I see it's an old thread, but why not to revive it - I had a problem with LFO ticking on my Maestro MP-1 build. I put an original TL072 into LFO circuit, but it had a lots of ticking. So I thought I could try with something else - I recently bought a batch of fake TL072 chips, and my IC tester couldn't even recognize them on automatic. Setting it to LM2904 helped ICs be recognized as working. So they are some kind of dual op amps, but definitely not TL0x2 JFET input family. So I tried to put that fake chip into circuit and, to my surprise, works great and no ticking at all! I have some other original dual opamps and I will certainly try with them, but I've found the use for those fake TL072!