Th Nonlinearcircuits DP Filter is a really interesting beast.
It takes ideas from the TB303 & Moog ladder and combines this with EMS Diode ladder.
This circuit replaces the diodes and transistors of the ladders with opto-isolators
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Opto-isolators (also called optical couplers or optocouplers) are basically a LED & a photo transistor in a light tight package. They use light to transfer electrical signals between circuits to keep them electrically isolated from each other. In this module the TLP521-2 is used.
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Andrew's Build notes are here:
http://www.sdiy.org/pinky/data/bipolar%20VCFs.pdf
More useful links:
1. Large schematic
2. Module description.
3. Muffs thread
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This module is probably not the easiest one to start with if you are a beginner.
There are lots of surface mounted components, though on the bright side there is only one SMD IC.
(a 074).
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I like to get the ICs out of the way so I'll solder the 074 first.
It takes ideas from the TB303 & Moog ladder and combines this with EMS Diode ladder.
This circuit replaces the diodes and transistors of the ladders with opto-isolators
Andrew's Build notes are here:
http://www.sdiy.org/pinky/data/bipolar%20VCFs.pdf
More useful links:
1. Large schematic
2. Module description.
3. Muffs thread
There are lots of surface mounted components, though on the bright side there is only one SMD IC.
(a 074).
