Step-by-Step: Building the Business Card Boost Pedal

A few weeks ago, I received the first round of my new business cards. Like many of my fellow pedal builders, I designed a specialized printed circuit board (PCB) that serves double duty. Like a standard business card, it includes my contact information – but the recipient can take a stab at building their own pedal when they get home. For details about the component values, including the choice from two separate effects pedals, click here. Please note: this build diary features an early business card – after the first run of twenty, there is an additional resistor to limit the current to the LED. This resistor is located at the lower left, near the LED.

Step 1: Gather the Components

Like preparing to bake a cake, the first step in the process of building the BC Boost is to gather all of the components you will need to complete the build. Visit the BC Boost instruction page and collect the parts listed in the bill of materials. Note that the values vary depending on the boost you choose to build (Cranberry vs. Fetzer). There are a variety of sources online – feel free to contact us for recommendations.

For this build, I used my PCB mount – a neat tool that I found online. These can be purchased on eBay or Amazon and hold the PCB at a better angle for working. It also rotates so both sides of the PCB can be accessed without removing it from the mount. The BC Boost can be built without this tool, but it makes life a lot easier. If you plan to build multiple pedals, this is a wise investment.

Step 2: Install and Solder the Lowest Level

The BC Boost is a very simple circuit with minimal components – but it’s always a good idea to use best building practices. Start by installing and soldering the components that sit closest to the PCB. In this case, this step includes only resistors, but other circuits may include diodes and even axial capacitors that can be included in this layer. You may want to bend the leads of the components slightly as you install them to hold them in place when you flip the board over to solder.

Soldering is not difficult, but it does take some practice. There are a wealth of tutorials online, including videos on YouTube that will give you more guidance than I can in this write-up. You may want to practice some solder joints before you move on to the BC Boost, but you should find it easy to solder to the PCB.

Step 3: Install and Solder Taller Levels

The BC Boost only has two levels of components the way I built it. The capacitors and the transistor I used were both the same basic height off the PCB. More complex circuits you may build down the road will have more than just two layers. Use your best judgement as to the order of assembly. Work from shortest to tallest components, soldering and clipping between each step. If a circuit has integrated circuits (ICs) that are socketed – a good practice until you are confident in your soldering skill – I install those last. Sometimes I even wait until the pedal is complete and install the IC immediately prior to testing.

Once the components are all installed, remove the PCB from its holder. If the flux residue around components bothers you, feel free to gently clean this off with isopropyl alcohol.

Step 4: Install the Footswitch, LED, and Potentiometer

Make sure to orient the board the correct way – the components you have already installed will go on the opposite side of the PCB as the footswitch, LED, and potentiometer (pot). The footswitch should be installed as pictured, with the lugs parallel to the short side of the PCB. Solder one lug at a time – you don’t need to fill the entire hole. Just apply enough solder to secure the footswitch and complete the electrical connection. I usually fill about 1/4 – 1/3 of each of the holes. Also be careful not to leave the soldering iron in one place for too long. The lugs will conduct the heat into the plastic body of the switch and extended soldering time can cause damage to the switch.

Potentiometer and LED Options

The BC Boost bill of materials calls for a standard LED and an A100K pot with the longer legs. To install a standard LED in this project, drill the holes using the drill guide (see next step) and then loosely mount the PCB in the enclosure with the LED in its position. Allow the LED to find its place in the LED bezel, which should already be installed in the enclosure. Once you have the LED where you want it, solder the two leads in place. The PCB can now be carefully removed and reinstalled as needed. Alternatively, use an LED assembly with wire leads – you may need to install this in a different location than shown on the drill guide to avoid interfering with the PCB. This second method was used in this build.

If you can’t find the A100K with longer legs, or if you have a standard one on hand, feel free to use wires to connect the pot to the PCB as shown in this build. The footswitch will offer more than enough bracing to hold the PCB in place in the enclosure. Just be careful to orient your wires correctly so that lug 1 on the pot matches lug 1 on the PCB and so on. Lastly – some pots have a little locating tab that sticks out towards where the knob mounts. Clip this off if yours has one – it will interfere with the enclosure since there isn’t a slot to accommodate it.

Step 5: Mark and Drill the Enclosure

The BC Boost is designed to be installed in a standard 125B enclosure, fairly common in the pedal industry. The 125B is roughly the same size as your favorite Boss pedal (mine’s the TU-2 because tuning is important, y’all). You can orient the enclosure however you’d like – with the long side on the bottom, your switch will be on one side and the knob on the other, or with the short side on the bottom the switch will be on the bottom and the knob on the top. Although we haven’t tried it, the BC Boost should also fit in a 1590B enclosure, which is slightly smaller than the 125B (think EHX Nano Series).

Print the drill guide PDF and cut out along the border. This guide is the exact size as the PCB, so you can use it to locate the holes for the switch, LED, and pot wherever you’d like in the enclosure.

Measure Twice, Drill Once

Once you have decided how you want to orient the pedal, locate the drill guide on the enclosure and carefully tape it down with masking tape. Also be sure to mark the locations of the DC power jack and the input/output jacks. In this build I oriented the pedal with the switch at the bottom and the pot at the top, and located the pre-wired LED above the knob at the very top of the enclosure face. I also decided to use top-mounted jacks, as pictured here.

Mark all of your holes with a pen or marker, then use a punch to mark the centerpoint of the hole in the metal. I assure you, the enclosure will be the most costly part of the build so take your time. Finally, drill the holes. Begin with a small pilot hole, then use a step bit to increase the hole sizes to fit the components. Be careful with the step bit – you can always make a hole bigger, but you can’t make it smaller!

Behold, the Completed Enclosure

If you are patient and careful, the drilling is done and your enclosure should look like this. Be aware that the drilling process is messy and produces a fair amount of shavings (most likely aluminum). I recommend wearing gloves to keep the shavings out of your skin, and you will want to carefully clean the area after you drill. Needless to say, drilling is something you want to do in a garage or workshop, not in the kitchen or living room. Feel free to lightly rinse the enclosure after drilling, just be sure to dry it thoroughly.

This is the time to add any art to the enclosure. Stickers work well, but may not last on a gigged pedal. Paint is a good choice, and you can seal the art when you are done with an automotive clear coat. If you use a pre-painted or powdercoated enclosure like I did, you may choose to leave the enclosure bare.

Step 6: Final Assembly and Testing

Final assembly – you’re in the home stretch! Make sure to use lengths of wire that will allow easy installation. There is plenty of room in the enclosure to stash excess length – better to have too much than not enough. Do as much soldering outside the enclosure as you can. Because of the LED and the DC jack I used, I needed to solder those two in the enclosure, but the audio jacks were soldered outside. The more work you can do with extra room, the easier your build will be.

Once everything is soldered up and mounted in the enclosure, give it a test before you close the case. Make sure that the pedal powers on, that the LED turns on and off when it should, and that the signal passes through when the effect is off. This circuit is easy to test – if the knob makes things get louder, you have a winner!

Step 7: Finishing Touches (and Founding You Pedals, Ltd.)

Finish the pedal by installing the enclosure lid and knob. Don’t forget to sign and date your lid – centuries from now, some future guitarist will be in awe of your craftsmanship. For this build, I chose a fancy green aluminum knob to match the green LED. Put your pedal on the ground and rock! Each of the designs you can choose from offers minimal boost, although the Cranberry can be modified to bring the noise!

If you enjoyed building this pedal, I encourage you to try some others. There are a wealth of DIY builds available, including some that give really professional results (check out Aion Electronics kits for some amazing pedals you can put together and modify yourself). Who knows – maybe this crazy world of effect design is for you, too!

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