I'm having much difficulty modifying a "state variable" bandpass filter from being dual supply to single supply. (https://www.electronics-tutorials.ws/filter/state-variable-filter.html)
But when I try changing the supply rails to what I think would work, I don't get much of anything at the output. I've tried variations on this but all them end up being down in the -50dB to -60dB range. What I've done is simply change all the negative rails over to ground, then changed the (+) terminals of the op amps to a bias voltage at half-rail (2.5V).
I'm not quite sure what's going wrong, and have been stuck for some time. Any help appreciated.
Edit: In response to the comment below, here is what you get when you change the AC source ground to vbias. Adding or removing the cap between V2 and R1 doesn't change much, adding or removing the 1M resistor also doesn't change much.
Update with answer: I picked an op amp at "random" in LTSpice's menu. Changing the type and adding the cap between the source and R1 fixed the simulation. I breadboarded the circuit below, but am still getting the response above - more debug necessary. But that is a separate issue and this question here is resolved. Here is what I ended up with. Thanks everyone!