The DIY 2-Channel Bag of Parts SpikerBox

Here are the instructions to assemble your very own 2-Channel SpikerBox from the Backyard Brains 2-Channel Bag of Parts! If you haven't already, you can order it through our product page. This 2-Channel is great for earth worm conduction velocity experiments. Depending on your comfort with electronics, it takes 2 hours (electrical engineer) to 4 hours (complete novice) to build. Before you begin, you will need to collect a few things.

Part 1: Build the first circuit board (Channel 1)

Assembly will be done in 3 steps, in this first step we will assemble the PCB board. Below you will find the step-by-step instructions. Navigate through each step until your board is complete, then move on to part 2. .
  • Let's begin building your bag of parts!  In part 1, we will assemble the PCB.
  • You will need a Soldering Iron, some solder, a magnifying glass, a 9V battery, silly putty, a pair of scissors, wire strippers, wire clippers, superglue, and Electrical Tape
  • What's in the kit?  8 Capacitors, 7 Resistors, 1 PCB, 2 cork stickers, 1 logo decal, 2 needles, a speaker, a 1x2 speaker connector, speaker wire, RCA connector, RCA plug, a switch, LED, 2x battery connectors, 1/8 inch (headphone) connector + screws, nuts and enclosure.
  • Install Audio Line Out and Solder the back leads to the PCB
  • Install Power Switch and LED (bulb pointing out)
  • Install the RCA input connector.  You might need to forcably push in the connector, but it will go in.  Be sure the center wire is through the center hole.
  • Identify all of the resistors based on the color coding of the resistor stripes.
  • Bend resistor leads, insert into the approriately labeled position, bend leads, solder, and trim.
  • Repeat this step for all 7 resistors.
  • Identify all of the capacitors based on the 3-digit value code that appears on each cap.  A magnifying glass helps.
  • Install the 8 capacitors.  Note that none have a polarity, save for the 220uF cap (c3).  This cap needs to have the stripe towards the row of connectors.
  • Install Chip Holders. The half circle should point toward the front of the board (where input, switch, LED, and line out are).
  • Install the 9V battery connectors. Take care to ensure the two connectors are flush with each other or else the battery will not plug in. Be careful to align the + and - of the battery, with the + and - on the board. You don't want to cross up the polarity of the 9v.
  • Solder on the Speaker Connector.
  • Install a the female header on the bottom of the board. This will provide the power to the second board you will build soon.
  • Install Chips in holders, with circle on all chips pointing towards top of board. AD623 goes in left holder, TLC2272 goes in the middle holder, and the LM386 on right holder.  When you are all set, you can install the 9v battery and test if the LED lights up!

Part 2: Build the Second Circuit Board (Channel 2)

The second circuit board is the same as the first circuit board, minus some components.
  • You leave out: the switch, the 9V battery connectors, U3, C4, R3, C5, C3, and the SP1 speaker header. Install a header at 'Power'.

Part 3: Build the 2-Channel Electrode and Speaker

Now you are ready to build your two channel electrode. This is a little more difficult than the one channel electrode, but this steps below make it all smooth and easy.
  • You begin with two 6-inch lengths of speaker wire, two RCA connectors, and a red, white, and black map pin.
  • Peel apart the two speaker wire pairs so you have four 6 inch lengths. Cut one length to 3 inches. Strip ~1/4 inch of insulation from each speaker wire end.
  • You will now install the ground wire on the white RCA connector.
  • Twist one end of the 3 inch length and one 6 inch length together, and insert wire into ground hole of connector.
  • Solder the connection and crimp the tabs.
  • Solder the black map pin to the other end of the 6 inch speaker wire length.
  • Solder another 6 inch speaker wire length to the RCA connector
  • Solder the white map pin to the other end of the 6 inch speaker wire.
  • Carefully thread the wires through the wire connector cover...
  • And screw it on!
  • Now install the red RCA connector cover through the 3 inch length.
  • And solder it to the ground connection on red RCA connector.
  • Insert the remaining 6 inch speaker wire length through the red connector cover.
  • And solder one end to the remaining solder lug on the RCA connector
  • Screw the RCA connector cover on the connector, and solder the red map pin on the remaining end of the 6 inch speaker wire. You are done with your electrode!
  • Now time to build your speaker. Cut off the last few inches of the speaker wires.
  • Strip the ends of the wires just a little bit.
  • Solder the wires to the 2-pin speaker connector.
  • Twist the two wires together.
  • Separate and wrap solder joints away from each other using electrical tape.  Take care that the two solder joints do not touch.

Part 4: Final Assembly

We are ready to put together our final assembly of the 2-Channel SpikerBox.
  • You have a long length of tubing. Cut it into...
  • 4 pieces of 3/4 inches, 7/16 inches, and 1/8 inches long.
  • Insert the 2 inch screws through your bottom acrylic (bottom of SpikerBox), and place the 1/8 spacers on the other side of the screws.
  • Slide second circuit board (Channel 2) on screws, and place 7/16 spacers on top.
  • Slide first circuit board (Channel 1) through screws and on top of bottom board (Channel 2). Ensure the connections mate.
  • Install speaker inside top acrylic piece (you may find slightly sanding the hole will make the speaker fit in better), place cork stickers on acrylic , and slide largest spacers (3/4 inch) on screws.
  • Place top case on SpikerBox, and tighten nuts. Flick top power switch. Both LEDs should come on. You should hear a “click” from the speaker as well.
  • Put in your electrodes and your headphone adaptor. You are done! Note that if you turn on the SpikerBox now, you will no longer hear the “click.” The speaker only works when the 2 chan adaptor is not plugged in.