Caledonian Audio 6BM8/ECL82 SE User manual

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Version!1.0!
Caledonian!Audio!
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Version!
Date!
Changes!
0.1!
1st!of!May!2018!
Initial!creation!
1.0!
1st!of!Nov!2018!
Reviewed!and!accepted!
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Caledonian!Audio!
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The! work! that! will! be! conducted! here! deals! with! high-level!voltages.! It! should!
only!be!conducted!by!:,*&9L9#M!personals.!
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Please!be!aware!that!N*O*N9?=<"!can!hold!charges!for!a!long!period!of!time!and!
they!should!be!properly!M9"NP*<Q#M!prior!to!touching!any!conductive!parts.!
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The! 6.3V! or! 12V! terminals! are!rated! in! relation! to! another! voltage! reference!
level,! but! in! reality,! the! potential! difference! between! the! 12V! (as! an! example)!
and! ground! earth! might! be! anywhere! up! to! 400V.! So,! please! treat! any! 6.3V! or!
12V!terminals!with!#R?<#$#!care.!
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Introduction!..........................................................................................................................................!6!
Assembly!Instructions!.................................................................................................................!7!
PCBs!Preparation!................................................................................................................................!8!
Heater!Filament!PCB!....................................................................................................................!8!
Main!Power!Supply!PCB!...........................................................................................................!10!
Amplifier!PCBs!..............................................................................................................................!17!
Mounting!Components!...................................................................................................................!19!
Wiring!....................................................................................................................................................!22!
Power!Cables!.................................................................................................................................!24!
B+!Power!Cables!......................................................................................................................!27!
Heater!Filament!Power!Cables!..........................................................................................!29!
Audio!cables!wiring!....................................................................................................................!31!
RCA!to!Potentiometer!...........................................................................................................!31!
Potentiometer!to!Amplifier!PCB!.......................................................................................!33!
Amplifier!Boards!Wiring!......................................................................................................!35!
Speaker!Output!Wiring!.........................................................................................................!37!
Assembly!Completion!.....................................................................................................................!39!
Powering!Up!For!The!First!Time!...............................................................................................!40!
Questions!/!Support!........................................................................................................................!42!
Appendix!..............................................................................................................................................!43!
I.! Amplifier!PCB!Components!.............................................................................................!43!
II.! Main!Power!Supply!PCB!Components!.......................................................................!43!
III.! Heater!Filament!PCB!.......................................................................................................!43!
IV.! Schematics!............................................................................................................................!44!
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Figure!1!–!Filament!supply!board!with!the!four!diodes!....................................................!8!
Figure!2!–!Filament!supply!board!now!populated!with!the!smoothing!capacitors!9!
Figure!3!–!Main!power!supply!PCB!with!C4!capacitor!and!the!bleeder!resistor,!R5
!........................................................................................................................................................!10!
Figure!4!–!Main!power!supply!PCB!with!two!diodes!........................................................!11!
Figure!5!–!Main!power!supply!PCB!with!all!diodes!installed!........................................!12!
Figure!6!–!Main!power!supply!PCB!with!all!radial!capacitors!......................................!13!
Figure!7!–!Main!power!supply!PCB!with!all!dropper!resistors!installed!..................!14!
Figure!8!-!Main!power!supply!PCB!fully!populated!...........................................................!15!
Figure!9!-!Main!power!supply!PCB!fully!populated!-!another!angle!...........................!16!
Figure!10!-!Amp!PCB!Side!B!fully!populated!.........................................................................!17!
Figure!11!-!Amp!PCB!Side!A!fully!populated!.........................................................................!18!
Figure!12!-!Placement!of!parts!on!the!mounting!plate!-!top!views!.............................!19!
Figure!13!-!the!complete!system!................................................................................................!20!
Figure!14!-!wiring!diagram!...........................................................................................................!23!
Figure!15!-!Ground!earth!from!IEC!socket!wired!to!the!chassis!and!secured!by!
shakeproof!washer!and!insert!lock!nut!.........................................................................!24!
Figure!16!-!Live!(brown)!and!neutral!(blue)!cables!connecting!the!main!power!
from!the!IEC!socket!to!the!power!switch!.....................................................................!25!
Figure!17!-!Live!(brown)!and!neutral!(blue)!cables!from!the!power!switch!
supplying!main!power!to!the!power!transformer!(0V,!240V)!............................!26!

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Figure!18!-!Two!cables!(brown)!connecting!power!transformer!secondary!
terminals!(250V!-!0)!to!the!main!power!supply!PCB!(AC!IN).!!The!
green/yellow!cable!is!the!ground!level!cable!connecting!the!0V!to!the!star!
ground.!Note!the!twisted!red!cables!carrying!B+!voltages!from!the!B+!
terminal!on!the!PCB!to!the!two!amplifier!boards.!....................................................!27!
Figure!19!-!Completed!main!power!supply!board!wiring!...............................................!28!
Figure!20!-!Twisted!red!cables!carrying!B+!voltage!into!the!two!amplifier!boards
!........................................................................................................................................................!28!
Figure!21!-!Two!cables!(red!and!black)!connecting!power!transformer!secondary!
terminals!(6.3V,!0V)!to!the!filament!power!supply!PCB!(AC!+/-!IN)!................!29!
Figure!22!-!Green!cable!connecting!the!0V!terminal!on!the!filament!power!supply!
PCB!and!the!star!ground!point.!The!black!sleeve!contains!four!wires!carrying!
the!6.3VDC!line!(two!positives!and!two!negatives)!from!the!filament!power!
supply!to!the!H1!and!H2!terminals!on!both!amplifier!boards.!The!polarity!on!
the!H1!and!H2!do!not!matter!at!all,!as!long!as!one!receives!a!positive!voltage!
and!the!other!receives!negative!voltage.!......................................................................!30!
Figure!23!-!Completed!wiring!for!filament!supply!PCB!...................................................!30!
Figure!24!-!RCA!to!potentiometer!connections!...................................................................!31!
Figure!25!-!Single!core!insulated!copper!wire!used!for!ground!connections!.........!32!
Figure!26!-!Potentiometer!wiring!..............................................................................................!33!
Figure!27!-!Potentiometer!wiring!-!another!angle!.............................................................!33!
Figure!28!-!Audio!input!cables!going!into!the!amplifier!board!.....................................!34!
Figure!29!-!Amplifier!Board!Wiring!..........................................................................................!36!
Figure!30!-!Amplifier!PCB!revisit!...............................................................................................!37!
Figure!31!-!connecting!the!output!transformer!to!speaker!terminals!......................!38!
Figure!32!-!Complete!wiring!and!components!assembly!................................................!39!
Figure!33!-!Schematics!...................................................................................................................!44!
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Introduction*
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Congratulations! and! thank! you!for! purchasing! on! this!kit.! This! guide! enables!
readers!to!build!and!assemble!the!6BM8/ECL82!SE!Classique!DIY!amp!kit.!The!
6BM8/ECL82!SE!is!a!pure!Class!A!Single!Ended!valve!amplifier!that!uses!a!two-
stage!amplification!single!valve!per!channel!topology.!
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Its!features!include:!
•2.5W!-!Pure!Class!A!per!channel!output!
•Single!ended!topology!
•Fast! Silicon! Carbide! Schottky! Diode! and! audio! grade! Electrolytic!
Capacitor!for!power!supply!producing!well!filtered!DC!power!
•DC!heater!filament!supply!
•Quality!electronic!components!
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If!you!have!any!questions!please!get!in!touch!with!us!at:!
[email protected].!!
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We! also! value! any! feedbacks! that! you! might! have! after! going! through! this!
document.!
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•Heater!filament!PCB!Version!A!
•Main!power!supply!PCB!Version!A!
•Amp!PCB!6BM8!PCB!Version!B!
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1. Only! parts! and! devices,! which! are! part! of! this!kit,!are! used.! Caledonian!
Audio!will!not!support!usage!of!any!other!parts!or!components!other!than!
supplied!and!mentioned!by!us!in!this!document!
2. The!supplied!mounting!board!is!used!
3. Reader!is!capable!of!performing!wiring!/!soldering!and!understands!risks!
of!fatal!level!of!voltages!!
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•Screwdrivers!(multiple!sizes)!
•Long!nose!pliers!
•Soldering!iron!(with!solders!etc.)!
•Wire!cutters!
•Wire!strippers!
•Cables!/!wires!for!hookups!and!power!lines!
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Assembly*Instructions*
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The!general!assembly!plan!is!as!follows:!!
1. Prepare!all!PCBs!
2. Mount!all!transformers!onto!mounting!board!
3. Mount!all!connectors!(power!and!audio)!
4. Mount!potentiometer!
5. Install!power!cables!
6. Install!audio!/!hookup!cables!
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PCBs*Preparation*
Heater*Filament*PCB*
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Place! and! solder! the!four!diodes!(D5,! D6,! D7! and! D8);! note! the! polarity! of! the!
diodes!(Figure!1!–!Filament!supply!board!with!the!four!diodes).!Use!the!marking!on!
the!PCB!as!a!guide.!!
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Place!and!solder!the!2!smoothing!capacitors!(Figure!2!–!Filament!supply!board!now!
populated! with! the! smoothing! capacitors).! Please! note! the! polarity! of! the! two!
capacitors.!The!PCB!is!now!complete.!
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Main*Power*Supply*PCB*
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Begin! by! placing! and! soldering! capacitor! C4! and! resistor!R5! (Figure! 3! –! Main!
power!supply!PCB!with!C4!capacitor!and!the!bleeder!resistor,!R5).!
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Now!place!and!solder!the!diodes!(D1!–!D4).!Please!note!the!polarity!(Figure!4!–!
Main!power!supply!PCB!with!two!diodes!and!Figure!5!–!Main!power!supply!PCB!with!all!
diodes!installed).!
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Now! place! and! solder! all!radial! capacitors.! Please! note! the! polarities! on! the!
capacitors.!(Figure!6!–!Main!power!supply!PCB!with!all!radial!capacitors).!
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Place!and!solder!the!dropper!resistors!(R1!–!R4).!!!!
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Figure!7!shows!the!resistors!placed!and!soldered.!The!main!power!supply!PCB!is!
now!ready.!!
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See! Figure! 8! -! Main! power! supply! PCB! fully! populated!and! Figure! 9! -! Main! power!
supply!PCB!fully!populated!-!another!angle!for! additional!images! of!the! completed!
PCB.!
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Amplifier*PCBs*
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There!are!two!amplifier!PCBs!included!in!the!kit,!one!for!each!channel.!Start!with!
one!of!them.!
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On! Side! B! of! the! amplifier! PCB! (note! the! B! side! marker),! place! and! solder! the!
valve/tube!socket.!Ensure!that!it!is!sitting!correctly!and!leveled!with!the!PCB.!It!
is! important! to! sit! the! socket! correctly! (the! axis! of! the! socket! and! PCB! are!
parallel)!as!this!will!determine!the!angle!of!the!valve!when!it!is!inserted.!!
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Place!and! solder!all! the! resistors.! Follow!the! labeling! on! the! board!against! the!
labels! of! the! resistors’! packaging.! It! is! highly! recommended! that! you! double!
check!the!resistor! value!using!a! digital!multimeter!against! the!labeling!as! well,!
just!in!case!there!has!been!error!in!the!manufacturing!process.!!
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Now!flip!the!PCB!over!to!Side!A.!!Place!and!solder!all!capacitors!as!labeled.!!
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Now!repeat!the!process!with!another!board.!!
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Mounting*Components*
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Install!the!following!on!the!supplied!mounting!board:!
1. IEC!socket!
2. Power!transformer!
3. Audio!transformers!(x2)!
4. All!PCBs!!
5. Speaker!terminals!!
6. Audio!input!terminals!
7. Potentiometer!
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Figure! 12!shows! the! location! of! the! parts! to! be! placed! and! secured! on! the!
mounting!plate.!Note!that!the!placement!diagram!is!a!view!from!the!top!of!the!
mounting!board.!
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Our!aim!for!now!is!to!produce!the!complete!system!as!per!Figure!13!-!the!complete!
system.!!
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All!fixings!are!included!in!the!kit.!Table!below!summarizes!the!sizes!of!the!fixings!
used!for!all!parts.!
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Output!transformer!
•Slot! Pan! Head! Machine! Screw!
Brass!Nickel!Plated,!M4,!20mm!
•RS! PRO,! M4,! Bright! Zinc! Plated!
Steel!Nylon!Insert!Lock!Nut!
•Bright! Zinc! Plated! Steel! Plain!
Washer,!0.8mm!Thickness,!M4!
Main!transformer!
•Included! in! the! transformer!
package!
Please! make! sure! that! the! core! of! the!
transformer! sits! flushed! on! the!
mounting! plate! (i.e.! no! washer! in!
between! the! mounting! plate! and! the!
body!of!the!transformer)!
PCBs!(all)!
•Slot! Pan! Head! Machine! Screw!
Brass!Nickel!Plated,!M3,!6mm!
•RS! PRO! Steel! Hex! Standoff!
Female/Female,! 20mm,! M3! x!