EQ + (Engineer's Thumb x2+) = multiband comp.?

[samhay]

I don't think you have killed your op-amp. My guess is that there is either:
(1).  a short somewhere or a small resitor to ground rather than Vref. This may explain whay Vref is 1.7V - this is not a good thing, and what I would focus on first.
(2).  the LPF is set way lower than it should be, so it is barely passing any signal. This could happen if you R6 and/or R7 are >>1k of if the pot is >>100k or if the caps are not 10n and 22n. Does the HP signal sound essentlailly identical to the dry signal out of U1A?

[samhay]

After looking at Vallhagen's new PINKING 3 band distortion (http://www.diystompboxes.com/smfforum/index.php?topic=102861.msg929656#msg929656), I realised that I had not added any phase compensation to this design.
This is not a trivial task if you want to sweep the crossover frequency, and should not be a problem if we are using a subtractive method to generate our HPF. However, if it all starts working and you get a weird comb filter effect, then I guess we may have to have  a think about the crossover design.