7 band passive eq!

[WGTP]

Is replacing the Op-amp with a Dist+ or Tube Screamer going to work?   Maybe one at input and the other at output. 

[Nasse]

I checked my archives, almost similar circuit, filter freqs are said to be 75, 150, 300, 600, 1200, 2400, 4800 Hz

Two caps slightly different values but not much, 3,3 nF is 1,5 nF and 39 pF is 25 pF in that version

[R.G.]

It's an interesting circuit to use as a starting place. I think it's in one of my Markus circuit collections books as well.

There is one issue with an all-passive design like this - low Q. The filter bandpasses have quite wide pass bands, as well as shallow-sloped skirts. They therefore interact a lot. The effect of any one knob is heavily affected by the two knobs on either side of it, and perhaps a knob beyond that.

Once you have to put a buffer in front of the filter array and a recovery amp after it, it might be a useful idea to compare this to the 7-band graph EQ, one example of which is here: http://geofex.com/Article_Folders/EQs/greqs.gif