[sdiy] Weird MFOS VCO max CV problem

[Olivier Gillet]

> There were some discussions about using a TL07x as an inverting integrator  in an OTA filter, many people had hang-up
> issues at power up. Using the same part a voltage follower (with the integtator cap to ground) worked perfectly
> every time...

I have seen this problem, but I think it's the other way round: I have
seen frequently a phase reversal "crash" with the "cap to ground +
follower" circuit when signal level was getting too high. Can happen
when self-oscillation is reached, when cutoff is increased (less
high-frequency attenuation -> higher level), or simply when a very hot
external signal is fed into the circuit. I have worked a lot with +/-
5V so there's not much headroom and it's easy to hit the rails - and
in this context seeing a TL072 with its +ve input not grounded raises
a red flag for me. Neil Johnson has compiled this list of op-amps that
do not phase-reverse:
http://www.milton.arachsys.com/nj71/index.php?menu=2&submenu=2&subsubmenu=2

Back to the topic at hand, are there schematics of the offending circuit?