18 Epiphone Valve Jr.•Mercury Upgrade Kit
ThisprojectanditsdocumentationistheresultoftechnicalinvestigationsmadebytheengineeringstaffofMercury Magnetics.Thedisclosureoftheinformationhereinmaypertaintoproprietaryrightsand
thefurnishingofthesedocumentsdoesnotconstituteanexpresedorimpliedlicensetousesuchmaterials.
R
eadthethismanualBEFOREbeginningthe
Upgrade.Inthatwayyou’llbemoreawareof
what’srequiredandwhetherornotitiswithinyour
ability.Also,besuretoreadthroughthevarious
appendicesforhelpfulhintsandtips.Ifyouhave
anyquestions,pleasedonothesitatetocallushere
atMercury Magnetics!
OUTLINE
You’reabouttostripyourstockampandprepareitfor
theMercury Upgrade.It’sgoodpracticetoplaceall
ofthecomponentsyouremoveintoholdingcontainers
sotheyareeasytolocateandwon’tgetlost.Mostofthe
componentsyouarestrippingwillnotbeusedagain.But
holdontoeverythingfornowuntilyourUpgradedamp
isupandrunning.
Let’sgetstarted:
1. Unplugtheampfromthepowersource(AC).
2. Removeallchassisretainingscrewsfromtheback
andthetwoonthetopoftheamp.
3. Removethechassisfromtheamp–disconnectthe
twospeakerwiresrst.
4. Dischargethecapacitors.
5. RemovethefollowingfromtheMainPCB(printed
circuitboard):
a. Tubes
b. Transformerclips
c. UnboltthemainPCB.
d. Unclipand/orunsolderallotherdirectconnections
tothemainPCB.
e. Unboltandremovethestockoutputandpower
transformers
Special note:Thesolderusedintheseampsis
RoHScompliant–atermforanewindustrystandard
thatbasicallymeansthesolderislead-free.This
alsomeansthatyou’llneedtouseagoodquality
ironrunninghotterthantraditionalsoldermelting
temperatures(setitforabout800°F)–RoHS
compliantsoldermeltsathighertempsthanthe
originalsolderingalloysbutit’slikelyyou’llbeusing
regularelectronicssolderforthisproject.Youmayalso
wanttodoawebsearchtostudyuponworkingwith
RoHSsolder.
Fordrillingorresizingholeswerecommendthatyouuse
aDremel Toolwitha1/16"bit.Aholereamingbitwillalso
comeinhandytoenlargeexistingholes.Andasmall
grindingheadwillserveasatrace-cutter.Asharppocket
knifeorExactoisrecommendedforscrapingawayPCB
insulationtorevealtraces.
Seeappendixesforspecialinstructionsregardingtrace
cutting,tracerevealing,andaddingjumpers.
6. Usetheillustrationsasareferencetostripthemain
PCBinthisorder:
a. Unsolderitems
b. Holedrillingandenlarging
c. Cuttraces
d. Revealtraces
e. Addjumpers
7. Carefullycompareyourstrippedandmodied
MainPCBsothatitmatchestheillustrationsinthis
Sequence.Amissedstepormistakewillbiteyoulater
on.Takeyourtimetodoamethodicalandthorough
approach.
8. Thechassisneedstobemodiedtoholdthe
Upgradedpower andoutput transformerandthe
Mini-Choke.Ifyouwillbeaddingthe6V6 Mod,you’ll
needtoaddthetubesocketaswell.Referencethe
chassistemplate,makethemodicationsandbolton
thetransformersandMini-Choke.Ifyou’llbeaddingthe
6V6Mod,seethespecialsectionregardinghow.
VERSION 2 & 3 PCBs ONLY!
An Overview of the Upgrading Process