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FRCL: Fixed low-pass filters (3HP - PCB/Panel set)
York Modular

FRCL: Fixed low-pass filters (3HP - PCB/Panel set)

8 in stock.

Regular price £14.99 £0.00 Unit price per
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Think of it as a buffered mult with an RC filter on each output, because that's basically what it is.

The outputs consist of a set of 1-pole RC filters - these roll off at 6dB/octave. You're not going to be getting shrieky resonance out of these, but they are good for 'tidying up' some sounds (lower frequencies are good at reducing the effects of high-frequency transients, aka 'pop'). Modules are cascadeable should you wish to increase the filtering effect.

The following are implemented, with their associated resistor/capacitor pairs in brackets should you feel the need to tinker.

  • 63Hz (R3/C1)
  • 250Hz (R4/C2)
  • 500Hz (R5/C3)
  • 1.5kHz (R6/C4)
  • 3kHz (R7/C5)
  • 5kHz (R8/C6)
  • 8kHz (R9/C7)

The exact cutoff frequency will depend on the accuracy of your components - pre-built modules will use E24 series resistors, although the BOM lists alternative values should you wish to do a DIY build using E96-series components instead. It's worth noting that the tolerances of capacitors are generally somewhat worse than those of resistors, so it's better to determine the exact capacitance of your capacitors and work from that.

I recommend the use of polythene film capacitors where required (the large capacitor footprints on the PCB) - you can use ceramic capacitors in extremeis. Similarly, if you want high-pass filters instead just swap the appropriate resistors and capacitors (a high-pass version of the module is planned, though)

If you want to use completely different values, feel free - the filter calculator at is a useful resource, but keep in mind that the markings on the panel won't match with reality.

THIS IS A PCB/PANEL SET - it is up to you to source appropriate componentry and do the build. I am assuming that by buying this item you know how to read a BOM and schematic. A power cable and right-angle power header are also included.

BOM/schematic can be found at: