ZVex 'Probes' and Resonant Filters

[T1bbles]

Hey guys,

I've built a few pedals now and I want to do something nice and original; by stealing ideas from everyone else!

When listening to demos of the EHX HOG I really liked the expression pedal/resonant filter combo, and I really want to recreate that sort of sound without spending £300.

Of course with an expression pedal this would simply be a case of buying one and plugging it into a filter to control the centre frequency, but I don't like expression pedals, they're big and lumbering, but I do like the look of those ZVex probes.

And so!

A) Does anyone know how these probes work? I assume you end up with a variable resistance, and that can be integrated into section B.

B) Does anyone have a layout or a schematic for an active filter with a centre frequency and Q control?

Thanks guys

Martin.

[frequencycentral]

http://www.diystompboxes.com/smfforum/index.php?topic=68566.0