GOD CITY INSTRUMENTS Stockwell V1.1 User manual

God$City$Instruments$–$Stockwell$V1.1$Build$Guide$
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GOD$CITY$INSTRUMENTS$–$Stockwell$V1.1$Build$guide$
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The$God$City$Instruments$(GCI)$Stockwell$is$an$active$mid@range$EQ$Wien$bridge$topology$inspired$by$the$Boss$
MT@2’s$mid$control$and$provides$approximately$15db$of$boost$or$cut$sweepable$between$200$Hz$and$8$kHz.$$
Use$it$before$a$dirt$circuit$to$affect$its$timbre,$clarity,$and$harmonic$content$or$after$a$dirt$circuit$to$provide$a$
wide$range$of$equalization$possibilities$with$just$two$simple$controls.$$It$can$be$built$as$a$stand@alone$pedal$or$
used$as$a$mod$to$add$EQ$control$to$another$circuit.$$$
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This$pedal$is$an$easy$build,$but$this$guide$is$intended$for$people$who$have$some$experience$building$pedals.$$
Component$sourcing,$component$identification,$assembly$techniques,$wiring$stomp$switches,$etc.$is$not$
covered.$$The$GCI$Brutalist$Jr.$assembly$guide$has$helpful$information$for$less$experienced$builders.$$That$guide$
can$be$found$here:$
http://www.kurtballou.com/brutalistjr/$
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For$your$convenience,$complete$parts$kits$including$everything$you$need$except$the$PCB$can$be$purchased$
through$Small$Bear$Electronics.$$Be$wary$that$they$may$need$to$make$substitutions$for$work@alike$components$
which$may$or$may$not$influence$the$tone$of$the$pedal.$$Be$aware$that$transistors$may$have$been$substituted$
for$work@alikes$with$different$pinouts.$
http://[email protected]/kit@stockwell@v1@1@pcb@not@included/$
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Available$separately$is$the$GCI$3PDT$utility$PCB$for$PCB$pin$3PDT$footswitches.$$This$PCB$makes$footswitch$
wiring$quick$and$easy.$$Not$compatible$with$solder$lug$style$switches.$$$
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Don’t$forget$to$connect$the$ground$pad$of$the$PCB$to$the$ground$lug$of$the$input,$output,$and$DC$power$jacks!$
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Due$to$the$scope$of$this$project,$technical$support$is$not$available.$$However,$consider$joining$the$GCI$DIY$PCB$
Builders$group$on$Facebook$to$get$advice$from$and$share$your$work$with$other$builders.$$We$require$that$all$
group$members$agree$to$the$rules$before$being$accepted$into$the$group.$$$
https://www.facebook.com/groups/2454786551255317/$
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Component$values$for$the$PCB$as$well$as$some$alternate$values$are$listed$below.$$This$is$a$BOM$for$the$PCB$
only.$$Resistors$and$diodes$are$6.3mm$leg$spacing,$film$and$ceramic$capacitors$are$5.08mm$leg$spacing,$and$
electrolytic$capacitors$are$2.54mm$leg$spacing.$$I/O$jacks,$DC$jack,$switch,$enclosure,$and$knobs$are$not$listed.$$
The$schematic$and$a$drill$template$for$a$125B$(1590N1)$sized$enclosure$are$also$attached.$
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God$City$Instruments$–$Stockwell$V1.1$Build$Guide$
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Part
Value
Description
Substitute
Substitution Notes
C1
1u
Film cap
C2
0.1u
Film cap
22n-0.22u
Input cap
C3
1u
Film cap
C4
1u
Film cap
C5
100p
Ceramic cap
C6
0.22u
Film cap
C7
0.1u
Film cap
C8
0.1u
Film cap
C9
100u
Electrolytic cap
C10
100u
Electrolytic cap
D1
1n5818
Schottky diode
1n5817, 1n4001, bat41
Any suitable protection diode for 9v
LED
L1
3mm LED
R1
150k
1/4 watt resistor
100k-1M
Bigger increases input gain. Should be equal or greater than R2.
R2
100k
1/4 watt resistor
100k-470k
Sets input impedance and gain, along with R1
R3
2.2M
1/4 watt resistor
1M
Pull down resistor
R4
100k
1/4 watt resistor
R5
1k
1/4 watt resistor
R6
10k
1/4 watt resistor
R7
10k
1/4 watt resistor
R8
1M
1/4 watt resistor
R9
100R
1/4 watt resistor
R10
100R
1/4 watt resistor
R11
4.7k
1/4 watt resistor
R12
4.7k
1/4 watt resistor
R13
1k
1/4 watt resistor
R14
1k
1/4 watt resistor
CLR
4.7k
1/4 watt resistor
1k-10k
Current limiting resistor for LED.
IC1
TL071P
OP AMP
IC2
TL072
Dual OP AMP
TLE2072, LM833, NE5532, etc
Any pin-compatible dual op amp.
FREQ
B10K
16mm dual pot
MID
B10K
16mm potentiometer
S
PAD
Send to PCB
L+
PAD
LED+
L-
PAD
LED-
R
PAD
Return from PCB
V
PAD
9v in
G
PAD
Ground
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God$City$Instruments$–$Stockwell$V1.1$Build$Guide$
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God$City$Instruments$–$Stockwell$V1.1$Build$Guide$
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0.500
0.313
0.125
0
0.829
1.379
3.828
4.803
0 0.559 1.309 2.059 2.618
0.500
0.375
0 0.772 1.309 1.847 2.618
0
0.454
0.914