
Fender ’Champion “600”•Mercury Upgrade Kit 3
ThisprojectanditsdocumentationistheresultoftechnicalinvestigationsmadebytheengineeringstaffofMercury Magnetics.Thedisclosureoftheinformationhereinmaypertaintoproprietaryrightsand
thefurnishingofthesedocumentsdoesnotconstituteanexpresedorimpliedlicensetousesuchmaterials.
SOLDERING NOTE:YourampisassembledusingRoHScompliant,lead-freesolder.Workingwithlead-freesolderisdifferentthan
standardsolder.Generallyahotterironisnecessary.Formoreinformationwerecommenddoingaweb-earchfor“lead-
freesolderingtechniques.”
CAPACITOR DISCHARGE WARNING:Safedischargingofltercapacitorsmatters.Itisessentialforyoursafetyand
topreventdamagetotheamp’scircuitry,thatlargeorhighvoltagecapacitorsbefullydischargedbeforemeasurements
aremade,solderingisattempted,orthecircuitryistouchedinanyway.Forinformationonhowtodothis,web-search
“capacitordischarging.”Alsoseetheappendixforadditionalinformation.
CAPACITOR POLARITY:Notethatmanycapacitorshavepositiveandnegativepolarity,andarestampedaccordingly.
BesurethattheirpolarityiscorrectwhensolderingtoaPCB.
BRAIDING, TWISTING AND COILING LEADS:Donotbraid,twistorcoilthepowertransformer’sB+leadwire.Check
ourreferenceillustrationsandphotostoseewhichleadsaretwistedtogether.Typicallyonlythelamentleadsofthe
powertransformer.Otherpositioningofleadsmaybenecessarytominimizeampnoise.Followarediagramsand
instructsforoptimalperformance.
TRIMMING TRANSFORMER LEADS:Tominimizenoise,measureandtrimthesolderableleadlengthsofthetrans-
formersandMini-Choke™.Routeallwirescleaningaroundthetubes,chassis,etc.
CLIPPING vs. UNSOLDERING PCB COMPONENTS:TomakethisUpgradeitwillbenecessarytoremoveseveral
componentsfromtheMainPCBoftheamp.Duetoqualityissueswithmodernoff-shorePCBmanufacturing,itcan
bedifculttounsolderanitemwithoutcreatingotherproblems,themosttypicalofwhichisaneyeletdetachingfrom
thePCB.Thereforewe’veindicatedwhichcomponentsshouldbeclippedvs.unsoldered.Tounsolderheatyouriron
to800ºF,thenveryquicklyheatinguponesideoftheexistingsolderconnectionwhilepullingitthroughontheother.If
theironisnothotenough,oryoulingertoolong,theeyeletwillgetdamaged(orfalloff).Ifthishappensyou’llhaveto
fabricatearepair,orcreatedajumpertoatrace.Seethismanual’sappendicesfortips.
POWERING UP A GUITAR AMP:Aftermakinganymodicationstoanamp’scircuit(e.g.thisUpgrade)useaVariac
alongwithancurrentmeter(somehaveboth)toslowlyapplypowertotheampwhilecheckingforwarningsignsof
circuitryerrorsorshorts.Seethesectionon“UsingaVariac”attheendofthismanual.
LOADING OUTPUT TRANSFORMERS:Youmustconnectaspeakerorspeakercabtoyourampbeforepoweringit
up.Withoutaloadtheoutputtransformerwillblow.
MINI-CHOKE FACTOID:AMercuryMini-Choke™replacesaresistorandaddsadisernableamountoftonaldimen-
siontothecircuit.
TRANSFORMER BREAK IN PERIOD:Asageneralrule,transformersrequireapproximately30hoursofplaying time
tobefullybrokenin.PleaserefertoMercury’swebsiteformoreinformation.
BE SAFE! ALWAYS USE PROTECTIVE EYEWEAR!
Table of Contents
Referencephotosofstockamp......................................................................4
Partslist.........................................................................................5
MercuryUpgradewiringschematic...................................................................6
MercuryUpgradePCBlocationdiagram...............................................................7
Transformersandchokespecicationssheets.........................................................10
Transformerlocationsonthechassis.................................................................13
How-Toillustrations...............................................................................14
Appendices:
UsingaVariac................................................................................23
Tips’nTricks–WorkingonPCBs.................................................................26
TheOutputTransformerCircuit...................................................................28
DANGER!DischargingthoseFilterCaps!...........................................................29
CAUTION!Thevoltagesinyourampliercanbedangerous.Transformersandchokesarenotuserservicableparts.Installationof
thesecomponentsshouldalwaysbeperformedbyanexperiencedtechnician.Thesimpleabilitytouseasolderingironisnotenough
toqualifya“do-it-yourselfperson.”Thosewhoareinexperiencedinworkingwithelectroniccircuitsshouldneverattempttoservicetheir
ampliers.Householdlinecurrentscanbedeadly!!Transformers,chokesandlargeltercapacitorscanstoredangerouschargesfor
severaldays,orlonger,aftertheamplierhasbeenunplugged.Nevertouchtheterminalsofthesecomponentswithoutbeingcertain
oftheirchargestatus.Riskofshockanddamagetoequipmentmayresultfrommishandlingand/orimproperuseofthesecomponents.
Pleaseusecommonsenseandalwaysthinksafetyrst.Afterall,greattoneismostenjoyedwhenyouarealivetohearit.
Recommended tools for this project:
• Goodqualitysolderiron(capableoftempsat>800ºF)
• Electronicsgradesolder
• Soldersuckerand/orwick
• Dremel Toolwith1/16"bit,reamerandsmallgrinder*
• Setofscrewdrivers(Philips)
• ExactoknifeforcuttingandscrapingPCBtraces*
• Smallneedle-noseplyers
• Wirestrippers
• Loctite 290(green)
• PureisopropylalcoholandQ-tips
• Variacandcurrentmeter
*Dremel ToolcanbeusedtocuttracesanddrillholesinPCB.