RR480 MK2 CS80 Filter w/ VCA Panel

The Old Crow RR480 MK2 is a eurorack bare board set DIY version of the CS80 filter.

This is for a Panel ONLY in the Eurorack format.

Availability: In stock




The RR480 MK2 is a eurorack bare board set DIY version of the CS80 filter, using the same core circuit designed in 2001 for the MOTM-480, and more recently the M480 MkII. The euro version is a 28HP module that includes two CS80 SVF filters and an "Irwin" VCA. A new feature has been added: an input mode select to allow the standard CS80 HP->LP filter chain or a split mode where two inputs go to SVF1, and one input goes to SVF2. All taps are available for both filters in either mode. 

The VCA is an inverting linear type that has two inputs, one with a level control and one with switchable AC/DC coupling. The rev2.3 board uses 10-volt sub-regulation to allow operation from +-12VDC to +-18VDC supplies. 

Split mode runs two filters in "parallel" with their own inputs and outputs. Their tracking input (1V/Oct) is still common to both, however. This allows you to set a "spread" using the frequency controls and have them track sort of like the way the Moog Voyager does it. SVF1 does track at 2V/Oct so the spread widens as you go up, but you can make this a 1V/Oct action with a resistor change at build time. 2V/Oct is a Yamaha thing on the HPF. And yes, adding switch to select tracking is easily done: 1 switch and one resistor per filter section. 

Specs & Downloads

Specs & Downloads

Manufacturer Old Crow Modular
HP 30
Depth No
+12V No
-12V No
+5V No
Additional Resources Build Guide & BOM


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