frequency control of higher order filter with mono pot

[okmog]

Hi,

I would need a (low phase shift) 12 dB high-pass filter, where I can change the cut-off frequency just with a mono pot.
Is this possible, since a 12 dB filter is a 2-pole (when using caps and resistors) and the cut-off frequency of each pole has to be changed simultaneously and so I would need a stereo pot.

Any experiences?

 

[mickeymoose]

THAT app not 130 describes a VCA controlled state-variable filter. Not quite what you want but maybe a guide. E

 

[jcx]

its got one knob...

 

[okmog]

Thanks for your posts.

The mechanical solution would be probably too "expansive" 😉

VCA solution should work. Is this standard solution filter freq by a pot? I can't remember haven't seen VCAs in synthesizer filters ...

 

[phase_accurate]

If you impolement your filter as state-variable filter you might control it using CMOS analog switches and a pulse-width modulator.

Regards

Charles