This is photo-journal of building MadBean’s “Harbinger 1.5” Uni-Vibe circuit PCB, done up in a 1590BB enclosure. (It’s a long read, so you might want to get a cuppa before digging in. WARNING: Circuit Porn.) It can be built in either a standard 9v DC center negative construct, or the builder can opt for the 18v DC supply version. The details are in the build docs for this project.
I always start by first reading the build document a couple of times. (Familiarity is helpful.) Next, I ensure I already possess all the components as defined in the BOM; cross-checking with the ‘shopping list’ and examining the schematic. This takes a little more time, but ensures the build will go smoothly. Then I check the enclosure, PCB, and other hardware to see how easily things will fit once the guts are assembled. By loosely placing the PCB and hardware bits into the box in proximity of where they will most likely sit when finished, I then know I can proceed with the build with what I have.
To ensure the PCB mounted pots will wind up where they are supposed to go, I like to lay the PCB down into the enclosure and use a mechanical pencil to mark the borders. I’ll also extend the lead of the mechanical pencil so I can mark where the center leg of each pot, switch and any LEDs will go. With the inside of the enclosure pencil-marked. I will then measure the distance of the pot legs to the pot center and add that distance to identify where the pot shaft and other holes should be drilled. I drill the pilot holes from inside the enclosure and afterwards, drill them to their respective proper sizes for hardware mounting. At this point, the enclosure is committed to the build.
Populating the PCB is the next step and I prefer to start with the lowest laying components first - the resistors. I place, solder and clip about a dozen resistors at a time. This minimizes the number of protruding leads than can interfere with soldering a PCB that has too many leg extensions sticking out here & there.
Next to populate are the larger, close-to-the-ground components like diodes, sockets and trimmers. Then onto film & ceramic caps and transistors. (In some cases, depending on the build, I socket transistors. But in this build, I’m a confident solderer and know the trannies being used are sturdy.) I populate electrolytic caps and special components last. In this case, the lamp, LDRs and shroud cap retaining legs are last. At this point, it’s a good idea to flip the PCB over and apply a good bit of isopropyl alcohol and rub vigorously with an old toothbrush to clean off any excess flux.
With the PCB fully populated, I will the do a stuffing test by mounting the pots, LEDs and other hardware into the enclosure and squirreling the PCB onto the pot, switch & toggle legs. In so doing, I take careful note of how the PCB sits in the enclosure to see if it is higher on any one side than the other. Such un-even-ness often occurs on builds where there are both pots and toggle switches mounted to the PCB. Sometimes one is higher than the other. To get the PCB to rest level, I will use one of the toggle switch nuts to set the height (length) of the threads that will protrude thru the enclosure. Then I’ll use a straightedge to check the level compared with the pots. Once the toggle switch adjustment nuts are set to the right depth, I hit them with a dab of nail polish to hold them in place for the duration of the build.
Knowing that everything fits properly, sits evenly and I’ve not burned any fingers or toes in the soldering process, I’ll then commit the pots and toggle switches to solder on the PCB while the pots and toggles are fixed to the enclosure. Then, since everything is in place where it will sit when the build is complete, I start preparing the wiring by carefully measuring and place-testing each length of wire before cutting and stripping the ends. I then pre-bend each piece of wire re-test-fit it for loose precision.
Once all the wires have cut, stripped and bent to shape, I remove the guts and either replace them onto a cardboard version of the enclosure top or just wing it and start soldering the wires in small groups. On this build I started with the stompswitch because it has the largest ‘group’ of wires in one location. Then I went on to add the jack wiring. Here was a good spot to conduct a quick test to ensure the stompswitch and LEDs work, so I tack-soldered the DC jack on and fired it up to see if the worked properly. (This is that bit where you may or may not have heard to “rock it before you box it.”) Yay! It works!
Meanwhile, during solder breaks or other interruptions, I would conjure up some artwork with Photoshop and get some waterslide decals printed out, clear-coated and dried.
After everything is wired, (except the DC jack, because it is soldered last after stuffing), the pedal gets another stuff-test and the DC jack gets soldered to the DC supply lines for the initial in-box test. Yay! It still works! But now, I have to remove the guts again so the enclosure can be finished. Heat up the soldering iron again, remove the DC jack, remove the guts and LED bezel and clean the enclosure with an 800 grit sand paper. Washed the enclosure with Dawn dish soap, rinsed thoroughly and let dry. (I used a blow dryer cuz my decals were ready to get laid.)
Final steps: apply the water slide, let dry a day, another half-dozen coats of clear, a dozen light coats of MinWax, re-stuff the guts and solder the DC jack, ensure everything is tight, fire up, test, adjust the offset and gain trimmers to taste, sign the bottom plate of the enclosure and close it up. Voila! It’s a Vibe!
It’s not even a neat or organized workspace. But it gets the job done. Thanks for reading.
Looks like a Pork Barrel (CE-2 circuit) build is on the horizon. Happy building!
