Erica Synths EDU DIY Wavefolder Eurorack Module Kit - Manual (Page 12)

This means that we have two distinct regions in our graph above: one where the
collector voltage is roughly the inverse of the base voltage – and one where it’s
roughly the same
. So if we send an oscillation into the transistor’s base, every part of the
wave that crosses the 450 mV threshold will be folded over in the output. To make sure 7
this actually works, let’s set it up on the breadboard.
If you now send a triangle, sine or sawtooth wave into the jack socket connected to the
transistor’s base while monitoring the voltage at the collector with an oscilloscope, you
should see some folding happening.
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To make the e ff ect easier to understand, I recommend you route the input through a mixer
before sending it into the circuit. That way, you can play with its volume to see what
this does to the output . (Spoiler: more volume means more noticeable folding – simply
because a bigger part of the triangle is passing the folding threshold.)
You can try this chapter’s circuit in a simulator. I’ve already set it up for you right here: https:// 7
tinyurl.com/2zasufbu – you can change all values by double clicking on components.
If you have the mki x es.edu VCF, you can get a sine wave by turning up the resonance all the 8
way without any input signal.
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