Stewart MacDonald bomb boost Assembly Instructions Manual Download Page 1

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©2017 Stewart-MacDonald 

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Sheet #i-2151  Updated 1/17

Assembly Instructions

The 

BOMB BOOST 

is a classic pedal created by JHS, 

makers of high-end effects pedals. Whenever JHS 
adds a new pedal to their line, they retire an existing  
design. This means great JHS pedals like the 

BOMB BOOST 

have become rare and sought-after. You can’t buy one, but 
you can build yourself one—and it’s fun!

This 

BOMB BOOST KIT

 is the perfect entry into build-

ing your own pedals: an easy project without many parts. 
If you’ve never assembled a pedal before, start right here! 

This pedal is a 16dB JFET boost that will push a tube amp into 
a clear, natural distortion. Use it in front of your overdrive, 
distortion, and fuzz pedals for a thicker, more saturated tone. 
Put it after your pedals to maintain your existing tone, but 
make it louder (perfect for solos). Or keep it on all the time 
to boost signal loss caused by long signal chains or by pedals 
that aren’t true bypass.

The original 

BOMB BOOST

 was a 

MINI 

version, housed in a 

mini-sized case. For this kit, we’ve resized the original circuit 
to fit a standard enclosure.

Easy instructio

ns!

Clear pictures sho

w where

each part goes

.

C L A S S I C   P E D A L   K I T

BOMB BOOST

StewMac

Summary of Contents for bomb boost

Page 1: ...without many parts If you ve never assembled a pedal before start right here Thispedalisa16dBJFETboostthatwillpushatubeampinto a clear natural distortion Use it in front of your overdrive distortion andfuzzpedalsforathicker moresaturatedtone Put it after your pedals to maintain your existing tone but make it louder perfect for solos Or keep it on all the time toboostsignallosscausedbylongsignalcha...

Page 2: ...nts in place for soldering by threading the leads through the board and bending them apart on the reverse side Makeyoursolderjointsonthereverseside Insertthetipinto the eyelet and let it heat for 4 5 seconds before touching it with solder This heats the contact enough for the solder to flow nicely without damage You don t need much solder just enough to fill the eyelet After soldering trim away th...

Page 3: ...Transistor J201 7318 1 Ribbon cable 2 6 Lead wires 2 7460 1 DC power connector 21MM 1611 1 Footswitch 3PDT latching 7360 1 R1 Resistor 5 1 kΩ 7365 1 R2 Resistor 100 kΩ 7351 1 R3 Resistor 47 Ω 7357 1 R4 Resistor 1 kΩ 7402 1 D1 Diode P6KE12A 7311 1 C1 Capacitor 22 µF 7560 4 Adhesive foam tape 7456 1 Volume pot 1 MΩ linear taper 4652 2 Mono jacks 1 4 7551 1 Metal case with 4 screws 1 Circuit board 75...

Page 4: ...sistors are not polarized so it doesn t matter which lead goes in which eyelet They can be installed in either direction Diodes are polarized so they need to be installed in the correct orientation Note the stripe around one end this marks the negative minus lead of the diode On the circuit board the printed outline of the diodes also shows this stripe Install each diode so that its stripe matches...

Page 5: ...ripe running the length of the cap identifying the negative minus lead On the circuit board the circle for this cap s location has a thicker line on one side insert C1 with its stripe facing that side On polarized caps of this type there s a second way to identify the minus lead it is the shorter of the two leads Solder cap C1 in place C2 is a 1 µF cap that is not polarized Solder it in place faci...

Page 6: ...t the pedal case Needle nose pliers work well for removing the pin Use the adhesive foam tape to insulate the back of the pot from the sol dered leads of the other parts Solder the pot in place making sure it sits flat on the back of the board Install the footswitch on the back of the circuit board The switch lugs will fit in only one of two directions either orientation works fine Insert the lugs...

Page 7: ...rd away from the main board Small wire cutters make quick work of this and a small saw also works LED mounting bezel Two jacks Install the plastic mounting bezel for the LED indicator by pressing it in from the outside through the top of the case Spread the tabs open inside the case to hold it in place Install the input and output jacks on the sides of the case Keep the lugs facing up so you ll ha...

Page 8: ...some of the caps and diodes the D8 LED Light Emitting Diode is polarized and has to be installed in a specific direction One side of the diode has a flat edge indicating the negative lead Another indication is that the negative lead is shorter than the positive The circle marking the D8 location on the switch circuit board has a corresponding flat to indicate the mounting orientation Insert the LE...

Page 9: ... Carefully install the switch so the legs of the diode feed through the D8holes on the switch circuit board Place the flat washer on the switchshaftonthe topofthe case As you tighten the remaining nut on the switch hold the switch circuit board inside the case so that it doesn t rotate Solder the D8 LED and trim the leads 1 8 Insert the DCpowerconnector so the negative lug is facing up and tighten...

Page 10: ... InJ S T S T R4 R3 R1 R2 D1 OutJ P78869 R4 1J63 D8 Onthecircuitboard theinputandoutputjackleadsarelabeledInJandOutJ The leads are also labeled T for tip and S for sleeve Looking at a jack you ll see that the sleeve lug is attached to the threaded shaft The tip lug connects to the spring metal piece that contacts the tip of a guitar cord Solder these four leads as shown to finish the assembly Screw...

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