Problem solved, avoid ti rc4558p for ic4. I found that in both pedals thouching with a finger (don't do this at home) pin2 of bias2 trimmer the delay pot noise disappear leaving intact the sound of the effect. Looking the scheme I saw bias2 pin2 goes to pin5 of ic4(b, +) so I replaced the ICs with something I had in my pocket, two tl072...and the zipper noise is gone! It's stange cause my reference mmd is full of rc4558p...maybe the new ones are crappy, maybe the circuit has something different, I don't know. I'll try some jrc4558d and dd to see what happens. Thak you for the support, have a nice day