DOD FX25B--Anyone have a schematic?

[Transmogrifox]

I just purchased a DOD FX25B off eBay.  I purchased it for the sole purpose of finding out if it's possible to mod it into a cool pedal.  The filter in it is solid.  It's a good OTA based 2nd order filter similar to what's found in many analog synthesizers (though more of the synth filters are 4rth order).  

Like any bad envelope filter, the envelope follower is lacking, and this is the main problem with it.   I listen to the filter sound and I rather like it--seems to be a pretty rich tone.  

Anyway, does anyone have a schematic for this?  It would make the modding go much more easily as I wouldn't have to spend so much time tracing the circuit board.

[Mark Hammer]

Try here: http://img.photobucket.com/albums/v474/mhammer/DOD_FX25.gif

[Mark Hammer]

Oops.  Go here: http://photobucket.com/albums/v474/mhammer/?action=view&current=DOD_FX25.gif

[Transmogrifox]

Thank you.  I may be able to turn it into something quite cool, yet.  I do like the sound of the filter itself, it's just a one-trick pony for the envelope control is all.

Oh--Mine is actually the GFX25 extreme series...blah blah blah

I believe it is identical other than the implementation of parametric control.  Am I correct in assuming the pot in the filter feedback loop is adjusting filter resonance?  I haven't sat to analyze it, so I'm looking at it intuitively.

The GFX25 has "blend", "Sensitivity", and "Range".  It appears that this filter (fx25) has "Sensitivity" and "Range".  This "Range" control is the control that appears to be more a resonance control than "range", however it is possible that this happens to effect the filter's resonant frequency more than resonance.  It is my intuition, though, that low "range" is just low Q, thus wider bandwidth, so the filter doesn't appear to sweep as high since the bandwidth is wide.

After spending some time looking at the PCB, most everything in the schematic you provided is identical, save the addition of one more op amp in the GFX25, presumably for the "Blend" control and additional buffering perhaps on the output.