Lightning Boy Audio Op-2 Comp User manual

Op-2%Comp%
By#Lightning Boy Audio#
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Rev.%B.1%User’s%Guide%(11/2018)%
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Congratulations#on#your#purchase#of#this#exquisite#piece#of#hand#crafted#vacuum#tube#technology#
from#Lightning#Boy#Audio!##It#was#my#great#pleasure#building#it#for#you.##Please#carefully#read#this#
guide#before#using#your#new#compressor#pedal.#
#
GETTING#STARTED:#
Included#is#a#24V#DC#power#adapter,#which#you#should#definitely#use.##The#Op-2#Comp#revision#B#
requires#24v#DC#at#170mA#(minimum#amperage#required#for#normal#operation).##It#will#not#work#
with#less#voltage#and#could#damage#the#tubes#if#the#voltage#is#exceeded.###The#tip/center#is#wired#
positive,#which#is#not#standard#for#most#FX#pedals#on#the#market.###
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Powering#up:##The#pedal#will#turn#on#as#soon#as#a#power#supply#is#connected.##Blue#LED#under#lights#
will#illuminate#the#vacuum#tubes#to#indicate#power-on#status.##The#vacuum#tubes#need#to#warm#up#
before#they#will#transmit#any#signal.##It#may#take#about#10#seconds#before#you#will#hear#anything.##It#
may#take#several#minutes#after#initial#power#up#for#the#pedal#to#sound#its#best.##To#ensure#long#life#of#
the#vacuum#tubes#it#is#advised#to#turn#off#or#unplug#your#power#supply#when#not#in#use.###
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Controls:##The#active/bypass%stomp%switch#is#true#bypass.##When#the#Lightning#Boy#logo#lights#up,#
the#pedal#is#activated.##When#the#logo#light#turns#off,#the#pedal#is#bypassed.##Next,#there#are#two#
(update:#3)#controls#for#the#compression.#The#compression%knob#is#simple#to#understand.##It’s#
basically#a#blend#control.##Turning#this#knob#clockwise#will#give#you#more#compression.##Fully#
clockwise#is#obviously#max#compression.##When#the#knob#is#fully#counter#clockwise#your#signal#will#
path#through#the#audio#tube#with#no#compression#occurring.##The#other#control#is#the#“Knee”%switch.##
This#toggles#between#a#soft#knee#compression#slope#in#the#downward#position#(towards#the#foot#
switch)#and#hard#knee#compression#slope#in#the#upward#position.##The#sonic#effects#of#each#can#be#
more#easily#heard#with#the#compression#knob#turned#all#the#way#up.##Basically,#hard#knee#is#a#more#
aggressive/snappy#sounding#compression#and#soft#knee#is#a#more#musical/smooth#sound.##The#
volume%knob#should#be#pretty#self-explanatory.##It#can#take#you#from#zero#to#a#significant#boost.##
Finally,#there#is#a#toggle#switch#located#to#the#left#of#the#vacuum#tubes.##This#is#the#“Turbo”%switch.##
(Update:##now#“Ratio”#switch).##The#new#update#makes#“Turbo”#always#on,#since#practically#everyone#
prefers#it#on.##What#was#the#turbo#switch#is#now#a#ratio#switch.##After#my#inventory#of#pedal#cases#run#
out,#which#could#be#a#while,#I’ll#start#labeling#this#switch#as#Limit/Compress.##So,#in#the#up#position#
where#it#was#“turbo,”#the#pedal#now#operates#in#limiter#mode.##The#down#position#is#compressor#
mode,#which#is#more#like#what#the#pedal#used#to#only#do.##This#new#limiter#mode#is#a#pretty#cool#
development,#which#I#will#explain#more#at#the#tail#end#of#this#guide.########
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Tubes:##Op-2#Comp#requires#two#12AU7#type#vacuum#tubes,#which#are#supplied#with#the#pedal.##One#
tube#is#directly#responsible#for#audio#amplification.##This#tube#is#the#one#directly#in#line#with#the#input#
jack.##The#other#tube#is#responsible#for#limiting#and#for#driving#the#optical#attenuator#circuitry.##That’s#
the#tube#in#line#with#the#output#jack.##The#Op-2#Comp#has#been#specifically#designed#around#the#
12AU7.##It#will#be#very#difficult#to#remove#the#stock#tubes#because#of#the#intense#gripping#strength#of#
the#high#quality#tube#sockets#used#in#the#pedal.##Taking#tubes#out#and#putting#in#new#tubes#requires#
delicate#care#to#not#damage#the#internal#wiring.##If#a#tube#replacement#is#needed#it#is#recommended#
that#you#return#the#pedal#to#Lightning#Boy#Audio#for#servicing.##If#you#want#to#perform#this#work#on#
your#own#or#by#a#tech#please#follow#the#succeeding#guidelines.##If#you#damage#the#pedal#performing#
this#work,#you#will#in#effect#void#the#warranty#of#the#pedal.###
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Replacing#vacuum#tubes:##This#is#not#recommended.##If#you#must,#the#first#step#is#to#make#sure#the#
pedal#is#unplugged.##Remove#tube#dampers#if#installed.##Then,#get#a#firm#grip#on#the#tube#to#be#

replaced.##Pull#with#force#while#slightly#wiggling#the#tube#back#and#forth.##DO#NOT#get#wild#with#the#
wiggle.##You#do#not#want#to#damage#the#internal#wiring.##By#taking#off#the#back#cover#you#will#see#
what#you’re#up#against.##Take#your#time.##It#can#take#several#minutes#to#unseat#the#tube.##To#install#the#
new#tube#you#will#now#need#to#remove#the#back#cover.##Place#a#finger#on#the#back#of#the#tube#socket,#
directly#on#the#LED#backlight#to#provide#support.##Inserting#the#new#tube#will#require#some#strength#
to#overcome#the#tight#socket.##Be#VERY#CAREFUL#to#make#sure#the#pins#are#lined#up#with#the#socket.##
After#you#have#seated#the#tube#on#the#socket,#you#can#peek#through#underneath#from#the#backside#to#
confirm#the#tube#is#fully#seated#on#the#socket.##Replace#the#cover,#plug#in,#rock!###
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TROUBLE#SHOOTING:#
•Pedal#has#become#excessively#noisy.##First#consider#replacing#the#tubes.##If#this#doesn’t#fix#it,#
try#a#new#power#adapter.##If#that#still#doesn’t#work,#send#it#back#to#LBA#for#repair.###
•Broken#tube.##Tricky#business#to#replace,#my#friend.##I#usually#pop#off#the#back#cover#and#
using#a#long,#finely#spiked#tool#(much#like#a#dentists#tool)#I#pry#the#tube#base#away#from#the#
socket#a#little,#then#rotate#and#repeat#until#the#tube#comes#free#from#the#socket.##If#you#do#not#
have#similar#tools#you#may#want#to#send#the#pedal#back#to#LBA#for#a#retube.###
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For#tube#replacements#and/or#servicing#please#contact#lightning#boy#audio#by#email#at#
[e-mail]#or#by#phone#at#1+716-472-6739.###
More#information#about#the#Op-2#Comp#can#be#found#on#its#product#page#at#
www.lightningboyaudio.com.##
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UPDATE%REV%B.1%designer%notes:%
This#new#limiter#mode#might#be#a#unique#approach#to#limiting.###The#compression#tube#is#a#
12AU7#dual#triode…#basically,#two#vacuum#tube#triodes#in#one#glass#envelope.##One#triode#drives#the#
optical#attenuator#electronics,#which#have#within#them#a#section#that#determines#a#prefixed#
threshold.##That#same#triode#also#drives#the#compression#indicator#light.##Now#here’s#where#it#gets#
real#interesting.##That#same#triode#just#mentioned#comes#last#in#the#chain#of#events.##Feeding#it#is#
another#triode,#which#boosts#the#signal#enough#to#cross#the#threshold.##When#engaging#limiter#mode#
it#forces#this#triode#to#boost#the#signal#so#much#it#saturates#the#triode,#basically#clipping#the#signal#
(tube#distortion).##You#then#have#a#clipped#and#boosted#signal#feeding#into#the#optical#attenuator#
driver.##That#is#to#say#more#of#your#signal#will#cross#the#threshold#and#the#ratio#will#be#more#extreme.##
So,#when#in#limiter#mode#there#are#actually#two#layers#of#compression#occurring.##One#directly#from#
the#optical#attenuator#and#one#indirectly#from#true#vacuum#tube#compression.###
Now#for#some#less#interesting#stuff.##What#was#the#power#indicator#light,#is#now#the#
compression#indicator#light.##Located#between#the#tubes#is#a#red#LED.##This#light#will#illuminate#when#
your#signal#crosses#the#threshold.##The#light#will#be#more#intense#when#compressing#more.##The#
compression#knob#has#no#effect#on#the#light#(or#visa#versa)#because#the#knob#is#actually#a#blend#knob.##
In#the#future#when#I#do#another#pedal#case#run#I’ll#print#“Blend”#on#the#cases#instead#of#compression.#
Lastly,#the#design#used#to#use#both#tubes#for#audio#amplification#and#tapped#off#some#of#the#
gain#to#drive#the#optical#section.##Not#so#with#the#new#configuration.##There#is#a#dedicated#audio#tube#
and#a#dedicated#compression#tube.##Changing#the#audio#tube#for#different#brands#may#result#in#tonal#
changes.##It’s#recommended#to#stick#with#12AU7/ECC82#tubes#if#you#want#to#try#this.##I’ll#include#a#
NOS#tube#for#the#audio#tube#for#as#long#as#the#market#price#is#reasonable.##For#the#compression#tube,#
it#matters#much#less#what#brand#is#involved,#so#I#installed#a#current#production#tube#in#this#position.##
HINT:##not#all#12AU7#tubes#create#the#exact#same#amount#of#gain.##There#is#variation#even#within#the#
same#brand.##I#select#high#gain#12AU7#tubes#for#this#pedal.###
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-Mike#