropriatepower
supply”connects.Again, foracompletedefinitionofthepowersupply,lookto
thefirstpage forinformationconcerningthesourcenearestyou.
7.GROUNDCONNECTOR. SincetheFVL22ispoweredfromaremoteAC
powersupplywhichdoesnotcarrychassisgroundthroughtothegroundingpin
of the AC cord, this 6-32 screw has been provided in case your system does not
haveanother earthgrounding meanssuch asthrough rack rails,etc. Itsuse or
disuseshouldbedeterminedbyyourspecificapplication.

All features & specifications subject to change without notice. 520-254 JUL95Printed in the U.S.A. on Recycled Paper
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OPERATINGINSTRUCTIONS
TheFVL22isatwo Channel VoltageControlledAmpli-
fier(VCA)providingthefollowingfunctions—anaudiolevel
control,andalimiter.
REMOTEAUDIOLEVELCONTROL
Applyingacontrol voltagetothe V1orV2 terminalssets
thegainthrough theunit.This voltageiscontrolled froma
remotepotentiometer,switchorramp.A 10 voltreferenceis
providedattheVREF terminaloryoumay provideyourown
5to 25 voltsource remotely.
Withzero volts appliedto V1 orV2, there is no attenua-
tion of the signal (unity gain). As the control voltage in-
creases,thesignalattenuates.Whenthemaximumcalibrated
controlvoltageisapplied,thereismaximumattenuationof
thesignal.
Tocalibratetheunit,applythemaximum voltage(an
unattenuatedpot,aclosedswitch,ormaximumvoltageramp)
toV1.AdjustthescrewdriverVOLTAGECALIBRATION
controluntilthe CALindicatorisilluminated.Thisallowsthe
maximumattenuationoverthecontrolvoltagerange.
Figures1-4showwiringdiagramstosuitmostapplica-
tions.
LIMITER
Thelimiterfunctionlimitsthemaximumoutputlevelof
theFVL22.Tosetthe limiter, rotatethescrewdriver-adjust
LIMITERcontrolfullycounterclockwise.Thenadvanceit
clockwisetothemaximumdBuoutputdesired.Notethatthis
controlhas twoscales, onefor balancedoperation and one for
balancedoperation. Be sure to use the proper scale for your
application.
Whenusedinconjunctionwiththeaudiolevelcontrol
featureabove,notethatthelimitertakes precedence.The
audiolevel can only be controlledwhen it isunder the
thresholdof the limiter (i.e. whenthe LIMIT indicatoris off).
Thelimiterhasanadditionalfeature—AUTO-SLAVE.
Thisswitch tiesthe control circuitry of thetwo limiters
together.IfeitherChannel’slevelexceedsitssetthreshold,
bothChannelslimitthesameamount.Thisretainsspectral
balanceforbi-ampedloudspeakersorpreservedstereoimage
instereoapplications.
Remember,Auto-Slaveonlyaffectsthelimiters,notthe
VCAs.
Figure1.RemotePotUsingFVL22Reference
Figure2.RemoteSwitchWithRemoteReference
Figure3.VoltageRamp(from+5to +24VDC)
Figure4.RemotePotWithRemoteReference
CHASSISGROUNDING
RaneFlex modules aresupplied with arear or side
mountedground-liftswitch.Theunitisshippedwiththis
switchinthe“grounded”position,tyingcircuitgroundto
chassisground.If afterhookingupyoursystemitexhibits
excessivehumorbuzzing,thereisanincompatibilityin
thegroundingconfigurationbetweenunitssomewhere.
Yourmission,shouldyouacceptit,istodiscoverhow
yourparticularsystemwantstobegrounded. Hereare
somethingsto try:
1.Trycombinations ofliftinggrounds onunits that are
suppliedwithgroundliftswitchesorlinks.
2. If your equipment is in a rack, verify that all chassis are
tiedto a good earth ground,either through theline cord
groundingpinortherackscrewsto anothergrounded
chassis.
3.UnitswithoutboardpowersuppliesdoNOTground
thechassisthroughthelinecord. Make surethatthese
unitsaregroundedeithertoanotherchassiswhichis
earthgrounded,ordirectlytothegrounding screwon
an AC outlet cover by means of a wire connected to a
screwon the chassis with a star washer to guarantee
propercontact.
Pleasereferto RaneNote110 (suppliedwith your unit
and available on request at no charge if you lose it) for
furtherinformationonsystemgrounding.
IMPORTANTNOTE