distorsion comes in to the signal after an hour or so

[surchur]

I have been trying to identify a distortion that I can't get rid of. started a couple of weeks ago. About an hour or so after a session starts I'm getting distortion in the signal and it's going down to track. I've checked everything from the mic, tube pres (rossetta I think) and now I'm down to the 888 and considering somthing in the mac. I think it maybe be heat related, because it starts about an hour after everything is going on. so now I've opened up the mac and more spacing bettween things on the rack. But I don't know where next to check. could it be a faulty card? Has anyone had this type of problem?? please help me out we have run behind schedule on this project by two weeks now.

[InSights7]

What is your configuration?

[surchur]

Not the distortion is in the tracks it's fine for the first hour or so???

[5down1up]

if u turn it on the next day , the distortion is still in the tracks ??? did i get that right ??? or is it "just" if the error occures ?
i had distortion once in fact of
interface cables , wrong card setup and no air circulation for the interfaces ( especially the 888/24 ) . but that was hardware failures the distortion wasnt " in the tracks " if i recorded them without distortion ... clueless !!! good luck