Step 6:
Add the 25k and 50k Trim pots. Note that there are 5 holes on the PCB, but only
3 leads on the actual trimpot. Please do not let this confuse you. This is so that the PCB
can accommodate a variety of trimpots. There should only be one way to fit the trimpot
into the PCB. You do not need to bend the leads to make it fit (unless the leads were bent
in shipping).
You will need to adjust the trimpot when you are finished building the pedal. The 25k
adjusts the circuits bias voltage and the 50k trimpot adjusts the sine wave symmetry. You
start by setting the trimpots at the middle of its rotation or “noon”. This will get you
started and should definitely produce a chorus sound when you plug in for the first time.
You fine tune the bias trimpot by strumming or plucking as hard as you can and dialing
the trim pot till you get the least amount of distortion. If you have a guitar with hotter
pickups, you should use it for this step. You will need to have the wave toggle switch in
the sine position to adjust the sine wave. You do not need any special tools for this. Just
use your ears.
