Any easy sweeping EQ circuit?

[nguitar12]

Hi just wonder if any sweepable EQ circuit out there?
I need three knob for each band (Frequency, Q, Gain)
Any help would be greatly appreciated.

[R.G.]

My opinion of the overall best in terms of flexibility is the state variable filter. It offers the choice of high pass, low pass, bandpass and notch filters, with independently variable frequency and Q. In combination with another opamp or two, you get frequency, Q and boost/cut on separate pots.

You're now going to ask me for a schematic, I think. I'd have to go look one up. There are several on the net.

[Kipper4]

Here might be a reasonable place to start with a SVF


http://sound.westhost.com/articles/state-variable.htm

[lars-musik]

Maybe this is worth a try:
http://www.untrue.ch/test/ne-1/
The Yamaha NE-1 with variable Q-control. The circuit can be found at the "other" forum. Try "silent fly ne-1 q-control" in google.
I haven't built it yet, but it is on my short list.

[blackieNYC]

RG!  What about the wonderful Geofex parametric? Variable Q.  I built a one-band, and I love it! (So what's wrong with it?  I can take it.)
http://www.geofex.com/article_folders/eqs/paramet.htm