Introduction
Difficulty Level: Intermediate
Build Time: 3 hours
This guide will provide step-by-step instructions for assembling the Zeitgeist pedal, covering the entire process from start to finish. To successfully complete the assembly, you will need the following materials and tools:
Materials
Zeitgeist DIY Kit
Soldering Iron
Solder
Side Cutters
Wire Strippers
Tweezers/Needle Nose Pliers
Socket Set
Additional tools that might be useful during the assembly process include masking tape (to hold components in place while soldering), isopropyl alcohol (for cleaning solder joints), and de-soldering braid (in case you need to undo any mistakes).
Steps for Completing the Build
Review the bill of materials (BOM)
Solder the components to the front and of the PCB
Solder the audio jacks and foot switch PCBs
Connect the audio jacks and foot switch to the main PCB
Place banana jacks and SPT switch washers on board
Connect the DC jack and banana plugs to the main PCB
Place washers and nuts onto the hardware
Test the Zeitgeist
Review the bill of materials (BOM)
Here is the BOM which lists the parts included in the kit, make sure to verify your kit has all the components listed below. The kit includes a printed BOM for your reference. There are part numbers listed in the BOM incase you need to replace any parts in the future.
Solder the components to the front and back of the PCB
To initiate the construction of the Zeitgeist module, begin by soldering the components onto the front side of the PCB (the side featuring the CCTV logo in the bottom right corner). It is recommended to complete the front side assembly before moving on to the components on the back side.
Start by soldering the resistors and diodes, ensuring that the orientation of the diodes matches the silkscreen markings on the PCB. To facilitate tracking the placement of each resistor on the board, you can refer to the color-coded PCB layout provided below. You may have a few extra components in your kit.
After soldering the resistors and diodes, proceed to solder the ICs, capacitors, transistor, and power regulator onto the PCB. Pay attention to the following points when soldering these components:
Differentiating between the power regulator (labeled 78L05 on the silkscreen) and the NPN transistor (2N3904): These two components may look similar but can be distinguished by reading the label on the flat side of the package. Ensure you have each component in its correct position before soldering, as swapping them could result in damage to the ICs and other components.
Orientation of the 2u2 capacitors and LED: Insert the 2u2 capacitors with the long positive leg into the pad marked with a '+' sign. The same applies to the LED on the back of the PCB. The ICs also have a specific orientation indicated on the silk screen that should be followed. Both ICs have their notch pointing to the left.
Consider soldering C13 slightly higher: To create more room for the 'IN' audio jack, you may choose to solder C13 slightly higher rather than flush to the PCB.
The three pin header needs to be soldered (short pin down) in the Pre/Post position. The plastic jumper is used to select whether the output is pulled from the Pre section or the Post section
Pre - a mix of wet and dry is sent to the output
Post - only the wet is sent to the output.
Once you have soldered the components on the front side, you can proceed to the back of the PCB. Here are some guidelines for soldering the components on the back:
Standoffs for the photoresistor/LDR and LED: The LED uses the shorter 8mm standoff, while the LDR requires the longer 10mm standoff. These standoffs have channels to secure the leads and hold the components in place.
Be cautious with the soldering iron: Take care not to melt any plastic components on the PCB while soldering.
Solder the audio jacks and foot switch PCBs: The audio jacks and stomp foot pedal come with their own PCBs, which simplify the connections. Insert the audio jacks onto the PCBs with the TRS labels facing upwards, as shown in the provided photo.
Inserting the stomp box switch: Pay attention to the orientation of the pins and ensure that the CCTV logo on the PCB is on the opposite side from the switch. The pins should face vertically towards the logo.
Solder the audio jacks and foot switch PCBs
The audio jacks and stomp foot pedal are equipped with their own PCBs, which simplify the connection process. Follow these steps when working with these components:
Insert the audio jacks onto their respective PCBs: Ensure that the TRS labels on the audio jacks are facing upwards, as depicted in the provided photo.
Insert the stomp box switch into its PCB: Pay close attention to the orientation of the pins. It is important to have the CCTV logo on the opposite side from where you insert the switch. The pins should face vertically towards the logo.
Connect the audio jacks and foot switch to the main PCB
Begin by removing the nuts and other fittings from all of the hardware, as they will be mounted to the enclosure later in the process.
On the bottom of the stomp box PCB, you will find pads labeled 1 - 6, which correspond to the pads on the main PCB board. The kit includes red, black, and white wires, allowing you to follow the color coding used in the build guide. Strip and twist the wires, then insert them through the appropriate holes in the main PCB.
For the audio jacks, the audio input and output jacks only require the tip and sleeve connections, which are the two outer jacks. The middle expression jack requires the tip, ring, and sleeve connections. Solder each audio jack to their respective audio jack PCBs, and then connect them to the main PCB mating T to T, S to S, and R to R.
Place banana jacks and SPDT switch washers on board
Prior to soldering banana jacks onto the main PCB, solder resistor leads onto the terminals of each jack and mount them to the enclosure. These leads will be used to connect the jacks to the PCB at a later stage. Additionally, attach the washers onto the SPDT switches and secure the banana plugs onto the enclosure. It is crucial to add the washers to the switches now, as accessing them after soldering the DC jack will be difficult. Note that the tab on the switch washers should face away from the enclosure.
***Note: I messed up here in the above photo (the white and black banana jacks should be switched so they match the below photo)***
Connect the DC jack and banana plugs to the main PCB
To secure the PCB in place while soldering the DC jack, take a few nuts and fasten them to the potentiometers. Double-check that you have connected the banana jacks to the correct outlets. Apply solder to the leads of the DC jack, keeping in mind that the longer lead is the positive lead. Place the nut on the jack to secure it in place.
Using a pair of tweezers, reflow the solder on the jack while carefully positioning the wires onto the leads. It's important to complete this step swiftly to prevent the wire casing from melting.
Next, take the resistor leads that were soldered to the banana jacks and insert them into the holes next to the banana jack cutouts. Refer to the provided picture for guidance.
Place washers and nuts onto the hardware
Finally you can place the fittings for the potentiometers, 3.5mm jack, audio jacks, and foot switch. Here are some notes on placing the fasteners in the correct order.
Stomp switch: Inside the enclosure place one nut, then the plastic washer, then the lock washer. On the outside of the enclosure place the other nut.
Audio jacks: place the washer then the nut, the audio jacks should be turn to the side when put in place so they do not short to the enclosure.
3.5mm jack: place the nut on the outside of the enclosure
Potentiometers: Simply place the nut on the outside of the enclosure, while building the pedal we found the knobs felt better without adding the washers, add the clear knobs onto the potentiometer shafts once they are fastened.
Test the Zeitgeist
To test the functionality of the Zeitgeist module, connect a center negative 9V power adaptor to the DC jack. Activate the foot pedal, and the LED should turn on, indicating that the pedal is operational.
The header labeled PRE|POST allows you to control whether the dry signal is included or removed from the effect. Selecting "Post" will remove the dry signal, while choosing "Pre" will include it. The "Post" option is particularly useful for utilizing the Zeitgeist in an effect send configuration, where only a wet signal is required.
Here are some troubleshooting tips that I recommend:
Connect the DC jack and banana plugs towards the end of your build, as disassembling the pedal becomes more challenging once these components are in place.
Ensure that the stomp box PCB is correctly oriented before soldering it to the switch. Refer to the provided photos to verify the correct orientation.
Double-check that you have inserted the PT2399 and TL074CN ICs in the correct direction, aligning the 'U' at the top of the ICs with the 'U' on the silk screen.
Verify that the polarized components (LED, electrolytic capacitors, diodes, etc.) have been soldered in the correct orientation to ensure proper functionality.
