The Beginner Boost

From Breadboard To Box

© 2015 By Small Bear Electronics LLC

In the introductory article, I showed how to set up Gus Smalley's Beginner Boost V. 2 with tone stack on a solderless breadboard. Now we will commit to a soldered build on perfboard and house the effect in a gig-worthy enclosure. If you bought one of the breadboarding kits, the parts can be re-used if you wish. The result will be a professionally-useful pedal with all of the features that you would expect of a commercially-manufactured "boutique" design.

As I have done with some of my other "Breadboard-To-Box" projects, I will describe some of the electronic and mechanical considerations that went into developing the finished design. If you are new to building pedals, you'll learn some good construction habits and patterns of thinking and planning that will be helpful in building more complex designs.

I'll show two possible builds: The generic build on the right uses a standard 125-B enclosure that is available from many sources. On the left is a "deluxe" build in the made-for-Small Bear Bare Box #1. That one uses a number of made-to-order parts and specific modular connectors to produce a result that is comparable to a manufactured product. The sloped design reduces greatly the risk of stomped pots, and it includes a battery door. The difficulty levels of both builds are about the same, and  complete kits are available to take you either way.

  

Breadboard To Box - What Is Involved?

If you followed the breadboard build to its end, you have a working circuit, complete from input to output, like Figure 1.

Clearly, a number of elements need to be added to make this into a buildable design for a finished pedal. The most important is bypass switching, to allow the effect to be foot-switched in and out. There are numerous schemes for doing this, and I chose one that's known to work well and uses components that can be found almost anywhere.

  

3PDT True-Bypass Switching With In-Use LED Driver - How It Works

Here's a bottom view of a typical 3PDT (Three-pole, Double-throw) footswitch. It has nine contacts, and they work as shown in the schem in Figure 2. Push/release once and the moving contacts (2, 5 and 8) connect to #3, #6 and #9. Push/release again and they go back. We call this a "latching" or "alternate-action" switch, because the contacts remain in their new positions when you release the switch.

  
Let's add this to the schematic, trace through the connections and see how the switching works in practice.

In Figure 3, the effect is bypassed. The guitar input goes from the moving contact, pin 2, through stationary contacts pin 1 and pin 4 (which are connected with a jumper) to moving contact pin 5 and then to the output jack When the switch is stomped, the input jack sees the effect input through pin 3, and the output jack sees the tone control through pin 6. Two contacts of the third pole switch the LED on and off. OK so far? If you still have the circuit on your breadboard and want to set up the bypass to see/hear it work, by all means do so.

Answer to a FAQ: There are other ways to wire a stomp switch, with and without an in-use LED. They will all work, though some may be more suitable than others in a particular design situation. If you want more information, check the Beginner FAQ or other on-line sources.

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Power - Internal and External

While we were on the breadboard, we switched power off by disconnecting the battery. That won't work in a pedal, so we have to make some arrangements. And there are several issues:

  • We want a DC power jack, and we want the battery to be cut off when an external power supply is plugged in.



  • We want the circuit to be protected from reverse connection of power.



  • We want battery power to be cut off when the guitar plug is removed from the input jack.

Most modern pedals accomplish all of this in the same ways. External power comes in through a jack like the one of the ones in Fig. 4. These styles are designed to be mounted on the panel of an enclosure, while others mount on a circuit board. They all work similarly, as shown in the small schematic (Fig. 5). Contact #1 connects to the shell of the power plug, which will be positive in the typical negative-ground pedal design. Contact #3 forms a normally-closed switch with contact #1; it shorts to #1 until a power plug is inserted. Contact #2 is the center pin, which will be ground in this configuration.

  

Switching the battery off when the guitar is unplugged is done by using a stereo jack for the input. Since the Ring contact of such a jack is shorted to ground through the sleeve of a guitar plug, it provides a cheap and easy way to implement a necessary function. Do take a look at the physical jack and work out for yourself what is happening if you need to. Figure 5 shows the whole idea in schematic form.

Diode D1 takes care of reverse polarity protection; it will block current flow if the battery or power supply is connected incorrectly.

  

Here is the whole, buildable schem, including all of the support circuitry.

 
The "Bare Bones" Of Planning A Build
When working out a design, the first job is to translate the schematic to a suitable layout on a chassis or circuit board. You may notice that the layouts of many "Build Your Own Pedal" articles are pretty ad-hoc and haphazard. I organize my builds by following a rule that I worked out from listening to some of the engineers on the Forum, especially R. G. Keen: "Pick a suitable enclosure, then figure out where the off-board components will go, and then lay out the board so that the connections to the off-board components are as direct as possible."

I know that this will be a two-knob build, so I will want terminations for:

  • Two potentiometers
  • DC Power
  • Input from guitar
  • Output to amp
  • Stomp Switch
  • In-Use LED

I've already chosen a rectangular enclosure, oriented vertically like a typical off-the-shelf pedal. Putting the input jack on the right has become an industry standard, the stomp switch logically goes at the bottom and the power jack and pots at the top. Where the LED goes is a matter of taste; I usually locate it on the top left side.

This defines the basic layout of the enclosure, and we can now think about laying out the circuit board. When looking at the top of the case, the board inside actually sits component-side down, right?. So, turning the case over gives our first look at where the off-board terminations will be (Fig. 8).

FAQ: Which Material? Pad-Per-Hole vs. Veroboard

You will see many designs laid out on stripboard, also called Veroboard, or just Vero (Fig. 9). While I stock it because it's very popular, I don't recommend it for first builds. It's very convenient to use, but it does not force you to follow the logic of a schematic and wire point-to-point.  To my mind, that's an essential skill that a beginner needs to develop.

I recommend perforated circuit board, or perfboard as it is commonly called (Fig. 10).  Each hole on the bottom of the board is surrounded by a tinned copper pad to which solder can bond. This type of stock is called, appropriately, pad-per-hole perfboard. Component leads are inserted through the holes and soldered in place on the opposite side. Connections are made with short lengths of bare wire.

Tools and Materials

Some DIY builds are entirely paint-by-number, which I don't like--they don't teach much. Both builds in this article include some hand tooling. Before you begin creating the board, let's make sure that you have all the tools required. You'll need a few basics:

  • 25- to 35-watt soldering iron, rosin-core solder and cleaning sponge
  • Small screwdriver(s)
  • Small chain-nose pliers and side-cutters
  • Small locking-grip ("Vise-grip") plier
  • X-acto or similar knife
  • Self-locking tweezers or other "third hand"
  • Small alligator clip
  • Colored pencil or "Hi-liter" felt-tip marker
  • Some small round and flat files
  • A pointed steel "pick" or scratch awl
  • De-soldering braid

If you buy one of my kits, case is pre-drilled. If you are rolling-your-own, be prepared to borrow a drill if you don't have one.

For finishing the case you'll need:

  • 220-grit and 400- (or finer) grit carborundum paper
  • Acetone, denatured alcohol
  • Spray primer and enamel
  • Decal stock or decals
  • Clear lacquer like Krylon

These tools, and many others, are available in my Stock List.
First Job - Tool The Perfboard
Here is how to tool the 60 x 60 board for both the generic and the Bare Box builds. However, the methods are similar if you are using locally purchased material of any larger size. The drawings below (Figure 11) show what we need to wind up with.

For the generic build, the 60 x 60 needs to be cut down to 14 rows and two mounting holes must be added. If you don't have a Dremel tool, use a knife and a steel rule to score the board in the 15th row all the way across (Figure 12). Score a dozen or so times in order to deepen the line. If you have a vise or have access to one, clamp the piece in the jaws on the score line. Wedging the piece in a door frame will also work (Figure 13). Apply steady pressure on the edge until you feel the material snap. Borrow a drill if necessary to create two new 1/8" mounting holes (Figure 14).

If you have a Dremel tool and an abrasive cutoff wheel, this combination is by far the easiest way to work perfboard. However, if you go this route, be aware that the dust that the operation throws off contains fiberglass. WEAR GLOVES, GOGGLES AND A FACE MASK!
The 60 x 60 is exactly sized for the Bare Box, but it needs four cutouts to pass wiring from the off-board components. The coordinates are shown in figure 15. Using a knife, mark the outlines of the areas that need to be cut away (Fig. 16).

 
If you are limited to manual tools, continue using the knife and score each line that you have marked a dozen times. Then use pliers to bend and snap on the score lines, "nibbling" a little at a time (Fig. 17). Clean up the edges with a flat file (Fig. 18) and you should wind up with a piece that looks like figure 19.
Short Answer To An FAQ: How Do You Get To A Workable Component Layout?
The long answer really needs another tutorial by someone who has designed boards for a living, like R. G. Keen. In his case, he wrote a book. Short answer: We know where the off-board connections will be, so figuring out exactly where each component will go needs a lot of place-and-try. I see many attempts to use pencil-and-paper for this process, and I always advise against it; there are numerous software packages--some free to download--that make laying out a board both a lot easier and fun. Like all programs, they have a learning curve. But if you invest the time, you'll be amazed at what you can do going forward. I use DIY Layout Creator, which can be downloaded from a link on the Forum.

If you are building in the Bare Box, continue in the next section. For the generic build continue below.
Stuffing The Board For The Bare Box

Below is the board layout and a re-cap of the parts list. You are seeing the board in "X-Ray" view; the red lines are connections that we will make with bare wire on the bottom of the board. Print a copy of this drawing and the schematic so that you can mark off connections with a highlighter as you work. This is one of my time-tested methods for catching mistakes before they cost me time and frustration.
R1 4.7 Meg
R2 1K
R3 120K
R4, R5, R8, R10 47K
R6 10K
C1 100 mf.
C2, C6, C7 .01 mf.
C3 .47 mf.
C4 22 mf.
C5 1 mf.
Q1 2N2222A or similar
D1 1N5818
 

We are ready to populate ("stuff") the board. While components can be added in any order, I'm going to suggest that you start by installing the Molex headers for power, signals, switching and the pots. With those in place, you'll have good physical reference points for installing all of the other parts. Please note that I don't cover basic soldering techniques in this article; you may want to check a reference and do some practicing if this is your first build.

Find one of the two-pin horizontal Molex headers (Fig. 21). Install with its pins in indexes K-6 and L-6, use self-locking tweezers to hold it and solder in place (Fig. 22).

In the same way, locate, install and solder in place the other horizontal Molex headers: three-pin for the input, two-pin for the output and six-pin for the stomp switch. Follow with the two three-pin vertical headers for the potentiometers (Fig. 23, Fig. 24). Align the vertical headers as shown in the pic with their chamfered sides to the left.

We are ready to add components.
 Install the 100 mf. electrolytic capacitor (Fig. 25) with its positive side in index F-2. Solder in place and trim leads on the bottom (Fig. 26). Save those scraps of bare wire for later use in making connections!
Keep adding components, working up-and down and left to right. Capacitor C3 may span three,  four or five holes depending on the make, so form its leads accordingly. Observe polarity for the electrolytic capacitors C4 and C5. While silicon transistors and diodes are not as heat-sensitive as their germanium counterparts, it is a good idea to use an alligator clip as a heat sink, putting it on each lead of the device before soldering as in figure 27. Figure 28 shows the board fully populated except for the LED. That goes in last, during final assembly.

When planning a board layout for manufacture as a printed circuit board, jumpers are sometimes a way to avoid the expense of a double-sided PCB. The two jumpers on the component side are shown as  thin blue lines in the layout drawing. They can be formed from the scraps of wire that you trimmed from the other components, or you can use the tinned bare copper wire in the kit. Form a jumper that spans seven holes, install in indexes M-18 through S-18, and solder in place. The second jumper connects indices Q-14 and Q-16. Figure 29 shows both jumpers in place.

Wiring The Board

Now for the plumbing! With all the components in place, we begin to make connections between them with short lengths of bare tinned wire. First we'll do a long one: from the negative power input to the Ring of the input jack J2. As shown in figure 30, butt a length of bare wire up to index K-6. Use the locking tweezers to hold it in place and solder at K-5/K-6. Now use a chain-nose plier to put a right-angle bend in the wire. Make this as sharp as you can, and centered in column I.

"Tack" this part of the run with a little bit of solder at index I-1, bend downward in column C and tack again at index C-1. Bend clear of the mounting hole to get over to column A Bend downward, right-angle bend again at A-11 and tack at B-11. 45 degree bend at D-11 and end at G-12 (Fig.31).

If you want your best shot at having the build work right off the rip and you have a multimeter, use the continuity function every time you solder a connection to make sure that the points you think are connected Really Are. The terminals of the connectors Are accessible from the top of the board (Fig. 32).

.
Now try the ground run that starts at the negative side of electrolytic capacitor C1. Put a very short right-angle bend in the end of a length of bare wire (Fig. 33).  Insert the end into the hole at index D-2. Hold this in place with soldering tweezers (Fig. 34) and solder to join with the negative side of the capacitor at pad E-2. Cut the wire just short of the pad for the potentiometer connector at index D-5 and solder to join (Fig. 35).

Butt the remaining bare wire against the joint that you just made at index D-5, hold in place with soldering tweezers and solder (Fig. 36).

 
Create a right-angle bend down in column 2 and another in row 8. Cut at the negative side of electrolytic capacitor C4, index C-8. Hold the wire down with the tweezers and solder (Fig. 37).

Before continuing the run, I used the tip of my soldering iron to remove the pads at indices G-8 and F-9. It's a way to avoid problems where I think there might be a danger of a short between connections. Then I set up a short right-angle bend, installed that in index B-9 and soldered to join to B-8. This starts the rest of the ground run as shown in Figure 38. Note that it continues after the long jumper and ends up at R10. When finished, it is very important to test continuity all along the run and from beginning to end (Fig. 39).
Make the connection between L-5, the positive power input, and H-6, the positive side of diode D1. Follow with the run that connects F-2 (the positive side of capacitor C1), H-9, (the cathode of diode D1), resistor R3 and resistor R6 (Fig. 40).

I am a big fan of using the capacitance scale found on many multimeters to test continuity where a capacitor contacts a run on the board. Look at the layout for a second: The positive side of C1 contacts three points that are accessible on the component side, and its negative side is grounded. So we should see the value of the capacitor between any of those points and any point on the ground bus, right? And so we do, as in figure 41. (The capacitor is nominally 100 mf., but tolerance is typically 20%, so this is in range). Used consistently, this technique will smoke out numerous joints that are not quite connected.
If you are with me so far, you have the basics of the technique. Here is a table of the rest of the connections in the order I did them, with some notes where appropriate. With a highlighter, mark off connections on the layout as you make them.
E-5 to D-8 This is another good one to test for continuity through capacitor C4.
F-5 to J-12 to J-15
M-10 to M-12 to N-13, then join M-12 to P-12 With this done, you should see C3 (.47 mf.) from F-5 to any of the joined indices.
G-14 to O-19 (J4 contact #1). This is the input from the guitar. It's a long run, and it's OK to do it in sections.
G-18 to F-20
I-20 to L-18 to P-19 This is the input to the effect. Test continuity from the switch connector pin to resistors R1 and R2.
I-18 to K-16 to N-16
L-15 to P-11. Follow with P-11 to O-8.  
L-8 to P-1
Q-19 to S-15 Output jack tip. Test continuity between the header contacts.
R-19 to Q-16. Follow with Q-14 to R-5. Test from the switch connector pin to the center pin of the tone pot connector.
P-10 to R-10 to R-8
P-8 to Q-5 to P-3 Do the run from P-8 to P-3 and just flow solder to join the socket pin at Q-5.
U-10 to T-7 to S-5
T-19 to W-4. Follow with S-1 to U-3 Connections for the LED

The last step is actually installing the LED. For reasons you'll see later, I leave this until after the board is tested and we know that the effect works. Now, we can prepare the off-board components to connect to the board and then do an initial test (!).

Assembling The Pots, Jacks and Switch

If you bought the breadboard kit and are re-using parts, unsolder the connecting wires from the potentiometer terminals. I will presume here that you are using my modular approach to making the connections, so find six terminated leads and two male three-pin Molex housings (Fig. 42). Reserve the red and black leads for power. Other than that, it's your choice for which color goes where.

Install each lead into its hole in the housing. The terminal has a flange on one side, and you will feel it click into place when it is fully inserted (Fig. 43). Cut the leads down to about 2", strip, and solder as shown to create the potentiometer assemblies shown in figure 44. Take special care to get each pot on the proper side and the terminal assignments correct.

In the same way that you created the connectors for the pots, install black and red leads to set up a connector for power (Fig. 45).

 
Find a two-pin and a three-pin Molex plug. Assemble the connectors for input and output, using black leads where shown in figure 46. While the other leads can be any color, you may want to follow my example to avoid confusion.

The Bare Box #1 enclosure is tooled to be friendly to shrouded jacks like those used in many "name" pedals. These have a chamfer (bevel) on the sleeve pin edge, which is helpful for identifying the contacts. Start by locating the sleeve contact of the input jack and soldering the black center lead of the plug to this contact. The sleeve contact is the one on the beveled edge (“chamfer”) of the jack. For ease of assembly later, it’s best if the lead enters from the bottom of the contact and is bent at right-angles as shown before soldering (Fig.47).
The last piece of pre-assembly before you put everything together is creating the connector for the stomp switch and soldering those components together.Find the six-position Molex connector and the terminated leads for it, and assemble this as you did the others. While there is no standard for which color goes in which position, you may want to follow what I show in figure 48 for ease of troubleshooting.

Position the stomp switch with its terminals parallel to you as shown in the left-hand pic. Start the wiring by connecting the two terminals at the top left with a very short piece of bare wire, and then solder. When making the solder terminations to the switch, take care to route and dress the leads as shown; it’s important to being able to position them in the case later. The right-hand pic is annotated to show which termination goes to which contact (Fig. 49).

Initial Testing

Are you ready to test your work?  Plug in pots, jacks and stomp switch as shown in figure 50. Set both controls to their mid-points. Connect your guitar and an amplifier and connect a battery to the power leads. If you don't get boost, click the stomp switch. Got boost?, Tone control works? CONGRATULATIONS!

If your build doesn't work yet, don't be too discouraged. Take a shower and grab a bite, since we know that you haven't done either one since you started this thing; troubleshooting requires a clear head and normal blood-sugar level. The first rule to keep in mind is that projects like this are all-or-nothing. If EVERYTHING is correct, the build works; if ONE thing is wrong, it doesn't. But you have something going for you: I built from the drawings shown here, and you can rely on them. Use them as your bible, and you'll find out what's wrong.

To start troubleshooting, make clean copies of both the schematic and the layout drawing. Use a highlighter to mark off connections as you check them. Go over the off-board connections first. If those look good, you have to verify the interconnections. Use the continuity setting of your multimeter to make sure that you actually have a connection between every point in the layout that is supposed to be connected, and that nothing is shorted. Found a bug? Time to do repairs.

You can also use the low-voltage scale of your meter to sniff out problems. With  your guitar plugged in (necessary so that the battery circuit is complete), hang the negative lead on the sleeve of the input jack. You should see roughly the following voltages on Q1: Collector 5.48 volts, Base 2.39  volts, Emitter 1.77 volts. If any of your readings are off these by more than 10%, you probably have a wiring error.

Once everything works, you can add the in-use LED and then proceed to the section on finishing the enclosure.
Installing The LED

An LED is a diode, and so is polarized. By convention, they are supplied with the negative lead shorter than the positive. Insulate the leads using short pieces of spaghetti tubing, and then bend the ends away from each other (Fig. 51).

Solder the leads to the pads on the underside of the board. Positive goes to U-4 and negative to V-4 (Fig. 52).

Before you go further, re-assemble your test setup and make sure that the LED works properly. If it does, the board is finished.
Finishing The Enclosure
All the finishing methods I am familiar with begin with sanding to produce a smooth finish that will be friendly to paint, powder-coating and/or decals. I like to wet-sand starting with 220 grit Carborundum paper, and I use progressively finer grits up to 600 to get a smooth finish. You can get ideas and techniques for decorating and labeling from many on-line sources as well as some of the other project articles at SBE. After decorating, I always put a soft cloth down on my bench so that there is less chance of ruining a paint job. Move slowly, especially when you have a tool in your hands!
Final Assembly

The next step is to wire and install the DC power jack, the male power connector and the battery snap. Begin by slipping a ¾” length of heat-shrink tubing onto the positive battery snap lead. Crimp the lead to the terminal on the jack, solder, and then conform the tubing to the connection using the side of your soldering iron.

In a similar way, attach the positive power connector lead. The negative leads for the battery snap and the power connector go to the ground terminal, and no insulation is needed (Fig. 53).

Before installing the assembly, thin down the shoulders of the insulating washers so that they will allow the washers to “grab” properly and not let the jack rotate. This can be done with sandpaper, or a grinding stone on a Dremel tool is ideal, if you have one (Fig. 54).

The potentiometers have anti-rotation tabs that need to be cut or bent off (Fig. 55).

 
Mount the power jack assembly first, then the pots. Take care to get the correct pot on each side. All hardware should only be finger-tight for now.

Mount the input and output jacks, dressing the leads as shown to keep the plugs out of the way of the stomp switch (Fig. 56).

Mount the stomp switch, being sure to orient it so that the plug assembly is on the right. The battery snap leads go between the jacks and around the stomp switch (Fig. 57).

Move the plugs aside enough to ease the board into place (Fig. 58).

Plug in all of the connectors. Maneuver the LED into its mounting hole and set the board down on its standoffs. Install one of the round-head screws to hold the board down temporarily. Connect your gear and a battery (Fig. 59).

 

 Test the pedal. If something does not work, first make sure that all of the plugs are fully inserted and that none of the pins on the wires have worked loose. It's also possible that a connection broke during assembly or something is shorting inside. You may have to disassemble and go back to the troubleshooting section above.

Once everything works, finish securing the board. The threaded studs secure the side of the board that is next to the battery, and two of the screws that secure the lid will screw into them. To complete the job:

  • Tighten the hardware on the controls and jacks
  • Secure the lid
  • Stuff a small piece of foam padding over the battery
  • Install the battery cover
  • Install knobs
  • Install rubber feet
Enjoy your new pedal! More builds employing the modular approach of the Bare Box #1 are under development. Comments and suggestions are welcome at smallbearelec@ix.netcom.com.
A Parts List
Presuming that you have all the parts in the breadboard kit, here's what's needed for the build in the Bare Box #1:
1 Bare Box #1 (with 6 screws and 2 studs) 0350
1 DC Power Jack - Long Bushing 0612D
1 3PDT stomp switch 0200
 2 Knobs for 1/4" shaft 0825C
2 Molex 3-pin vertical headers 0614S
3 Molex 3-pin plugs 0614U-2
2 Molex 2-pin plugs 0614U-1
2 Molex 2-pin horizontal headers 0614R-1
1 Molex 3-pin horizontal header 0614S-1
1 Molex 6-pin horizontal header 0614T-1
1 Molex 6-pin plug 0614U-3
19 Terminated leads 0614O
1 Pad-per-hole perfboard 0355
1 Bare tinned wire 0509

A kit that includes everything on this list is available as SKU 0016C.
Stuffing The Board For The Generic Build
Below are the board layout and a re-cap of the parts list. You are seeing it in "X-Ray" view; the red lines are connections that we will make with bare wire on the bottom of the board.
R1 4.7 Meg
R2 1K
R3 120K
R4, R5, R8, R10 47K
R6 10K
R11 10K
C1 100 mf.
C2, C6, C7 .01 mf.
C3 .47 mf.
C4 22 mf.
C5 1 mf.
Q1 2N2222A or similar
D1 1N5818
Print a copy of this drawing and the schematic so that you can mark off connections with a highlighter as you work. This is one of my time-tested methods for catching mistakes before they cost me time and frustration.
The transistor is at the center of the action, so I suggest installing that first. I don't cover basic soldering techniques in this article, so you may want to check a reference and do some practicing if this is your first build. Install the transistor with its Emitter at index L-7. Though modern silicon devices can tolerate normal soldering heat, it is good practice to use soldering tweezers as shown as a heat sink (Fig. 61). Bend the transistor leads flush to the board .Solder in place and trim excess wire (Fig. 62).

All of the resistors are formed for four holes, so the leads are simply bent close to the body. They can be installed in any order, and heat-sinking is not needed. An easy way to begin is with R8, which goes from index P-7 to S-7. Hold the component in place with soldering tweezers, solder, and trim leads (Fig. 63). Then add R4, R5, R10 and R11. Continue with the rest of the resistors on the left side, R1, R2, R3 and R6 (Fig. 65).

 
OK, capacitors. C2, C3, C6 and C7 are polyester-metal film and have no polarity, so they can be inserted either way. C3 may span three to five holes depending on the make (Fig. 66). Again, use soldering tweezers to hold the component in place while soldering. When adding the electrolytic capacitors, C1, C4 and C5, observe polarity! The same caution applies to installing diode D1 (Fig. 67). The LED will go in last during assembly. The board is now stuffed and we can begin to wire.

 
Let's do the ground bus first, starting at index E-3, the negative side of capacitor C4. (I'll show you later when we do terminations how to make the connection to E-1.) Cut a length of bare wire about 2" long. Using soldering tweezers to hold the wire, butt it up to index E-3 as shown and solder (Fig. 68).

Using the chain-nose plier, make a sharp right angle bend down column A. Cut the wire so that it just butts against index A-9 where resistor R-1 terminates. "Tack" the run in the corner where you made the bend. Hold down the run with tweezers and solder to join at index A-9 (Fig. 69).

Before you continue the run, use the soldering iron to remove the remaining pad material around the mounting holes that were added earlier. Butt the remaining wire against index A-9 and solder to join it to the pad (Fig. 70).

Now make two right-angle bends, one at A-12 and one at C-12. Tack the run at C-12 and cut off at C-14 (Fig. 71).
 

Now extend this part of the ground bus to R5 (Fig. 72) and end it at C7 (Fig. 73). A little bit of soldering connects resistor R10 to index T-12 (also Fig. 73), and let's stop and do a test. According to the layout, we should have a connection all the way from the negative side of C4 to one side of C7, right? We can't easily test continuity from C4, but we can absolutely test from R1 to R5 (Fig. 74). Got a good connection? If not, check your soldering. If all is OK, mark off the section you have tested on the layout, the schem, or both (Fig. 75).
If your meter has a capacitance scale (as many do), it's possible to test continuity through a section that contains a capacitor. Let's get the + side of capacitor C1 connected to diode D1 (Fig. 76) and I'll show you what I mean.

You can see in the pic where I have made the connection between the + side of C1, R6 and the negative side of the diode. I have also made the connection between the negative side of C1 and the ground bus. So it would make sense that if I measure capacitance from the negative (bar) side of D1 to any point on the ground bus, I should see about 100 mf. I see 86.8 here, and that's within the normal 20% tolerance for an electrolytic, so I'm good. Use this technique wherever convenient to help ensure correct wiring!
Next, lay down the positive supply bus starting at index E-5. Tack it at B-7 and B-11 for mechanical stability. Then pick up one side of resistor R3 and end on one side of resistor R11 at index U-9.

Join one side of resistor R5 to one side of resistor R3 and pick up one side of resistor R4. Then do a run to one side of capacitor C3. The opposite side of C3 terminates at the Emitter of the transistor, and that's a good point from which to do the capacitance/continuity test if you can.

Here is a list of the remaining connections in the order in which I did them with some notes where I thought they would be helpful:
  • R1 to R2. Avoid getting solder on pad D-8 when making this connection, because we will add a termination there later.
  • R2 to C2
  • Index H-1 to index J-7. Leave index G-7 clear for now. After we do the terminations later, you can test continuity from the Emitter of Q1 to this point.
  • Base of Q1, one side of capacitor C2 and one side of resistor R4
  • Collector of Q1 to positive side of C5 and join to R6
  • Negative side of C5 to capacitor C6 and pick up one side of resistor R8
  • Leave index P-1 open for a termination. Start a run from just below index P-1 to one side of capacitor C6 and one side of resistor R10
  • Leave index R-1 open for a termination. Start a run from just below index R-1 to one side of resistor R8 and one side of capacitor C7
  • Leave index S-3 open to add the + side of the LED later. Start a run from just below index S-3 to one side of resistor R11
  • Leave index T-3 open to add the - side of the LED later. Start a run from just to the right of index T-3 to just short of index W-4

The board is wired, and we can prepare to connect to off-board components.
Terminations
Too many DIY builds will have you insert leads in the holes (Fig. 82), connect to pots, jacks and switches and then stuff the board in the enclosure. I find these methods tacky and won't teach that way. One "right" way to terminate to an off-board component is to insert a push-in terminal (I call these "flea clips") into the appropriate hole and solder on the underside of of the board. Then you can mount the board on standoffs and wire to the terminals.

Start with the hole at index E-1. Enlarge the hole slightly by "working" it with an awl or straight pick (Fig. 83). Squeeze the bottom of the terminal slightly with the chain-nose plier (Fig. 84), insert in the hole, and push down in the top slot--firmly and steadily--with the side of a small screwdriver to seat the terminal (Fig. 85).
In many cases, you can immediately solder the terminal in place on the bottom. I wanted to bridge the one-pad gap to index E-3, so I made use of the fact that the terminal has a hole in the bottom for inserting wire. I re-opened the flange with a pick to enlarge the hole, slipped a bit of wire in (Fig. 86), soldered and trimmed (Fig. 87). Done.

The remaining terminals are installed at indexes F-1, G-1, J-1, P-1, R-1, D-8 and W-4 (Fig. 88). The board is finished, and the next step is to prepare the enclosure.

If you bought a kit, the enclosure is already drilled. If not, and you are rolling-your-own in a 125-B box, you can download from here a page of drilling templates. Never used these? Here is a quick review of my methods:
  • With a good, sharp scissor, cut out the top template.
  • Attach a couple of pieces of double-sided clear or masking tape to the box, and carefully center the template to the cover.
  • In the same way, attach the templates for the sides, being careful to get the holes for the jacks in the correct locations to the right and left of the switch.
  • Use a scribe or scratch-awl to put a small dent at the center mark of the hole for the stomp switch (Fig. 89).
  • If you use standard twist drills, bore a 1/8" pilot hole, enlarge it with a ¼" drill, and then use a tapered reamer to slowly bring the hole to its final size.
  • Follow the same procedure for the other three holes on the top, and then the holes on the sides.
  • De-burr all of the holes with a small, round file. Remove all of the templates and tape, and you should have the result shown (Fig. 90).

Note: Many people like using a step drill (the common trade name is Unibit) rather than separate drills, because it does a quick, clean job of boring any size hole from 1/8" to 1/2" (Fig. 91).

Before installing standoffs for mounting the board, do any painting or decorating that you want to. There are so many choices and methods for how to do this that they really need a separate treatment. You can find lots of discussion and useful infomation by searching past threads on the Forum. Once the enclosure is decorated, you want to keep it from accidentally being dinged while you work. Put a soft cloth down on your work surface to protect the face, and Move Slowly, especially when you have a tool in your hands (long experience!).
I have noted that I insist on using standoffs of some kind to anchor the board rather than supporting it on a few wires and stuffing the case with styrofoam. There are numerous metal and/or plastic hardware items that can be used to secure a board, and the choice depends on a mixture of mechanical needs and cost. Plastic standoffs (Fig. 92) won't fly here because the board butts against the walls of the box. Better, in this case, to use epoxy cement to attach aluminum studs (Fig. 93) to the case. Done right, this results in a gig-worthy and reliable build. The ones shown are hex-shape, 3/8" long and tapped for a 4-40 screw, Keystone #1892. The kit includes four of them and four screws.

First job is to mark the areas in the enclosure that need to be prepped. Set the LED in place temporarily at indexes S-3 and T-3, and lower the board into place (Fig. 94). The LED should be exactly vertical its holes. Now mark the locations of the mounting holes with a pick or scribe (Fig. 95). This indicates the areas where the surface of the box will need to be cleaned.

With coarse sandpaper (80 or 100 grit), roughen the marked areas on the floor and on the walls above the marks. Then scrub thoroughly with a Q-tip wetted with acetone.

Screw the studs to the board (finger-tight only) and prep them the same way that you did the box--roughen and clean up with acetone.

Again place the LED temporarily and set the board in place. Take care not to touch any of the surfaces you prepped.
Mix a small volume of quick-setting epoxy cement (I like J-B Weld). Apply a small amount of the epoxy to the accessible areas at the base and sides of the studs. WAIT a few hours until the epoxy has cured thoroughly and then remove  the screws. Take out the screws, remove the board and beef up the epoxy all around each stud, taking care to avoid the LED hole.. NB: If you don't like having to go through all of this (and I really don't, even though I know it's necessary), check out the Bare Box #1; the studs are cast into the side walls and all of the gluing is eliminated.

Prepare the LED for mounting by cutting two 3/8"-long pieces of vinyl tubing (saved scraps from insulated wire work for this) and sliding on to the leads. The shorter lead is negative. Using the chain-nose plier, bend the leads at right-angles to each other. Cut down the ends and solder in place on the bottom of the board, being careful to observe polarity. When you assemble now, the LED will drop into its hole.
I know that you were wondering if we would ever get here...We are ready to wire! Install the stomp switch and jacks, orienting all as shown with hardware on finger-tight.
  • Wire from the Ring contact of the stereo jack to the center-pin contact of the power jack. The center-pin also gets the negative lead of the battery snap. The positive battery snap lead goes to the switched contact. Refer to figure 4 if you need to.
  • Create a ground run that connects the sleeve contacts of the jacks. The sleeve of the stereo jack gets a connection that will terminate on the board later. The sleeve of the mono jack gets a connection that will terminate on the stomp switch later.
  • The board can be installed.
  • Wire the stomp switch: Solder a jumper between contact #1 and contact #4. Use different colors of wire to make tracing easier. Rout the wire from contact #6 under the board. This will terminate later on the tone pot.

Solder short different-colored leads to the terminals of the (5K) boost potentiometer and mount the control with hardware finger-tight. Take care to solder each terminal to its correct termination on the board. The ground connection from the jacks and the CCW terminal of the potentiometer both terminate at index E-1.

Install the tone potentiometer in the same way. The lead from the stomp switch goes to the center terminal. Make the short connection to the power jack from the + power input of the board.
The pedal is ready to test. Connect a battery and your gear and see if the controls work. I built exactly what you see here, so you should have action if everything is as posted.

To complete the job:

  • Tighten the hardware on the controls and jacks
  • Secure the lid
  • Stuff a small piece of foam padding over the battery
  • Install the battery cover
  • Install knobs
  • Install rubber feet
Troubleshooting

The first rule to keep in mind is that projects like this are all-or-nothing. If EVERYTHING is correct, the build works; if ONE thing is wrong, it doesn't. But you have something going for you: I built from the drawings shown here, and you can rely on them. Use them as your bible, and you'll find out what's wrong.

To start troubleshooting, make clean copies of both the schematic and the layout drawing. Use a highlighter to mark off connections as you check them. Go over the off-board connections first and verify that the connections to power, jacks and switch are correct. If those look good, you have to verify the interconnections. Very Carefully, disassemble the pedal and lift the board and controls out of the enclosure. Use the continuity setting of your multimeter to make sure that you actually have a connection between every point in the layout that is supposed to be connected, and that nothing is shorted. Found a bug? Time to do repairs.

You can also use the low-voltage scale of your meter to sniff out problems. With  your guitar plugged in (necessary so that the battery circuit is complete), hang the negative lead on the sleeve of the input jack. You should see roughly the following voltages on Q1: Collector 5.48 volts, Base 2.39  volts, Emitter 1.77 volts. If any of your readings are off these by more than 10%, you probably have a wiring error.
Enjoy your new pedal! More builds employing this basic two-knob platform are under development. Comments and suggestions are welcome at smallbearelec@ix.netcom.com.
A Parts List
Presuming that you have all the parts in the breadboard kit, here's what's needed for the generic build:
1 Enclosure 125-B 0306B
1 3PDT stomp switch 0200
 2 Knobs for 1/4" shaft 0825C
4 Studs 8009
4 4-40 Screw x 1/4" 8003
1 Pad-per-hole perfboard 0355
8 Push-in Terminals 0400C
1 Bare tinned wire 0509
1 Hookup Wire  

A kit that includes everything on this list is available as SKU 0016D.