Article by Logan Tabor -- Nov. 3rd, 2020
Welcome back to another episode of Fix it Friday. Today we are going to take a look at one of Mojotone’s pedal kits - the A/B Switcher Pedal. These pedals often get overlooked, but they can be quite useful in a number of situations. Players who find themselves needing to switch between two guitars or two effects setups, change amps or switch between an amp and tuner, will all benefit from having one of these in their rig. Best of all, it’s a simple circuit that anyone can build! There is no internal PCB for the builder to stuff with components and/or solder components to, and the pedal box itself is not so packed with parts that one would have a hard time working in there.
Before we get started, let’s take a look at the tools you’ll need:
- Soldering Iron
- Phillips Head Screw Driver
- ½” Nut Driver or Adjustable Wrench
- 9/16” Nut Driver or Adjustable Wrench
- Needle Nose Pliers
- Wire Strippers
- Wire Cutters
Okay here we go! First thing we have to do is mount our hardware onto the pedal chassis (this includes our jacks, footswitch, LEDs, and power inlet). This is a pretty straightforward process that will require the use of your nut driver(s) or adjustable wrench. Refer to the pedal’s Wiring Diagram as a reference for where each part should go.
Some helpful things to keep in mind while you’re installing the hardware are the following: First, make sure you apply the faceplate to the pedal before installing the footswitch and LED components otherwise you’ll have to remove these components and start all over again (Image 1A).
When installing the jacks, make sure the two J11 jacks go side by side at the top of the pedal, while the J12 jack goes by itself on the side panel. Make sure all jack lugs are facing up as this will make it easier for you to wire everything when the time comes. Also, make sure you orient the footswitch component so that the holes in the lugs are pointing towards the top and bottom of the pedal chassis (Image 2A).
Once you’ve installed all of the necessary pieces of hardware, you should have something that resembles the pedal chassis in Image 3A below…
Now it’s time to start wiring everything up. It’s best to start with the power inlet and LEDs, so that’s where we’ll begin today. To make things as easy as possible, grab the resistor that came with your kit and wrap it through and around the positive terminal on your power inlet (refer to wiring diagram). We are going to be soldering the red leads from each of our LEDs to the lead of this one resistor. So now we need to cut those red LED leads to length and strip back the ends to prepare them to be soldered (Image 4A).
Once everything is cut to length, you can wrap the red LED leads around the resistor lead and simply apply solder. Then apply solder to the positive lug on the power inlet. Now you can trim off the excess lead material from your solder joints. Once you’re done, you should have something that looks like Image 5A…
At this point, we can take a look at our wiring diagram and begin identifying which connections to solder next. These should include any connection points that only have one component connection to solder. If you’ll notice on your diagram, there is a yellow wire running from the positive lug (or tip) on our left J11 jack to one of the lugs on our footswitch. Notice also, that there is a yellow jumper wire running between that footswitch lug and another footswitch lug. This is an example of a connection we do NOT want to make right now. Let’s wait until the end to solder in these types of joints. For now, let’s find the single component joints and solder them in. We’ll meet back here in a few…
Okay so you’ve made the single-component connections and trimmed the excess lead material off of the ends of your solder joints. Now you should be looking something like the chassis in Image 6A below…
Now we need to complete our final solder connections. This will require us to run jumper wires as they are shown on the diagram. There are only three instances where a jumper is required in this particular pedal circuit. Those would be (in reference to the diagram): the yellow wire coming from your J11 jack, the blue wire coming from the other J11 jack, and the black wire coming from the J12 jack. All of these will need a jumper to a second lug on your footswitch. It’s no sweat, just follow your diagram and meet us back here in no time!
Now you should have something that resembles the chassis in Image 7A below…
At this point, you can choose to put some silicone adhesive on the back of your metal battery clip to adhere it to the inside of the pedal chassis. This, of course, is optional but is certainly recommended if you plan to power your pedal via a 9V battery.
Otherwise, that’s about it! Just use the included screws to fasten the pedal's backplate to the main pedal chassis and voila. I told you it was easy. Very few components, no PCB...piece of cake. Thanks so much for joining us for another Fix It Friday. We’ll see you next time!