Adjustable input levels – Erica Synths EDU DIY Mixer Eurorack Module Kit User Manual
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ADJUSTABLE INPUT LEVELS
And while our circuit does work pretty well now, it’s still missing a key feature: knobs to
adjust the individual input levels. Thankfully, adding them is fairly trivial –
we just need to
set up three potentiometers as variable voltage dividers (also called attenuators)
between our input sockets and the 100k resistors
The idea here is this: if we send an audio signal through a standard voltage divider, we’re
able to pick up a scaled-down version of that audio signal at the divider’s output. The
factor by which it’s scaled down depends on the relation between the two resistors.
Conveniently, a potentiometer is basically a voltage divider as a standalone
component
– where you can change the resistance relation by turning a knob. This way,
we’re able to adjust the signals’ volumes to any level between 100 and 0%.
Once you’ve set this up, play with the three potentiometers. You should be able to adjust
the individual channel levels.
Read more about potentiometers in the components & concepts appendix (page 25).
You can try this chapter’s circuit in a circuit simulator. I’ve already set it up for you right here:
you can change all values by double clicking on components.
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