Mercury Epiphone Valve Junior - Identifying Amplifier Version; Basic Flavors and Versions

4 Epiphone Valve Jr.•Mercury Upgrade Kit
ThisprojectanditsdocumentationistheresultoftechnicalinvestigationsmadebytheengineeringstaffofMercury Magnetics.Thedisclosureoftheinformationhereinmaypertaintoproprietaryrightsand
thefurnishingofthesedocumentsdoesnotconstituteanexpresedorimpliedlicensetousesuchmaterials.
READ THIS FIRST! Identifying which verion of the amp you own.
Therearecurrentlyatleast3differentversionsoftheValve Junior’sPCB(printedcircuitboard)in
circulation.BeforeyoucanbegintheUpgradeyoumustidentifywhichversionyouhavesothatyoucan
usethecorrectUpgradeinstructionmanualandparts.Usethefollowingasaguide.
2 Basic Flavors and 3 Versions
TheValve Jr.comesin2avors:Headorcombo.
Bothampsarefundamentallythesame,usingthe
samecomponents.However,theoriginalVersion1
Valve Jrs.camewithasingle4ohmoutput,whereas
thelaterVersions2and3weregiven4,8and16
ohmoutputs.
Anothercluetodeterminingwhichversionyouhave
isthechassis.Examinethechassisphotosonthe
left.Noticethelocationofthetubesockets.
Also,Version1and2PCBsweregreen,
whereasversion3PCBsaredarkbrown
(almostblack).
OtherthanthecolorofthePCBs,
Versions2and3arenearlyidentical.
However,Epiphonedidchange
thevaluesofsomeoftheminor
componentsfromVersion2to
3(whichareindicatedinthe
illustrationsinthismanual).
Note:Thereare2tutorialson
theCD-ROM;onespecically
forVersion1andtheother(this
one)forVersions2and3PCBs.You’ll
needtousetheappropriatetutorialforthePCB
versionyouhave.
Valve Jr. Head
With4,8&16ohmoutputs
(Version2and3only).
Valve Jr. Combo
Version1,2andtheoriginal3sare4ohmoutput
only.NowallVersion3sare4,8and16ohm.
Stock Version 1
Chassis
Stock Version 2 & 3
Chassis
Note the relocation of
the tube sockets.